id
stringlengths 9
16
| submitter
stringlengths 1
64
⌀ | authors
stringlengths 3
36.7k
| title
stringlengths 1
382
| comments
stringlengths 1
1.15k
⌀ | journal-ref
stringlengths 1
557
⌀ | doi
stringlengths 7
153
⌀ | report-no
stringlengths 1
479
⌀ | categories
stringlengths 5
125
| license
stringclasses 9
values | abstract
stringlengths 6
6.09k
| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0708.1949 | Stelios Kazantzidis | Stelios Kazantzidis (KIPAC/Stanford), James S. Bullock (UC Irvine),
Andrew R. Zentner (KICP/U.Chicago), Andrey V. Kravtsov (KICP/U.Chicago),
Leonidas A. Moustakas (JPL/Caltech) | Cold Dark Matter Substructure and Galactic Disks I: Morphological
Signatures of Hierarchical Satellite Accretion | Accepted version to appear in ApJ, 24 pages, 8 figures, LaTeX (uses
emulateapj.cls). Comparison between the simulated ring-like features and the
Monoceros ring stellar structure in the Milky Way performed; conclusions
unaltered | Astrophys.J.688:254-276,2008 | 10.1086/591958 | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | (Abridged) We conduct a series of high-resolution, dissipationless N-body
simulations to investigate the cumulative effect of substructure mergers onto
thin disk galaxies in the context of the LCDM paradigm of structure formation.
Our simulation campaign is based on a hybrid approach. Substructure properties
are culled directly from cosmological simulations of galaxy-sized cold dark
matter (CDM) halos. In contrast to what can be inferred from statistics of the
present-day substructure populations, accretions of massive subhalos onto the
central regions of host halos, where the galactic disk resides, since z~1
should be common occurrences. One host halo merger history is subsequently used
to seed controlled numerical experiments of repeated satellite impacts on an
initially-thin Milky Way-type disk galaxy. We show that these accretion events
produce several distinctive observational signatures in the stellar disk
including: a ring-like feature in the outskirts; a significant flare; a central
bar; and faint filamentary structures that (spuriously) resemble tidal streams.
The final distribution of disk stars exhibits a complex vertical structure that
is well-described by a standard ``thin-thick'' disk decomposition. We conclude
that satellite-disk encounters of the kind expected in LCDM models can induce
morphological features in galactic disks that are similar to those being
discovered in the Milky Way, M31, and in other disk galaxies. These results
highlight the significant role of CDM substructure in setting the structure of
disk galaxies and driving galaxy evolution. Upcoming galactic structure surveys
and astrometric satellites may be able to distinguish between competing
cosmological models by testing whether the detailed structure of galactic disks
is as excited as predicted by the CDM paradigm.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 19:13:07 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Jul 2008 17:31:56 GMT"
}
] | 2010-01-28T00:00:00 | [
[
"Kazantzidis",
"Stelios",
"",
"KIPAC/Stanford"
],
[
"Bullock",
"James S.",
"",
"UC Irvine"
],
[
"Zentner",
"Andrew R.",
"",
"KICP/U.Chicago"
],
[
"Kravtsov",
"Andrey V.",
"",
"KICP/U.Chicago"
],
[
"Moustakas",
"Leonidas A.",
"",
"JPL/Caltech"
]
] |
0708.1950 | Vivek M. Aji | Vivek Aji, Chandra Varma and Ilya Vekhter | Kondo effect in an Antiferromagnetic metal | null | null | null | null | cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the fate of a spin-1/2 impurity in the itinerant antiferromagnetic
metallic phase via a renormalization group analysis and a variational
calculation. The local moment - conduction electron interaction hamiltonian in
an antiferromagnetic metal is spin non-conserving. We show that for a general
location of the impurity, the Kondo singularities still occur, but the ground
state has a partially unscreened moment. We calculate the magnitude of this
residual moment and the variation of the spin polarization with energy for a
substitutional impurity as a function of the staggered magnetization. The usual
Kondo effect only occurs if the impurity is placed at points where the
magnetization is zero.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:05:02 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 2008 19:29:35 GMT"
}
] | 2008-06-05T00:00:00 | [
[
"Aji",
"Vivek",
""
],
[
"Varma",
"Chandra",
""
],
[
"Vekhter",
"Ilya",
""
]
] |
0708.1951 | Sam Nelson | Sam Nelson and Jacquelyn L. Rische | On bilinear biquandles | 9 pages. To appear in Colloquium Mathematicum | Colloq. Math. 112 (2008) 279-289. | null | null | math.QA math.GT | null | We define a type of biquandle which is a generalization of symplectic
quandles. We use the extra structure of these bilinear biquandles to define new
knot and link invariants and give some examples.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:24:24 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Dec 2007 20:17:08 GMT"
}
] | 2008-08-13T00:00:00 | [
[
"Nelson",
"Sam",
""
],
[
"Rische",
"Jacquelyn L.",
""
]
] |
0708.1952 | Matteo Cardella Dr. | Eliezer Rabinovici | Spontaneous Breaking of Space-Time Symmetries | 37 pages, 18 figures. Based on the contribution to "String Theory and
Fundamental Interactions. Celebrating Gabriele Veneziano on his 65th
Birthday", edited by M. Gasperini and J. Maharana, to be published by
Springer, and Lecture given at Les Houches summer school: "String Theory and
The Real World From Particle Physics to Astrophysics", Session LXXXVII, 2007 | Lect.Notes Phys.737:573-605,2008 | null | null | hep-th | null | Kinematical and dynamical mechanisms leading to the spontaneous breaking of
space-time symmetries are described. The symmetries affected are space and time
translations, space rotations, scale and conformal transformations.
Applications are made to solidification, string theory compactifications, the
analysis of stable theories with no ground states, supersymmetry breaking and
the determination of the value of the vacuum energy.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:45:15 GMT"
}
] | 2015-03-13T00:00:00 | [
[
"Rabinovici",
"Eliezer",
""
]
] |
0708.1953 | Daniel A. Lidar | A. Shabani and D. A. Lidar (USC) | Linear Quantum Error Correction | This paper has been withdrawn as it has been superseded by
arXiv:0902.2478 | null | null | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a generalized theory of quantum error correction (QEC) that
applies to any linear map, in particular maps that are not completely positive
(CP). This theory describes entanglement-assisted QEC for invertible noise
maps, which we use to provides an example of the physical implementation of
non-CP recovery maps. We argue that a consistent map-based theory of
fault-tolerant QEC (whether Markovian or not) requires linear, non-CP maps, and
that this impacts the value of the fault-tolerance threshold.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:25:55 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Oct 2009 20:20:32 GMT"
}
] | 2009-10-21T00:00:00 | [
[
"Shabani",
"A.",
"",
"USC"
],
[
"Lidar",
"D. A.",
"",
"USC"
]
] |
0708.1954 | Eric Hallman | Jack O. Burns (1), Eric J. Hallman (1), Brennan Gantner (1), Patrick
M. Motl (2), Michael L. Norman (3) ((1) University of Colorado, (2) Louisiana
State University, (3) University of California-San Diego) | Why Do Only Some Galaxy Clusters Have Cool Cores? | 17 emulateapj pages, 17 figures, replaced with version accepted to
ApJ | null | 10.1086/526514 | null | astro-ph | null | Flux-limited X-ray samples indicate that about half of rich galaxy clusters
have cool cores. Why do only some clusters have cool cores while others do not?
In this paper, cosmological N-body + Eulerian hydrodynamic simulations,
including radiative cooling and heating, are used to address this question as
we examine the formation and evolution of cool core (CC) and non-cool core
(NCC) clusters. These adaptive mesh refinement simulations produce both CC and
NCC clusters in the same volume. They have a peak resolution of 15.6 h^{-1} kpc
within a (256 h^{-1} Mpc)^3 box. Our simulations suggest that there are
important evolutionary differences between CC clusters and their NCC
counterparts. Many of the numerical CC clusters accreted mass more slowly over
time and grew enhanced cool cores via hierarchical mergers; when late major
mergers occurred, the CC's survived the collisions. By contrast, NCC clusters
experienced major mergers early in their evolution that destroyed embryonic
cool cores and produced conditions that prevented CC re-formation. As a result,
our simulations predict observationally testable distinctions in the properties
of CC and NCC beyond the core regions in clusters. In particular, we find
differences between CC versus NCC clusters in the shapes of X-ray surface
brightness profiles, between the temperatures and hardness ratios beyond the
cores, between the distribution of masses, and between their supercluster
environs. It also appears that CC clusters are no closer to hydrostatic
equilibrium than NCC clusters, an issue important for precision cosmology
measurements.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:46:25 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Nov 2007 21:33:07 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Burns",
"Jack O.",
""
],
[
"Hallman",
"Eric J.",
""
],
[
"Gantner",
"Brennan",
""
],
[
"Motl",
"Patrick M.",
""
],
[
"Norman",
"Michael L.",
""
]
] |
0708.1955 | Jeetain Mittal | Jeetain Mittal, Vincent K. Shen, Jeffrey R. Errington, Thomas M.
Truskett | Cofinement, entropy, and single-particle dynamics of equilibrium
hard-sphere mixtures | submitted to JCP | J. Chem. Phys. 127, 154513 (2007) | 10.1063/1.2795699 | null | cond-mat.soft cond-mat.stat-mech | null | We use discontinuous molecular dynamics and grand-canonical transition-matrix
Monte Carlo simulations to explore how confinement between parallel hard walls
modifies the relationships between packing fraction, self-diffusivity, partial
molar excess entropy, and total excess entropy for binary hard-sphere mixtures.
To accomplish this, we introduce an efficient algorithm to calculate partial
molar excess entropies from the transition-matrix Monte Carlo simulation data.
We find that the species-dependent self-diffusivities of confined fluids are
very similar to those of the bulk mixture if compared at the same,
appropriately defined, packing fraction up to intermediate values, but then
deviate negatively from the bulk behavior at higher packing fractions. On the
other hand, the relationships between self-diffusivity and partial molar excess
entropy (or total excess entropy) observed in the bulk fluid are preserved
under confinement even at relatively high packing fractions and for different
mixture compositions. This suggests that the partial molar excess entropy,
calculable from classical density functional theories of inhomogeneous fluids,
can be used to predict some of the nontrivial dynamical behaviors of fluid
mixtures in confined environments.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:32:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mittal",
"Jeetain",
""
],
[
"Shen",
"Vincent K.",
""
],
[
"Errington",
"Jeffrey R.",
""
],
[
"Truskett",
"Thomas M.",
""
]
] |
0708.1956 | Anne Ersbak Bang Nielsen | Anne E. B. Nielsen and Klaus M{\o}lmer | Transforming squeezed light into a large amplitude coherent state
superposition | 6 pages, 4 figures, v2: published version | Phys. Rev. A 76, 043840 (2007) | 10.1103/PhysRevA.76.043840 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A quantum superposition of two coherent states of light with small amplitude
can be obtained by subtracting a photon from a squeezed vacuum state. In
experiments this preparation can be made conditioned on the detection of a
photon in the field from a squeezed light source. We propose and analyze an
extended measurement strategy which allows generation of high fidelity coherent
state superpositions with larger amplitude.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:01:18 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Oct 2014 19:08:26 GMT"
}
] | 2014-10-09T00:00:00 | [
[
"Nielsen",
"Anne E. B.",
""
],
[
"Mølmer",
"Klaus",
""
]
] |
0708.1957 | Arturo Wong | Arturo Wong, Jesus A. Maytorena, Catalina Lopez-Bastidas and Francisco
Mireles | Spin torque contribution to the a.c. spin Hall conductivity | 8 pages, 4 figures, paper | null | 10.1103/PhysRevB.77.035304 | null | cond-mat.mes-hall | null | Using the recently proposed definition of a conserved spin-current operator
[J. Shi et al., Phys. Rev. Lett. 96, 076604 (2006)] we explore the frequency
dependent spin Hall conductivity for a two-dimensional electron gas with Rashba
and Dresselhaus spin-orbit interaction in response to an oscillating electric
field. We show that the optical spectrum of the spin Hall conductivity exhibit
remarkable changes when the new definition of spin current is applied. Such
behavior is mainly due to a significant contribution of the spin torque term
which is absent in the conventional form of the spin current. In addition, it
is observed that the magnitude and direction of the dynamic spin Hall current
strongly depends on the electric field frequency as with the interplay of the
spin-orbit coupling strengths.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:39:02 GMT"
},
{
"version": "v2",
"created": "Wed, 17 Oct 2007 22:44:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wong",
"Arturo",
""
],
[
"Maytorena",
"Jesus A.",
""
],
[
"Lopez-Bastidas",
"Catalina",
""
],
[
"Mireles",
"Francisco",
""
]
] |
0708.1958 | Gerald Marsh | Gerald E. Marsh | Charge, geometry, and effective mass | To appear in Foundations of Physics. 15 pages, 1 figure. Minor
changes and additions | null | 10.1007/s10701-008-9209-1 | null | gr-qc | null | Charge, like mass in Newtonian mechanics, is an irreducible element of
electromagnetic theory that must be introduced ab initio. Its origin is not
properly a part of the theory. Fields are then defined in terms of forces on
either masses--in the case of Newtonian mechanics, or charges in the case of
electromagnetism. General Relativity changed our way of thinking about the
gravitational field by replacing the concept of a force field with the
curvature of space-time. Mass, however, remained an irreducible element. It is
shown here that the Reissner-Nordstrom solution to the Einstein field equations
tells us that charge, like mass, has a unique space-time signature.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:41:00 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Jan 2008 20:27:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marsh",
"Gerald E.",
""
]
] |
0708.1959 | N. P. Ong | Joseph G. Checkelsky, Lu Li and N. P. Ong | The zero-energy state in graphene in a high magnetic field | 4 pages, 4 figures. Four new sub-figures have been added. Text
expanded to discuss data from more samples | Phys. Rev. Lett. 100, 206801 (2008) | 10.1103/PhysRevLett.100.206801 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | The fate of the charge-neutral Dirac point in graphene in a high magnetic
field $H$ has been investigated at low temperatures ($T\sim$ 0.3 K). In samples
with small $V_0$ (the gate voltage needed to access the Dirac point), the
resistance $R_0$ at the Dirac point diverges steeply with $H$, signalling a
crossover to an insulating state in intense field. The approach to the
insulating state is highly unusual. Despite the steep divergence in $R_0$, the
profile of $R_0$ vs. $T$ in fixed $H$ saturates to a $T$-independent value
below 2 K, consistent with charge carrying gapless excitations.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 20:54:27 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Dec 2007 15:41:25 GMT"
}
] | 2008-05-21T00:00:00 | [
[
"Checkelsky",
"Joseph G.",
""
],
[
"Li",
"Lu",
""
],
[
"Ong",
"N. P.",
""
]
] |
0708.1960 | Doug McKay | Edmond L. Berger, Martin M. Block, Douglas W. McKay and Chung-I Tan | Ultra-high energy neutrino scattering | 4 pages, 1 figure, 1 table; Title, abstract and text changed,
conclusions unchanged. Version accepted for publication in Physical Review D | Phys.Rev.D77:053007,2008 | 10.1103/PhysRevD.77.053007 | null | hep-ph astro-ph | null | Estimates are made of the ultra-high energy neutrino cross sections based on
an extrapolation to very small Bjorken x of the logarithmic Froissart
dependence in x shown previously to provide an excellent fit to the measured
proton structure function F_2^p(x,Q^2) over a broad range of the virtuality
Q^2. Expressions are obtained for both the neutral current and the charged
current cross sections. Comparison with an extrapolation based on perturbative
QCD shows good agreement for energies where both fit data, but our rates are as
much as a factor of 10 smaller for neutrino energies above 10^9 GeV, with
important implications for experiments searching for extra-galactic neutrinos.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:08:51 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Feb 2008 12:35:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Berger",
"Edmond L.",
""
],
[
"Block",
"Martin M.",
""
],
[
"McKay",
"Douglas W.",
""
],
[
"Tan",
"Chung-I",
""
]
] |
0708.1961 | Corey S. O'Hern | Gregg Lois, Jerzy Blawzdziewicz and Corey S. O'Hern | The jamming transition and new percolation universality classes in
particulate systems with attraction | 4 pages, 2 figures, 2 tables | Phys. Rev. Lett. 100, 028001 (2008) | 10.1103/PhysRevLett.100.028001 | null | cond-mat.soft cond-mat.stat-mech | null | We numerically study the jamming transition in particulate systems with
attraction by investigating their mechanical response at zero temperature. We
find three regimes of mechanical behavior separated by two critical
transitions--connectivity and rigidity percolation. The transitions belong to
different universality classes than their lattice counterparts, due to force
balance constraints. We also find that these transitions are unchanged at low
temperatures and resemble gelation transitions in experiments on colloidal and
silica gels.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:15:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lois",
"Gregg",
""
],
[
"Blawzdziewicz",
"Jerzy",
""
],
[
"O'Hern",
"Corey S.",
""
]
] |
0708.1962 | Mihai Oltean | Mihai Oltean, Oana Muntean | Exact Cover with light | 20 pages, 4 figures, New Generation Computing, accepted, 2007 | New Generation Computing, Springer-Verlag, Vol. 26, Issue 4, pp.
327-344, 2008 | 10.1007/s00354-008-0049-5 | null | cs.AR cs.DC | null | We suggest a new optical solution for solving the YES/NO version of the Exact
Cover problem by using the massive parallelism of light. The idea is to build
an optical device which can generate all possible solutions of the problem and
then to pick the correct one. In our case the device has a graph-like
representation and the light is traversing it by following the routes given by
the connections between nodes. The nodes are connected by arcs in a special way
which lets us to generate all possible covers (exact or not) of the given set.
For selecting the correct solution we assign to each item, from the set to be
covered, a special integer number. These numbers will actually represent delays
induced to light when it passes through arcs. The solution is represented as a
subray arriving at a certain moment in the destination node. This will tell us
if an exact cover does exist or not.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:41:55 GMT"
}
] | 2009-02-07T00:00:00 | [
[
"Oltean",
"Mihai",
""
],
[
"Muntean",
"Oana",
""
]
] |
0708.1963 | Zhiqiang Chen | Z. Chen, T. A. Tyson, K. H. Ahn, Z. Zhong, J. Hu | Origin of the Non-Linear Pressure Effects in Perovskite Manganites:
Buckling of Mn-O-Mn Bonds and Jahn-Teller Distortion of the MnO6 Octahedra
Induced by Pressure | 15 pages, 5 figures | null | null | null | cond-mat.mtrl-sci | null | High-pressure resistivity and x-ray diffraction have been measured on
La0.85MnO3-d. At low pressures the metal-insulator transition temperature (TMI)
increases linearly with pressure up to a critical pressure, P* ~ 3.4 GPa, which
is followed by reduction of TMI with increasing pressure. Analysis of the bond
distances and bond angles reveal that a bandwidth increase drives the in-crease
of TMI for pressure below P*. The reduction of TMI at higher pressures is found
to result from Jahn-Teller distortions of the MnO6 octahedra. The role of
anharmonic interatomic potential is discussed.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:44:27 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Mar 2008 12:34:38 GMT"
}
] | 2008-03-21T00:00:00 | [
[
"Chen",
"Z.",
""
],
[
"Tyson",
"T. A.",
""
],
[
"Ahn",
"K. H.",
""
],
[
"Zhong",
"Z.",
""
],
[
"Hu",
"J.",
""
]
] |
0708.1964 | Mihai Oltean | Mihai Oltean, Oana Muntean | Solving the subset-sum problem with a light-based device | 14 pages, 6 figures, Natural Computing, 2007 | Natural Computing, Springer-Verlag, Vol 8, Issue 2, pp. 321-331,
2009 | 10.1007/s11047-007-9059-3 | null | cs.AR cs.AI cs.DC | null | We propose a special computational device which uses light rays for solving
the subset-sum problem. The device has a graph-like representation and the
light is traversing it by following the routes given by the connections between
nodes. The nodes are connected by arcs in a special way which lets us to
generate all possible subsets of the given set. To each arc we assign either a
number from the given set or a predefined constant. When the light is passing
through an arc it is delayed by the amount of time indicated by the number
placed in that arc. At the destination node we will check if there is a ray
whose total delay is equal to the target value of the subset sum problem (plus
some constants).
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:46:32 GMT"
}
] | 2015-09-11T00:00:00 | [
[
"Oltean",
"Mihai",
""
],
[
"Muntean",
"Oana",
""
]
] |
0708.1965 | Enkelejd Hashorva | Enkelejd Hashorva | Tail Asymptotics and Estimation for Elliptical Distributions | 14 pages, minor changes, typos removed | null | null | null | math.PR math.ST stat.TH | null | Let (X,Y) be a bivariate elliptical random vector with associated random
radius in the Gumbel max-domain of attraction. In this paper we obtain a second
order asymptotic expansion of the joint survival probability P(X > x, Y> y) for
x,y large. Further, based on the asymptotic bounds we discuss some aspects of
the statistical modelling of joint survival probabilities and the survival
conditional excess probability.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 21:52:52 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Oct 2007 12:54:24 GMT"
},
{
"version": "v3",
"created": "Thu, 15 May 2008 05:30:02 GMT"
}
] | 2008-05-15T00:00:00 | [
[
"Hashorva",
"Enkelejd",
""
]
] |
0708.1966 | Daoxin Yao | D. X. Yao and E. W. Carlson | Incompatibility of modulated checkerboard patterns with the neutron
scattering resonance peak in cuprate superconductors | 5 pages, 5 figures, Fig.2 updated | Phys. Rev. B 77, 024503 (2008) | 10.1103/PhysRevB.77.024503 | null | cond-mat.supr-con cond-mat.str-el | null | Checkerboard patterns have been proposed in order to explain STM experiments
on the cuprates BSCCO and Na-CCOC. However the presence of these patterns has
not been confirmed by a bulk probe such as neutron scattering. In particular,
simple checkerboard patterns are inconsistent with neutron scattering data, in
that they have low energy incommsensurate (IC) spin peaks rotated 45 degrees
from the direction of the charge IC peaks. However, it is unclear whether other
checkerboard patterns can solve the problem. In this paper, we have studied
more complicated checkerboard patterns ("modulated checkerboards") by using
spin wave theory and analyzed noncollinear checkerboards as well. We find that
the high energy response of the modulated checkerboards is inconsistent with
neutron scattering results, since they fail to exhibit a resonance peak at
(pi,pi), which has recently been shown to be a universal feature of cuprate
superconductors. We further argue that the newly proposed noncollinear
checkerboard also lacks a resonance peak. We thus conclude that to date no
checkerboard pattern has been proposed which satisfies both the low energy
constraints and the high energy constraints imposed by the current body of
experimental data in cuprate superconductors.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:54:29 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jan 2008 23:15:23 GMT"
},
{
"version": "v3",
"created": "Sat, 8 Mar 2008 21:13:02 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Yao",
"D. X.",
""
],
[
"Carlson",
"E. W.",
""
]
] |
0708.1967 | Stephen C. Davis | Stephen C. Davis | Solar System Constraints on Gauss-Bonnet Dark Energy | 4 pages, PASCOS-07 conference proceedings | AIPConf.Proc.957:379-382,2007 | 10.1063/1.2823806 | null | hep-th | null | Quadratic curvature Gauss-Bonnet gravity may be the solution to the dark
energy problem, but a large coupling strength is required. This can lead to
conflict with laboratory and planetary tests of Newton's law, as well as light
bending. The corresponding constraints are derived. If applied directly to
cosmological scales, the resulting bound on the density fraction is |Omega_GB|
< 3.6 x 10^-32.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:19:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Davis",
"Stephen C.",
""
]
] |
0708.1968 | Gabriel Tucci | Gabriel H. Tucci | Some quasinilpotent generators of the hyperfinite $\mathrm{II}_1$ factor | 26 pages | null | null | null | math.OA math.FA | null | For each sequence $\{c_n\}_n$ in $l_{1}(\N)$ we define an operator $A$ in the
hyperfinite $\mathrm{II}_1$-factor $\mathcal{R}$. We prove that these operators
are quasinilpotent and they generate the whole hyperfinite
$\mathrm{II}_1$-factor. We show that they have non-trivial, closed, invariant
subspaces affiliated to the von Neumann algebra and we provide enough evidence
to suggest that these operators are interesting for the hyperinvariant subspace
problem. We also present some of their properties. In particular, we show that
the real and imaginary part of $A$ are equally distributed, and we find a
combinatorial formula as well as an analytical way to compute their moments. We
present a combinatorial way of computing the moments of $A^{*}A$.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:06:25 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Tucci",
"Gabriel H.",
""
]
] |
0708.1969 | Daniel Allcock | Daniel Allcock | Linear Algebraic Groups without the Normalizer Theorem | 6 pages | null | null | null | math.RT math.AG | null | One can develop the basic structure theory of linear algebraic groups (the
root system, Bruhat decomposition, etc.) in a way that bypasses several major
steps in the standard development, including the self-normalizing property of
Borel subgroups.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:11:51 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Allcock",
"Daniel",
""
]
] |
0708.1970 | N. Langer | N. Langer, C. A. Norman, A. de Koter, Jorick Vink, M. Cantiello,
S.-C.Yoon | Pair creation supernovae at low and high redshift | submitted to A&A | null | 10.1051/0004-6361:20078482 | null | astro-ph | null | Pair creation supernovae (PCSN) are thought to be produced from very massive
low metallicity stars. The spectacularly bright SN 2006gy does show signatures
expected from PCSNe. Here, we investigate the metallicity threshold below which
PCSN can form and estimate their occurrence rate. We perform stellar evolution
calculations for stars of 150$\mso$ and 250$\mso$ of low metallicity
(Z$_{\odot}$/5 and Z$_{\odot}$/20), and analyze their mass loss rates. We find
that the bifurcation between quasi-chemically homogeneous evolution for fast
rotation and conventional evolution for slower rotation, which has been found
earlier for massive low metallicity stars, persists in the mass range
considered here. Consequently, there are two separate PCSN progenitor types:
(I) Fast rotators produce PCSNe from very massive Wolf-Rayet stars, and (II)
Slower rotators that generate PCSNe in hydrogen-rich massive yellow
hypergiants. We find that hydrogen-rich PCSNe could occur at metallicities as
high as Z$_{\odot}$/3, which -- assuming standard IMFs are still valid to
estimate their birth rates -- results in a rate of about one PCSN per 1000
supernovae in the local universe, and one PCSN per 100 supernovae at a redshift
of $z=5$. PCSNe from WC-type Wolf-Rayet stars are restricted to much lower
metallicity.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:15:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Langer",
"N.",
""
],
[
"Norman",
"C. A.",
""
],
[
"de Koter",
"A.",
""
],
[
"Vink",
"Jorick",
""
],
[
"Cantiello",
"M.",
""
],
[
"Yoon",
"S. -C.",
""
]
] |
0708.1971 | Eduardo Candelario-Jalil | E. Candelario-Jalil, H. H. Ajamieh, S. Sam, G. Martinez, O. S. Leon | Nimesulide limits kainate-induced oxidative damage in the rat
hippocampus | null | European Journal of Pharmacology 390(3): 295-298 (2000) | null | null | q-bio.TO | null | Kainate induces a marked expression of cyclooxygenase-2 after its systemic
administration. Because cyclooxygenase-2 activity is associated to the
production of reactive oxygen species, we investigated the effects of
nimesulide, a selective cyclooxygenase-2 inhibitor, on kainate-induced in vivo
oxidative damage in the rat hippocampus. A clinically relevant dose of
nimesulide (6 mg/kg, i.p.) was administered three times following kainate
application (9 mg/kg, i.p.). After 24 h of kainate administration, the drastic
decrease in hippocampal glutathione content and the significant increase in
lipid peroxidation were attenuated in nimesulide-treated rats, suggesting that
the induction of cyclooxygenase-2 is involved in kainate-mediated free radicals
formation.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:30:36 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Candelario-Jalil",
"E.",
""
],
[
"Ajamieh",
"H. H.",
""
],
[
"Sam",
"S.",
""
],
[
"Martinez",
"G.",
""
],
[
"Leon",
"O. S.",
""
]
] |
0708.1972 | W. Desmond Ramsay | Qweak Collaboration: Willem T. H. van Oers | The Qweak Experiment -- A search for new physics at the TeV Scale | 9 pages, 2 figures, LaTeX, uses elsart.cls and elsart1p.cls Invited
talk at International Nuclear Physics Conference 2007 (INCP2007), Tokyo,
Japan, June 3-8, 2007 | Nucl.Phys.A805:329-337,2008 | 10.1016/j.nuclphysa.2008.02.274 | TRI-PP-07-17 | nucl-ex | null | A new precision measurement of the parity violating analyzing power in
longitudinally polarized electron scattering from the proton at very low Q^2 at
an incident energy of 1.16 GeV is in the final stages of preparation for
execution at Jefferson Laboratory (JLab). A 2200 hour measurement of the parity
violating asymmetry in elastic electron-proton scattering at Q^2 = 0.03
(GeV/c)^2 employing 180 microamp of 85% polarized beam on a 0.35 m long liquid
hydrogen target will determine the weak charge of the proton, Q_w = 1 -
4sin^2(theta_W), with 4% combined statistical and systematic errors. The
Standard Model makes a firm prediction of Q_w, based on the `running' of the
weak mixing angle sin^2(theta_W) from the Z-pole down to lower energies. Any
significant deviation of sin^2(theta_W) from its Standard Model prediction at
low Q^2 would constitute a signal of new physics. In the absence of new
physics, the envisaged experiment will provide a 0.3% determination of
sin^2(theta_W), making this a very competitive measurement of the weak mixing
angle. Complementary to the present experiment is a measurement of the weak
charge of the electron in parity violating Moller scattering at 11 GeV,
currently under consideration, with the upgraded CEBAF at JLab. The objective
of that experiment would be a measurement of sin2(theta_W) with a precision
comparable to or better than any individual measurement at the Z-pole.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:36:23 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Qweak Collaboration",
"",
""
],
[
"van Oers",
"Willem T. H.",
""
]
] |
0708.1973 | Christoph Wildfeuer F. | Christoph F. Wildfeuer, Jonathan P. Dowling | Strong violations of Bell-type inequalities for Werner-like states | Revised manuscript, accepted for publication in PRA | Phys. Rev. A 78, 032113 (2008) | 10.1103/PhysRevA.78.032113 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the violation of Bell-type inequalities for two-qubit
Werner-like states parametrized by the positive parameter 0<p<1. We use an
unbalanced homodyne detection scheme to obtain the quantum mechanical
probabilities. A violation of the Bell-Wigner and Janssens inequalities is
obtained for a large range of the parameter p. The range given by these
inequalities is greater than the one given by the Clauser-Horne inequality. The
range in which a violation is attained actually coincides with the range where
the Werner-like states are known to be nonseparabel, i.e., for p>1/3. However,
the improvement over the Clauser-Horne inequality is achieved at the price of
restricting the class of possible local hidden variable theories.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 15:13:36 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Oct 2007 00:45:23 GMT"
},
{
"version": "v3",
"created": "Fri, 8 Feb 2008 13:51:46 GMT"
},
{
"version": "v4",
"created": "Fri, 12 Sep 2008 15:50:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wildfeuer",
"Christoph F.",
""
],
[
"Dowling",
"Jonathan P.",
""
]
] |
0708.1974 | Igor Moskalenko | Igor V. Moskalenko (Stanford), Andrew W. Strong (MPE), Troy A. Porter
(UCSC) | Isotopic composition of cosmic-ray sources | 4 pages, 2 figures. Contribution to the 30th ICRC, Merida, Mexico,
2007 (final version) | Proc. 30th ICRC (Merida), 2, 129-132 (2007) | null | null | astro-ph | null | We use the GALPROP code and the Advanced Composition Explorer (ACE) data to
derive the cosmic ray (CR) isotopic composition at the sources. The composition
is derived for two propagation models, diffusive reacceleration and plain
diffusion. We show that the compositions derived assuming these two propagation
models are different. We also compare the isotopic composition at the sources
with the latest solar composition.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:20:32 GMT"
}
] | 2009-02-25T00:00:00 | [
[
"Moskalenko",
"Igor V.",
"",
"Stanford"
],
[
"Strong",
"Andrew W.",
"",
"MPE"
],
[
"Porter",
"Troy A.",
"",
"UCSC"
]
] |
0708.1975 | Prof. Dr. M. W. Wu | M. Q. Weng, M. W. Wu, H. L. Cui | Spin relaxation in $n$-type GaAs quantum wells with transient spin
grating | 9 pages, 4 figures, to be published in JAP | J. Appl. Phys. 103, 063714 (2008). | 10.1063/1.2899962 | null | cond-mat.mtrl-sci | null | By solving the kinetic spin Bloch equations, we study the time evolution of
the transient spin grating, whose spin polarization varies periodically in real
space, confined in (001) GaAs quantum wells. With this study we can investigate
the properties of both the spin transport and the spin relaxation at the same
time. The Fourier component of the spin signal decays double exponentially with
two decay rates $1/\tau_+$ and $1/\tau_-$. In high temperature regime, the
average of these two rates varies with the grating wave-vector $q$
quadratically, i.e., $(1/\tau_++1/\tau_-)/2=D_sq^2+1/\tilde{\tau}_s$, with
$D_s$ and $\tilde{\tau}_s$ representing the spin diffusion coefficient and the
average of the out-of-plane and the in-plane spin relaxation times
respectively. $\tau_{\pm}$ calculated from our theory are in good agreement
with the experimental data by Weber {\em et al.} [Phys. Rev. Lett. {\bf 98},
076604 (2007)]. By comparing $D_s$ with and without the electron-electron
Coulomb scattering, we calculate the contribution of Coulomb drag to the spin
diffusion coefficient. With the transient spin grating result, we further
reveal the relations among different characteristic parameters such as spin
diffusion coefficient $D_s$, spin relaxation time $\tau_s$, and spin injection
length $L_s$. We show that in the presence of the Dresselhaus and/or Rashba
spin-orbit coupling, the widely used relation $L_s=\sqrt{D_s\tau_s}$ is
generally inaccurate and can even be very wrong in some special cases. We
present an accurate way to extract the steady-state transport characteristic
parameters from the transient spin grating signals.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:35:38 GMT"
},
{
"version": "v2",
"created": "Fri, 14 Dec 2007 03:43:33 GMT"
},
{
"version": "v3",
"created": "Sat, 26 Jan 2008 20:53:37 GMT"
},
{
"version": "v4",
"created": "Tue, 29 Jan 2008 08:40:53 GMT"
}
] | 2008-03-23T00:00:00 | [
[
"Weng",
"M. Q.",
""
],
[
"Wu",
"M. W.",
""
],
[
"Cui",
"H. L.",
""
]
] |
0708.1976 | Kaixuan Ni | K. Ni, R. Hasty, T. M. Wongjirad, L. Kastens, A. Manzur, D. N.
McKinsey | Preparation of Neutron-activated Xenon for Liquid Xenon Detector
Calibration | to be published in NIM A, corrected typos in Table 1 and Fig.6 of the
previous version | Nucl.Instrum.Meth.A582:569-574,2007 | 10.1016/j.nima.2007.08.180 | null | physics.ins-det astro-ph nucl-ex | null | We report the preparation of neutron-activated xenon for the calibration of
liquid xenon (LXe) detectors. Gamma rays from the decay of xenon metastable
states, produced by fast neutron activation, were detected and their activities
measured in a LXe scintillation detector. Following a five-day activation of
natural xenon gas with a Cf-252 (4 x 10^5 n/s) source, the activities of two
gamma ray lines at 164 keV and 236 keV, from Xe-131m and Xe-129m metastable
states, were measured at about 95 and 130 Bq/kg, respectively. We also observed
three additional lines at 35 keV, 100 keV and 275 keV, which decay away within
a few days. No long-lifetime activity was observed after the neutron
activation.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:39:22 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 18:19:54 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ni",
"K.",
""
],
[
"Hasty",
"R.",
""
],
[
"Wongjirad",
"T. M.",
""
],
[
"Kastens",
"L.",
""
],
[
"Manzur",
"A.",
""
],
[
"McKinsey",
"D. N.",
""
]
] |
0708.1977 | Asan Damanik | Asan Damanik, Mirza Satriawan, Arief Hermanto, Pramudita Anggraita | Truly Minimal Left-Right Symmetry Model for Electroweak Interaction | 6 pages, no figure | null | null | null | hep-ph | null | By using two primary doublets and one induced bidoublet Higgs fields as a
result of the interactions of the two doublets, we evaluate the predictive
power of the left-right symmetry model based on $SU(2)_{L}\otimes
SU(2)_{R}\otimes U(1)$ gauge group to the gauge bosons masses, leptons masses,
and the structure of electroweak interactions. We found that the contribution
of the right charge-current to the electroweak interaction is only around
0.0073 percent. The neutrino mass emerges naturally without introducing exotic
particles. We obtain that the mixing angle $\theta = 45^{0}$ for boson sector,
$\theta \approx 45^{0}$ for neutrino sector, and $\theta = 0^{0}$ for electron
sector. The parity violation in our model could be associated with the mass
mixing in the bosons and leptons masses arise from the induced bidoublet Higgs
via symmetry breaking.
PACs: 12.60.Cn; 12.60.Fr
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:56:44 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Damanik",
"Asan",
""
],
[
"Satriawan",
"Mirza",
""
],
[
"Hermanto",
"Arief",
""
],
[
"Anggraita",
"Pramudita",
""
]
] |
0708.1978 | Nikolai Dokuchaev | Nikolai Dokuchaev | Parabolic equations with the second order Cauchy conditions on the
boundary | 7 pages | Journal of Physics A: Mathematical and Theoretical. (2007) 40, pp.
12409--12413 | 10.1088/1751-8113/40/41/010 | null | math.AP math-ph math.MP | null | The paper studies some ill-posed boundary value problems on semi-plane for
parabolic equations with homogenuous Cauchy condition at initial time and with
the second order Cauchy condition on the boundary of the semi-plane. A class of
inputs that allows some regularity is suggested and described explicitly in
frequency domain. This class is everywhere dense in the space of square
integrable functions.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 01:57:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dokuchaev",
"Nikolai",
""
]
] |
0708.1979 | Saharon Shelah's Office | Saharon Shelah | Advances in Cardinal Arithmetic | null | In: Finite and Infinite Combinatorics in Sets and Logic, 355-383,
Kluwer Academic Publishers 1993, N.W. Sauer et al (eds.) | null | Shelah [Sh:420] | math.LO | null | If cf(kappa) = kappa, kappa^+< cf(lambda) = \lambda, then there is a
stationary subset S of {delta<lambda:cf(delta)=kappa} in I[lambda]. Moreover,
we can find <C_delta :delta in S>, C_delta a club of lambda,
otp(C_delta)=kappa, guessing clubs and for each alpha<lambda we have: {C_delta
\cap alpha: alpha \in nacc(C_delta)} has cardinality <lambda. Also, we prove
that e.g. there is a stationary subset of S_{<aleph_1}(lambda) of cardinality
cf(S_{<aleph_1}(lambda),subseteq) Then we prove the existence of nice filters
when instead being normal filters on omega_1 they are normal filters with
larger domains, which can increase during a play. They can help us transfer
situation on aleph_1-complete filters to normal ones
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:07:00 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jun 2008 17:16:17 GMT"
}
] | 2008-06-03T00:00:00 | [
[
"Shelah",
"Saharon",
""
]
] |
0708.1980 | Saharon Shelah's Office | Saharon Shelah | The first almost free Whitehead group | null | null | null | Shelah [Sh:914] | math.LO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Assume G.C.H. and kappa is the first uncountable cardinal such that there is
a kappa-free abelian group which is not a Whitehead (abelian) group. We prove
that kappa is necessarily an inaccessible cardinal
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:15:16 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Mar 2009 20:16:18 GMT"
},
{
"version": "v3",
"created": "Fri, 10 Jun 2011 04:52:40 GMT"
}
] | 2011-06-13T00:00:00 | [
[
"Shelah",
"Saharon",
""
]
] |
0708.1981 | Saharon Shelah's Office | Saharon Shelah | On some problems in general topology | null | In: Set Theory, Boise ID, 1992-1994, Contemporary Mathematics, vol
192, p. 91-101 | null | null | math.LO | null | We prove that Arhangelskii's problem has a consistent positive answer: if
V\models CH, then for some aleph_1-complete aleph_2-c.c. forcing notion P of
cardinality aleph_2 we have that P forces ``CH and there is a Lindelof regular
topological space of size aleph_2 with clopen basis with every point of
pseudo-character aleph_0 (i.e. each singleton is the intersection of countably
many open sets)''.
Also, we prove the consistency of: CH+ 2^{aleph_1} > \aleph_2 + "there is no
space as above with aleph_2 points" (starting with a weakly compact cardinal).
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:24:41 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Shelah",
"Saharon",
""
]
] |
0708.1982 | Akira Masuoka | Akira Masuoka | Abelian and non-abelian second cohomologies of quantized enveloping
algebras | 40 Pages, the final version to appear in J. Algebra; mainly, typos
corrected | null | null | null | math.QA | null | For a class of pointed Hopf algebras including the quantized enveloping
algebras, we discuss cleft extensions, cocycle deformations and the second
cohomology. We present such a non-standard method of computing the abelian
second cohomology that derives information from the non-abelian second
cohomology classifying cleft extensions. As a sample computation, a quantum
analogue of Whitehead's second lemma for Lie-algebra cohomology is proved.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:31:45 GMT"
},
{
"version": "v2",
"created": "Sun, 23 Sep 2007 07:20:10 GMT"
},
{
"version": "v3",
"created": "Fri, 4 Jan 2008 06:16:54 GMT"
},
{
"version": "v4",
"created": "Mon, 21 Apr 2008 02:38:34 GMT"
}
] | 2008-04-21T00:00:00 | [
[
"Masuoka",
"Akira",
""
]
] |
0708.1983 | Peter Freund | Peter G. O. Freund | Two-component Duality and Strings | added references | null | null | null | hep-th hep-ph physics.hist-ph | null | A phenomenologically successful two-component hadronic duality picture led to
Veneziano's amplitude, the fundamental first step to string theory. This
picture is briefly recalled and its two components are identified as the open
strings (mesons and baryons) and closed strings (Pomeron).
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:34:35 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Sep 2007 15:58:23 GMT"
}
] | 2007-09-12T00:00:00 | [
[
"Freund",
"Peter G. O.",
""
]
] |
0708.1984 | Saharon Shelah's Office | Saharon Shelah | Density is at most the spread of the square | null | null | null | Shelah [Sh:E56] | math.LO | null | We show the following result:
Assume B is an infinite Boolean Algebra and lambda=d(B). Then s(B*B)$, i.e.
s(uf(B)xuf(B))>= lambda$ (if lambda limit - obtained)
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 02:56:57 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Shelah",
"Saharon",
""
]
] |
0708.1985 | Sonjoy Majumder | Gopal Dixit, B. K. Sahoo, R. K. Chaudhuri and Sonjoy Majumder | Relativistic ab initio study of forbidden transitions of singly ionized
Zinc using CCSD(T) | 9 pages | null | null | null | physics.atom-ph physics.comp-ph | null | In this work, the {\it ab initio} calculations have been carried out to study
the oscillator strengths corresponding to `forbidden transitions' of
astrophysically important electromagnetic transitions of singly ionized zinc,
Zn II. Many important electron correlations are considered to all-orders using
the relativistic coupled-cluster theory. Calculated ionization potentials are
compared with the experimental values, wherever available. To our knowledge,
oscillator strengths of magnetic dipole and electric quardupole transitions are
estimated for the first time. The transitions span in the range of ultraviolet,
visible, and near infrared regions and are important for astrophysical
observations.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 03:09:54 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 16:25:01 GMT"
}
] | 2007-08-20T00:00:00 | [
[
"Dixit",
"Gopal",
""
],
[
"Sahoo",
"B. K.",
""
],
[
"Chaudhuri",
"R. K.",
""
],
[
"Majumder",
"Sonjoy",
""
]
] |
0708.1986 | Gui Lu Long | Gui Lu Long and Yang Liu | Duality and Recycling Computing in Quantum Computers | 4 pages and 3 figures | null | 10.1088/0253-6102/50/6/11 | null | quant-ph | null | Quantum computer possesses quantum parallelism and offers great computing
power over classical computer \cite{er1,er2}. As is well-know, a moving quantum
object passing through a double-slit exhibits particle wave duality. A quantum
computer is static and lacks this duality property. The recently proposed
duality computer has exploited this particle wave duality property, and it may
offer additional computing power \cite{r1}. Simply put it, a duality computer
is a moving quantum computer passing through a double-slit. A duality computer
offers the capability to perform separate operations on the sub-waves coming
out of the different slits, in the so-called duality parallelism. Here we show
that an $n$-dubit duality computer can be modeled by an $(n+1)$-qubit quantum
computer. In a duality mode, computing operations are not necessarily unitary.
A $n$-qubit quantum computer can be used as an $n$-bit reversible classical
computer and is energy efficient. Our result further enables a $(n+1)$-qubit
quantum computer to run classical algorithms in a $O(2^n)$-bit classical
computer. The duality mode provides a natural link between classical computing
and quantum computing. Here we also propose a recycling computing mode in which
a quantum computer will continue to compute until the result is obtained. These
two modes provide new tool for algorithm design. A search algorithm for the
unsorted database search problem is designed.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 03:17:30 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Long",
"Gui Lu",
""
],
[
"Liu",
"Yang",
""
]
] |
0708.1987 | Toshiyuki Fukushige | Tomoaki Ishiyama, Toshiyuki Fukushige, Junichiro Makino | Environmental effect on the subhalo abundance -- a solution to the
missing dwarf problem | 8 pages, 5 figures, higher resolution run added, accepted by PASJ | null | 10.1093/pasj/60.4.L13 | null | astro-ph | null | Recent high-resolution simulations of the formation of dark-matter halos have
shown that the distribution of subhalos is scale-free, in the sense that if
scaled by the velocity dispersion of the parent halo, the velocity distribution
function of galaxy-sized and cluster-sized halos are identical. For
cluster-sized halos, simulation results agreed well with observations.
Simulations, however, predicted far too many subhalos for galaxy-sized halos.
Our galaxy has several tens of known dwarf galaxies. On the other hands,
simulated dark-matter halos contain thousands of subhalos. We have performed
simulation of a single large volume and measured the abundance of subhalos in
all massive halos. We found that the variation of the subhalo abundance is very
large, and those with largest number of subhalos correspond to simulated halos
in previous studies. The subhalo abundance depends strongly on the local
density of the background. Halos in high-density regions contain large number
of subhalos. Our galaxy is in the low-density region. For our simulated halos
in low-density regions, the number of subhalos is within a factor of three to
that of our galaxy. We argue that the ``missing dwarf problem'' is not a real
problem but caused by the biased selection of the initial conditions in
previous studies, which were not appropriate for field galaxies.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 03:31:13 GMT"
},
{
"version": "v2",
"created": "Wed, 28 May 2008 02:20:44 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Ishiyama",
"Tomoaki",
""
],
[
"Fukushige",
"Toshiyuki",
""
],
[
"Makino",
"Junichiro",
""
]
] |
0708.1988 | Arthur D. Yaghjian | Arthur D. Yaghjian, Terry H. O'Donnell, Edward E. Altshuler, Steven R.
Best | Electrically Small Supergain Arrays | 10 pages, 11 figures, submitted to IEEE Transactions on Antennas and
Propagation (December 2006) | Published in Radio Science, vol. 43, RS3002, 2008 | 10.1029/2007RS003747 | null | physics.class-ph | null | The theory, computer simulations, and experimental measurements are presented
for electrically small two-element supergain arrays with near optimal endfire
gains of 7 dB. We show how the difficulties of narrow tolerances, large
mismatches, low radiation efficiencies, and reduced scattering of electrically
small parasitic elements are overcome by using electrically small resonant
antennas as the elements in both separately driven and singly driven
(parasitic) two-element electrically small supergain endfire arrays. Although
rapidly increasing narrow tolerances prevent the practical realization of the
maximum theoretically possible endfire gain of electrically small arrays with
many elements, the theory and preliminary numerical simulations indicate that
near maximum supergains are also achievable in practice for electrically small
arrays with three (and possibly more) resonant elements if the decreasing
bandwidth with increasing number of elements can be tolerated.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 04:12:27 GMT"
}
] | 2009-01-28T00:00:00 | [
[
"Yaghjian",
"Arthur D.",
""
],
[
"O'Donnell",
"Terry H.",
""
],
[
"Altshuler",
"Edward E.",
""
],
[
"Best",
"Steven R.",
""
]
] |
0708.1989 | Hiroshi Suzuki | Yoshio Kikukawa and Hiroshi Suzuki | Four-dimensional lattice chiral gauge theories with anomalous fermion
content | 18 pages, the final version to appear in JHEP | JHEP 0710:018,2007 | 10.1088/1126-6708/2007/10/018 | UT-Komaba/07-13, RIKEN-TH-109 | hep-lat hep-th | null | In continuum field theory, it has been discussed that chiral gauge theories
with Weyl fermions in anomalous gauge representations (anomalous gauge
theories) can consistently be quantized, provided that some of gauge bosons are
permitted to acquire mass. Such theories in four dimensions are inevitablly
non-renormalizable and must be regarded as a low-energy effective theory with a
finite ultraviolet (UV) cutoff. In this paper, we present a lattice framework
which enables one to study such theories in a non-perturbative level. By
introducing bare mass terms of gauge bosons that impose ``smoothness'' on the
link field, we explicitly construct a consistent fermion integration measure in
a lattice formulation based on the Ginsparg-Wilson (GW) relation. This
framework may be used to determine in a non-perturbative level an upper bound
on the UV cutoff in low-energy effective theories with anomalous fermion
content. By further introducing the St\"uckelberg or Wess-Zumino (WZ) scalar
field, this framework provides also a lattice definition of a non-linear sigma
model with the Wess-Zumino-Witten (WZW) term.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 04:44:18 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Aug 2007 07:00:56 GMT"
},
{
"version": "v3",
"created": "Mon, 1 Oct 2007 00:42:26 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Kikukawa",
"Yoshio",
""
],
[
"Suzuki",
"Hiroshi",
""
]
] |
0708.1990 | Shunsuke Takagi | Karl Schwede and Shunsuke Takagi | Rational singularities associated to pairs | 31 pages; v.4: a minor mistake in the characteristic p theory is
corrected, see Remark 1.1 for details | Michigan Math. J. 57 (2008), 625--658 | null | null | math.AG math.AC | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we introduce a notion of rational singularities associated to
pairs $(X, \ba^t)$ where $X$ is a variety, $\ba$ is an ideal sheaf and $t$ is a
nonnegative real number. We prove that most standard results about rational
singularities extend to this context. We also show that some results commonly
associated with log terminal pairs have analogs in this context, including
results related to inversion of adjunction. A positive characteristic analogue
of rational singularities of pairs is also defined and explored.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:11:21 GMT"
},
{
"version": "v2",
"created": "Sun, 2 Dec 2007 15:24:15 GMT"
},
{
"version": "v3",
"created": "Fri, 18 Jan 2008 22:19:36 GMT"
},
{
"version": "v4",
"created": "Thu, 12 Mar 2009 12:56:41 GMT"
}
] | 2009-04-28T00:00:00 | [
[
"Schwede",
"Karl",
""
],
[
"Takagi",
"Shunsuke",
""
]
] |
0708.1991 | Niranjan Joshi Dr. | N. V. Joshi | Conditions for the Trivers-Willard hypothesis to be valid: A minimal
population-genetic model | 14 pages including 4 figures | Journal of Genetics, Vol 79 issue 1, page 9-15 (2000) | null | null | q-bio.PE | null | The very insightful Trivers-Willard hypothesis, proposed in the early 1970s,
states that females in good physiological conditions are more likely to produce
male offspring, when the variance of reproductive success amongst males is
high. A number of studies, aimed at its experimental verification, have found
adequate supportive evidence in its favour. Theoretical investigations,
however, have been few, perhaps because formulating a population-genetic model
for describing the Trivers-Willard hypothesis turns out to be surprisingly
complex. The present study describes a minimal population genetic model to
explore one specific scenario, viz. how is the preference for a male offspring
by females in good condition altered when 'g', the proportion of such females
in the population changes from a low to a high value. As expected, when the
proportion of such females is low, i.e., for low values of 'g', the
Trivers-Willard (TW) strategy goes to fixation against the equal investment
strategy. This holds true up to gmax, a critical value of 'g', above which the
two strategies coexist, but the proportion of the TW strategy steadily
decreases as 'g' increases to unity. Similarly, when the effect of well-endowed
males attaining disproportionately high number of matings is more pronounced,
the TW strategy is more likely to go to fixation. Interestingly, the success of
the TW strategy has a complex dependence on the variance in the physiological
condition of females. If the difference in the two types of conditions is not
large, TW strategy is favoured, and its success is more likely as the
difference increases. However, beyond a critical value of the difference, the
TW strategy is found to be less and less likely to succeed as the difference
becomes larger. Possible reasons for these effects are discussed.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:00:45 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Joshi",
"N. V.",
""
]
] |
0708.1992 | Paul M. Terwilliger | Tatsuro Ito and Paul Terwilliger | Distance-regular graphs of $q$-Racah type and the $q$-tetrahedron
algebra | 15 pages | null | null | null | math.CO math.RT | null | In this paper we discuss a relationship between the following two algebras:
(i) the subconstituent algebra $T$ of a distance-regular graph that has
$q$-Racah type; (ii) the $q$-tetrahedron algebra $\boxtimes_q$ which is a
$q$-deformation of the three-point $sl_2$ loop algebra. Assuming that every
irreducible $T$-module is thin, we display an algebra homomorphism from
$\boxtimes_q$ into $T$ and show that $T$ is generated by the image together
with the center $Z(T)$.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:03:43 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Ito",
"Tatsuro",
""
],
[
"Terwilliger",
"Paul",
""
]
] |
0708.1993 | Zhao Lu | Zhao Lu and Michael A Lee | Dynamics of glucose-lactose diauxic growth in E. coli | This paper has been withdrawn by the author because it was a part of
the author's thesis | null | null | null | q-bio.OT q-bio.CB | null | We present a mathematical model of glucose-lactose diauxic growth in
Escherichia coli including both the postive and negative regulation mechanisms
of the lactose operon as well as the inducer exclusion. To validate this model,
we first calculated the time evolution of beta-galactosidase for only the
lactose nutrient and compared the numerical results with experimental data.
Second, we compared the calculated cell biomass of the glucose-lactose diauxic
growth with the experimental optical density of the diauxic growth for a
particular E. coli MG 1655. For both cases, the numerical calculations from
this model are in good agreement with these two experiments' data. The diauxic
growth pattern of a wild type E. coli was also investigated.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:31:21 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Jan 2011 18:54:14 GMT"
}
] | 2011-01-31T00:00:00 | [
[
"Lu",
"Zhao",
""
],
[
"Lee",
"Michael A",
""
]
] |
0708.1994 | Andy O'Bannon | Andy O'Bannon | Hall Conductivity of Flavor Fields from AdS/CFT | 22 pages, 4 figures | Phys.Rev.D76:086007,2007 | 10.1103/PhysRevD.76.086007 | null | hep-th | null | We use the AdS/CFT correspondence to compute a conductivity associated with
massive N=2 supersymmetric hypermultiplet fields at finite baryon density,
propagating through an N=4 supersymmetric SU(Nc) Yang-Mills plasma in the large
Nc, large 't Hooft coupling limit. We do so by introducing external electric
and magnetic fields coupled to baryon number and computing the resulting
induced current, from which we extract the conductivity tensor. At large
hypermultiplet mass we compute the drag force on the charge carriers. We also
compute the product of the drag coefficient with the kinetic mass, and find
that the answer is unchanged from the zero density case. The gravitational dual
is a probe D7-brane, with a nontrivial worldvolume gauge field configuration,
in an AdS-Schwarzschild background. We identify an effective horizon on the
D7-brane worldvolume analogous to the worldsheet horizon observed for strings
moving in the same background. We generalize our results to a class of theories
described by probe D-branes in various backgrounds.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:09:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"O'Bannon",
"Andy",
""
]
] |
0708.1995 | Jukka Pekola | Jukka P. Pekola, Juha J. Vartiainen, Mikko Mottonen, Olli-Pentti
Saira, Matthias Meschke, Dmitri V. Averin | Hybrid single-electron transistor as a source of quantized electric
current | 5 pages, 3 figures | null | 10.1038/nphys808 | null | cond-mat.mes-hall | null | The basis of synchronous manipulation of individual electrons in solid-state
devices was laid by the rise of single-electronics about two decades ago.
Ultra-small structures in a low temperature environment form an ideal domain of
addressing electrons one by one. A long-standing challenge in this field has
been the realization of a source of electric current that is accurately related
to the operation frequency $f$. There is an urgent call for a quantum standard
of electric current and for the so-called metrological triangle, where voltage
from Josephson effect and resistance from quantum Hall effect are tested
against current via Ohm's law for a consistency check of the fundamental
constants of Nature, $\hbar$ and $e$. Several attempts to create a metrological
current source that would comply with the demanding criteria of extreme
accuracy, high yield, and implementation with not too many control parameters
have been reported. However, no satisfactory solution exists as yet despite
many ingenious achievements that have been witnessed over the years. Here we
propose and prove the unexpected concept of a hybrid metal-superconductor
turnstile in the form of a one-island single-electron transistor with one gate,
which demonstrates robust current plateaus at multiple levels of $ef$ within
the uncertainty of our current measurement. Our theoretical estimates show that
the errors of the present system can be efficiently suppressed by further
optimizations of design and proper choice of the device parameters and
therefore we expect it to eventually meet the stringent specifications of
quantum metrology.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 06:33:51 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 06:02:23 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Pekola",
"Jukka P.",
""
],
[
"Vartiainen",
"Juha J.",
""
],
[
"Mottonen",
"Mikko",
""
],
[
"Saira",
"Olli-Pentti",
""
],
[
"Meschke",
"Matthias",
""
],
[
"Averin",
"Dmitri V.",
""
]
] |
0708.1996 | Ludger Harnau | L. Harnau, S. Kondrat and A. Poniewierski | Effective free energy method for nematic liquid crystals in contact with
structured substrates | 10 pages, 7 figures, submitted | null | 10.1103/PhysRevE.76.051701 | null | cond-mat.soft cond-mat.stat-mech | null | We study the phase behavior of a nematic liquid crystal confined between a
flat substrate with strong anchoring and a patterned substrate whose structure
and local anchoring strength we vary. By first evaluating an effective surface
free energy function characterizing the patterned substrate we derive an
expression for the effective free energy of the confined nematic liquid
crystal. Then we determine phase diagrams involving a homogeneous state in
which the nematic director is almost uniform and a hybrid aligned nematic state
in which the orientation of the director varies through the cell. Direct
minimization of the free energy functional were performed in order to test the
predictions of the effective free energy method. We find remarkably good
agreement between the phase boundaries calculated from the two approaches. In
addition the effective energy method allows one to determine the energy
barriers between two states in a bistable nematic device.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 07:08:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Harnau",
"L.",
""
],
[
"Kondrat",
"S.",
""
],
[
"Poniewierski",
"A.",
""
]
] |
0708.1997 | Antoine Suarez | Antoine Suarez | Time and nonlocal realism: Consequences of the before-before experiment | 4 pages, 1 figure | null | null | null | quant-ph | null | It is argued that recent experiments refuting nonlocal realism, can also be
considered as experiments refuting time-ordered nonlocality and, hence,
confirming the result of the before-before experiment. However, the
before-before experiment provides a broader refutation because it also
falsifies the testable relativistic version of Bohm's nonlocal model. All this
stresses the interest of a new before-before experiment demonstrating together
the failure of time-ordered nonlocality and the violation of the Leggett's
inequality.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 07:30:22 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Suarez",
"Antoine",
""
]
] |
0708.1998 | Giovanni Catanzaro Dr. | G. Catanzaro, F. Leone, I. Busa', P. Romano | Spectroscopy of the hot pulsating star Beta Cephei. Velocities and EWs
from C,N,O and Si lines | 10 pages, 5 figures, to be published in New Astronomy | New Astron.13:113-117,2008 | 10.1016/j.newast.2007.07.005 | null | astro-ph | null | Frequencies in oscillating $\beta$ Cephei stars are usually inferred by means
of radial velocities measured from the SiIII triplet 4552-4574 A. These lines,
relatively insensitive to the variation of Teff through a pulsation cycle, show
small equivalent width variations. In this study we aimed to verify if the
behavior of radial velocities and equivalent widths measured from other ions
are compatible with the one observed from SiIII lines and than to verify the
possible vertical stratification along the stellar atmosphere. For this reason
we selected from our spectra a number of, unblended and well isolated, CII, NII
and OII lines besides the famous SiIII triplet. All those lines cover the range
in optical depth between -2.1 and -0.5. Unfortunately, we did not find any
differences in the radial velocities behavior line-by-line and then we derived
the frequency of the principal radial mode combining all the velocities derived
from each spectral line separately. The inferred frequency was
f1=5.249677+/-0.000007 c/d.
Another important task we would like to accomplish with this paper is to make
available to the community our large sample of spectroscopic data, that is 932
velocities and equivalent widths measured from our sample of C, N, O and Si
lines. All the spectra were acquired at the 1-meter class telescope of the
stellar station of the INAF - Osservatorio Astrofisico di Catania, in the
period starting from July, the 27th 2005 to November, the 1st 2006.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:14:46 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Catanzaro",
"G.",
""
],
[
"Leone",
"F.",
""
],
[
"Busa'",
"I.",
""
],
[
"Romano",
"P.",
""
]
] |
0708.1999 | Beniamino Cappelletti Montano | Beniamino Cappelletti Montano | Bi-Legendrian manifolds and paracontact geometry | to appear in Int. J. Geom. Meth. Mod. Phys | Int. J. Geom. Meth. Mod. Phys. 20 (2009), 1081-1105 | 10.1142/S0129167X09005662 | null | math.DG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the interplays between paracontact geometry and the theory of
bi-Legendrian manifolds. We interpret the bi-Legendrian connection of a
bi-Legendrian manifold M as the paracontact connection of a canonical
paracontact structure induced on M and then we discuss many consequences of
this result both for bi-Legendrian and for paracontact manifolds. Finally new
classes of examples of paracontact manifolds are presented.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:17:34 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 16:28:29 GMT"
},
{
"version": "v3",
"created": "Sun, 26 Aug 2007 09:17:22 GMT"
},
{
"version": "v4",
"created": "Sun, 18 Nov 2007 19:55:40 GMT"
},
{
"version": "v5",
"created": "Sat, 24 Jan 2009 12:16:32 GMT"
}
] | 2013-06-18T00:00:00 | [
[
"Montano",
"Beniamino Cappelletti",
""
]
] |
0708.2000 | Franco Buccella | F. Buccella, D. Falcone, L. Oliver | Leptogenesis within a generalized quark-lepton symmetry | 12 pages, RevTex4. Title and abstract changed. Revised and enlarged
version | Phys.Rev.D77:033002,2008 | 10.1103/PhysRevD.77.033002 | null | hep-ph | null | Quark-lepton symmetry has been shown to be inconsistent with baryogenesis via
leptogenesis in natural schemes of the see-saw mechanism. Within the
phenomenological approach of textures, we relax this strict symmetry and
propose weaker conditions, namely models of the neutrino Dirac mass matrix
$M_D$ which have the same hierarchy as the matrix elements of $M_u$. We call
this guide-line generalized $hierarchical$ quark-lepton symmetry. We consider
in detail particular cases in which the moduli of the matrix elements of $M_D$
are equal to those of $M_u$. Within the phenomenological approach of textures,
we try for the heavy Majorana mass matrix diagonal and off-diagonal forms. We
find that an ansatz for $M_D$ preserving the hierarchy, together with an
off-diagonal model for the heavy Majorana neutrino mass, is consistent with
neutrino masses, neutrino mixing and baryogenesis via leptogenesis for an
intermediate mass scale $m_R \sim 10^{12}$ GeV. The preservation of the
hierarchical structure could come from a possible symmetry scheme.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:18:44 GMT"
},
{
"version": "v2",
"created": "Thu, 25 Oct 2007 11:58:17 GMT"
},
{
"version": "v3",
"created": "Fri, 26 Oct 2007 07:31:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Buccella",
"F.",
""
],
[
"Falcone",
"D.",
""
],
[
"Oliver",
"L.",
""
]
] |
0708.2001 | Niels Asger Mortensen | Martin H. Sorensen, Niels Asger Mortensen and Mads Brandbyge | Screening model for nanowire surface-charge sensors in liquid | 4 pages including 2 figures. Accepted for APL | Appl. Phys. Lett. 91, 102105 (2007). | 10.1063/1.2779930 | null | cond-mat.soft cond-mat.mes-hall | null | The conductance change of nanowire field-effect transistors is considered a
highly sensitive probe for surface charge. However, Debye screening of relevant
physiological liquid environments challenge device performance due to competing
screening from the ionic liquid and nanowire charge carriers. We discuss this
effect within Thomas-Fermi and Debye-Huckel theory and derive analytical
results for cylindrical wires which can be used to estimate the sensitivity of
nanowire surface-charge sensors. We study the interplay between the nanowire
radius, the Thomas-Fermi and Debye screening lengths, and the length of the
functionalization molecules. The analytical results are compared to
finite-element calculations on a realistic geometry.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:23:54 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Aug 2007 06:27:54 GMT"
}
] | 2007-09-05T00:00:00 | [
[
"Sorensen",
"Martin H.",
""
],
[
"Mortensen",
"Niels Asger",
""
],
[
"Brandbyge",
"Mads",
""
]
] |
0708.2002 | Tadayuki Takahashi | Tadayuki Takahashi, Takaaki Tanaka, Yasunobu Uchiyama, Junko S.
Hiraga, Kazuhiro Nakazawa, Shin Watanabe, Aya Bamba, John P. Hughes, Hideaki
Katagiri, Jun Kataoka, Motohide Kokubun, Katsuji Koyama, Koji Mori, Robert
Petre, Hiromitsu Takahashi, Yoko Tsuboi | Measuring the Broad-band X-Ray Spectrum from 400 eV to 40 keV in the
Southwest Part of the Supernova Remnant RX J1713.7-3946 | 11 pages, 11 figures, accepted for publication in Publications of the
Astronomical Society of Japan (PASJ) | null | 10.1093/pasj/60.sp1.S131 | null | astro-ph | null | We report on results from Suzaku broadband X-ray observations of the
southwest part of the Galactic supernova remnant (SNR) RX J1713.7-3946 with an
energy coverage of 0.4-40 keV. The X-ray spectrum, presumably of synchrotron
origin, is known to be completely lineless, making this SNR ideally suited for
a detailed study of the X-ray spectral shape formed through efficient particle
acceleration at high speed shocks. With a sensitive hard X-ray measurement from
the HXD PIN on board Suzaku, we determine the hard X-ray spectrum in the 12--40
keV range to be described by a power law with photon index Gamma = 3.2+/- 0.2,
significantly steeper than the soft X-ray index of Gamma = 2.4+/- 0.05 measured
previously with ASCA and other missions. We find that a simple power law fails
to describe the full spectral range of 0.4-40 keV and instead a power-law with
an exponential cutoff with hard index Gamma = 1.50+/- 0.09 and high-energy
cutoff epsilon_c = 1.2+/- 0.3 keV formally provides an excellent fit over the
full bandpass. If we use the so-called SRCUT model, as an alternative model, it
gives the best-fit rolloff energy of epsilon_{roll} = 0.95+/- 0.04 keV.
Together with the TeV gamma-ray spectrum ranging from 0.3 to 100 TeV obtained
recently by HESS observations, our Suzaku observations of RX J1713.7-3946
provide stringent constraints on the highest energy particles accelerated in a
supernova shock.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:14:43 GMT"
}
] | 2017-01-18T00:00:00 | [
[
"Takahashi",
"Tadayuki",
""
],
[
"Tanaka",
"Takaaki",
""
],
[
"Uchiyama",
"Yasunobu",
""
],
[
"Hiraga",
"Junko S.",
""
],
[
"Nakazawa",
"Kazuhiro",
""
],
[
"Watanabe",
"Shin",
""
],
[
"Bamba",
"Aya",
""
],
[
"Hughes",
"John P.",
""
],
[
"Katagiri",
"Hideaki",
""
],
[
"Kataoka",
"Jun",
""
],
[
"Kokubun",
"Motohide",
""
],
[
"Koyama",
"Katsuji",
""
],
[
"Mori",
"Koji",
""
],
[
"Petre",
"Robert",
""
],
[
"Takahashi",
"Hiromitsu",
""
],
[
"Tsuboi",
"Yoko",
""
]
] |
0708.2003 | Rugang Ye | Rugang Ye | The logarithmic Sobolev inequality along the Ricci flow in dimension 2 | 11 pages | null | null | null | math.DG | null | In this paper we present our results on the logarithmic Sobolev inequality
along the Ricci flow in dimension 2.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:03:51 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Ye",
"Rugang",
""
]
] |
0708.2004 | Richard Woodard | N. C. Tsamis (University of Crete) and R. P. Woodard (University of
Florida) | Reply to `Can infrared gravitons screen $\Lambda$?' | 17 pages, no figures, uses LaTeX 2epsilon. Version 2 adds important
points about R_ren being neither finite nor constant, and that a constant
Ricci scalar is not even classically an indicator of de Sitter expansion.
Version 3 corrects some typoes and updates the references | Phys.Rev.D78:028501,2008 | 10.1103/PhysRevD.78.028501 | UFIFT-QG-07-02 | hep-th astro-ph gr-qc | null | We reply to the recent criticism by Garriga and Tanaka of our proposal that
quantum gravitational loop corrections may lead to a secular screening of the
effective cosmological constant. Their argument rests upon a renormalization
scheme in which the composite operator $(R \sqrt{-g} - 4 \Lambda \sqrt{-g}
)_{\rm ren}$ is defined to be the trace of the renormalized field equations.
Although this is a peculiar prescription, we show that it {\it does not
preclude secular screening}. Moreover, we show that a constant Ricci scalar
{\it does not even classically} imply a constant expansion rate. Other
important points are: (1) the quantity $R_{\rm ren}$ of Garriga and Tanaka is
neither a properly defined composite operator, nor is it constant; (2) gauge
dependence does not render a Green's function devoid of physical content; (3)
scalar models on a non-dynamical de Sitter background (for which there is no
gauge issue) can induce arbitrarily large secular contributions to the stress
tensor; (4) the same secular corrections appear in observable quantities in
quantum gravity; and (5) the prospects seem good for deriving a simple
stochastic formulation of quantum gravity in which the leading secular effects
can be summed and for which the expectation values of even complicated, gauge
invariant operators can be computed at leading order.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:42:16 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 13:28:34 GMT"
},
{
"version": "v3",
"created": "Wed, 6 Feb 2008 18:06:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Tsamis",
"N. C.",
"",
"University of Crete"
],
[
"Woodard",
"R. P.",
"",
"University of\n Florida"
]
] |
0708.2005 | Rugang Ye | Rugang Ye | The logarithmic Sobolev inequality along the Ricci flow: the case
$\lambda_0(g_0)=0$ | 6 pages | null | null | null | math.DG | null | We extend our previous results on the logarithmic Sobolev inequality along
the Ricci flow in the case $\lambda_0(g_0)>0$ to the case $\lambda_0(g_0)=0$.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:47:57 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Ye",
"Rugang",
""
]
] |
0708.2006 | Cheng-Chin Chiang | BELLE Collaboration: K. Abe, et al | Search for B0 -> rho0rho0 and Non-Resonant B0 -> 4pi Decays | 14 pages, 5 figures, submitted to LP2007 | null | null | BELLE-CONF-0747 | hep-ex | null | We search for the decay B0 -> rho0rho0 and other possible charmless modes
with a pi+pi-pi+pi- final state, including B0 -> rho0f0(980), B0 ->
f0(980)f0(980), B0 -> f0(980)pipi, B0 -> rho0pipi and non-resonant B0 -> 4pi.
These results are obtained from a data sample containing 520 x 10^6 BBar pairs
collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We
measure a branching fraction of (0.9 +/- 0.4^{+0.3}_{-0.4}) x 10^{-6}, or B(B0
-> rho0rho0) < 1.6 x 10^{-6} at the 90% confidence level. The significance
including systematic uncertainties is 1.8\sigma. These values correspond to the
final state being longitudinally polarized. We also measure the branching
fraction of non-resonant B0 -> 4pi decay to be (10.2 +/- 4.7^{+2.3}_{-1.5}) x
10^{-6} with 2.1\sigma significance, and set the 90% confidence level upper
limit B(B0 -> 4pi) < 17.3 x 10^{-6}. For the other related decays, B0 ->
rho0f0(980), B0 -> f0(980)f0(980), B0 -> f0(980)pipi and B0 -> rho0pipi, no
significant signals are observed and upper limits on the branching fractions
are set.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:01:52 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"BELLE Collaboration",
"",
""
],
[
"Abe",
"K.",
""
]
] |
0708.2007 | Elsayed Lashin Dr. | H. A. Alhendi, E. I. Lashin and A. A. Mudlej | Textures with two traceless submatrices of the neutrino mass matrix | 17 pages, 3 figures and 2 tables, Minor typos are corrected | Phys.Rev.D77:013009,2008 | 10.1103/PhysRevD.77.013009 | null | hep-ph | null | We propose a new texture for the light neutrino mass matrix. The proposal is
based upon imposing zero-trace condition on the two by two sub-matrices of the
complex symmetric Majorana mass matrix in the flavor basis where the charged
lepton mass matrix is diagonal. Restricting the mass matrix to have two
traceless sub-matrices may be found sufficient to describe the current data.
Eight out of fifteen independent possible cases are found to be compatible with
current data. Numerical and some approximate analytical results are presented.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:53:06 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Feb 2008 21:50:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Alhendi",
"H. A.",
""
],
[
"Lashin",
"E. I.",
""
],
[
"Mudlej",
"A. A.",
""
]
] |
0708.2008 | Rugang Ye | Rugang Ye | The Log Entropy Functional Along the Ricci Flow | A typo in the monotonicity inequality for the log entropy functional
is corrected. Namely the factor 1/(16 \omega) should be (4 \omega)/n. (From
the given computations it is obvious that this number should be (4\omega)/n.) | null | null | null | math.DG | null | In this paper we introduce the log entropy functional and establish its
monotonicity along the Ricci flow. One consequence of it is the monotonicity of
the logarithmic Sobolev constant along the Ricci flow.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:57:36 GMT"
},
{
"version": "v2",
"created": "Sun, 16 Sep 2007 21:59:41 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Dec 2007 13:36:15 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Ye",
"Rugang",
""
]
] |
0708.2009 | Paul Eastham | P. R. Eastham, R. T. Phillips | Quantum condensation from a tailored exciton population in a microcavity | 5 pages, 3 figures. Version 2 is extensively rewritten, and
incorporates some new results in further support of our claims | Phys. Rev. B 79, 165303 (2009) | 10.1103/PhysRevB.79.165303 | null | cond-mat.str-el cond-mat.supr-con | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An experiment is proposed, on the coherent quantum dynamics of a
semiconductor microcavity containing quantum dots. Modeling the experiment
using a generalized Dicke model, we show that a tailored excitation pulse can
create an energy-dependent population of excitons, which subsequently evolves
to a quantum condensate of excitons and photons. The population is created by a
generalization of adiabatic rapid passage, and then condenses due to a
dynamical analog of the BCS instability.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 08:58:03 GMT"
},
{
"version": "v2",
"created": "Mon, 28 Jul 2008 10:33:54 GMT"
}
] | 2009-04-08T00:00:00 | [
[
"Eastham",
"P. R.",
""
],
[
"Phillips",
"R. T.",
""
]
] |
0708.2010 | Soeren Frandsen | S. Frandsen, H. Bruntt, F. Grundahl, G. Kopacki, H. Kjeldsen, T.
Arentoft, D. Stello, T. R. Bedding, A. P. Jacob, R. L. Gilliland, P. D.
Edmonds, E. Michel, J. Matthiesen | A search for solar-like oscillations in K giants in the globular cluster
M4 | 14 pages, 16 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20078267 | null | astro-ph | null | To expand the range in the colour-magnitude diagram where asteroseismology
can be applied, we organized a photometry campaign to find evidence for
solar-like oscillations in giant stars in the globular cluster M4. The aim was
to detect the comb-like p-mode structure characteristic for solar-like
oscillations in the amplitude spectra. The two dozen main target stars are in
the region of the bump stars and have luminosities in the range 50-140 Lsun. We
collected 6160 CCD frames and light curves for about 14000 stars were
extracted. We obtain high quality light curves for the K giants, but no clear
oscillation signal is detected. High precision differential photometry is
possible even in very crowded regions like the core of M4. Solar-like
oscillations are probably present in K giants, but the amplitudes are lower
than classical scaling laws predict.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:14:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Frandsen",
"S.",
""
],
[
"Bruntt",
"H.",
""
],
[
"Grundahl",
"F.",
""
],
[
"Kopacki",
"G.",
""
],
[
"Kjeldsen",
"H.",
""
],
[
"Arentoft",
"T.",
""
],
[
"Stello",
"D.",
""
],
[
"Bedding",
"T. R.",
""
],
[
"Jacob",
"A. P.",
""
],
[
"Gilliland",
"R. L.",
""
],
[
"Edmonds",
"P. D.",
""
],
[
"Michel",
"E.",
""
],
[
"Matthiesen",
"J.",
""
]
] |
0708.2011 | Sebastian Herr | Martin Hadac, Sebastian Herr, Herbert Koch | Well-posedness and scattering for the KP-II equation in a critical space | 28 pages; v3: erratum included | Ann. I. H. Poincare - AN (2009), Vol. 26, No. 3, pp. 917-941;
Erratum: Ann. I. H. Poincare - AN (2010), Vol. 27, No. 3, pp. 971-972 | 10.1016/j.anihpc.2008.04.002 10.1016/j.anihpc.2010.01.006 | null | math.AP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Cauchy problem for the Kadomtsev-Petviashvili-II equation
(u_t+u_{xxx}+uu_x)_x+u_{yy}=0 is considered. A small data global well-posedness
and scattering result in the scale invariant, non-isotropic, homogeneous
Sobolev space \dot H^{-1/2,0}(R^2) is derived. Additionally, it is proved that
for arbitrarily large initial data the Cauchy problem is locally well-posed in
the homogeneous space \dot H^{-1/2,0}(R^2) and in the inhomogeneous space
H^{-1/2,0}(R^2), respectively.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:59:22 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Sep 2007 14:42:13 GMT"
},
{
"version": "v3",
"created": "Wed, 23 Dec 2009 16:41:34 GMT"
}
] | 2010-11-03T00:00:00 | [
[
"Hadac",
"Martin",
""
],
[
"Herr",
"Sebastian",
""
],
[
"Koch",
"Herbert",
""
]
] |
0708.2012 | Peter D'Eath | A.N.St.J.Farley and P.D.D'Eath | Relic Radiation from an Evaporating Black Hole | To appear in International Journal of Modern Physics D | Int.J.Mod.Phys.D17:1-23,2008 | 10.1142/S0218271808010621 | null | hep-th | null | We present a non-string-theoretic calculation of the microcanonical entropy
of relic integer-spin Hawking radiation -- at fixed total energy $E$. The only
conserved macroscopic quantity is the total energy $E$ (the total energy of the
relic radiation). Data for a boundary-value approach, with massless,
integer-spin perturbations, are set on initial and final space-like
hypersurfaces. In the resulting 1-dimensional statistical-mechanics problem,
the real part of the (complex) time separation at spatial infinity, $T =
{\mid}T{\mid}\exp(-i\delta), \delta >0$, is the variable conjugate to the total
energy. We count the number of weak-field configurations on the final
space-like hypersurface with energy $E$. One recovers the Cardy formula and the
Bekenstein-Hawking entropy, if Re(T) is of the order of the black-hole life-
time, leading to a statistical interpretation of black-hole entropy. The
microcanonical entropy includes a logarithmic correction to the black-hole area
law, which is {\it universal} (independent of black-hole parameters). Here, the
discreteness of the energy levels is crucial. This approach is compared with
that of string theory for the transition to the fundamental-string r\'egime in
the final stages of evaporation. The squared coupling, $g^2$, regulating the
transition to a highly-excited string state and {\it vice versa}, can be
related to the angle, $\delta$, of complex-time rotation above. The
strong-coupling r\'egime corresponds to a Euclidean black hole, while the
physical limit of a Lorentzian space-time (as $ \delta \to 0_+$) corresponds to
the weak-coupling r\'egime. This resembles the transition to a highly-excited
string-like state which subsequently decays into massless particles, thereby
avoiding the naked singularity.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:20:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Farley",
"A. N. St. J.",
""
],
[
"D'Eath",
"P. D.",
""
]
] |
0708.2013 | Peter D'Eath | A.N.St.J.Farley, P.D. D'Eath | Quantum amplitudes in black-hole evaporation: Spins 1 and 2 | null | AnnalsPhys.321:1334-1374,2006 | 10.1016/j.aop.2005.11.011 | null | gr-qc | null | Quantum amplitudes for $s=1$ at Maxwell fields and for $s=2$ linearised
gravitational wave perturbations of a spherically symmetric Einstein/massless
scalar background, describing gravitational collapse to a black hole, are
treated by analogy with a previous treatment of $s=0$ scalar-field
perturbations of gravitational collapse at late times. In both the $s=1$ and
$s=2$ cases, we isolate suitable 'co-ordinate' variables which can be taken as
boundary data on a final space-like hypersurface $\Sigma_F$. For simplicity, we
take the data on an initial pre-collapse surface $\Sigma_I$ to be exactly
spherically symmetric. The (large) Lorentzian proper-time interval between
$\Sigma_{I}, \Sigma_{F}$, measured at spatial infinity, is denoted by $T$. The
complexified classical boundary-value problem is expected to be well-posed,
provide that the time interval $T$ has been rotated into the complex:
$T\to{\mid}T{\mid}\exp(-i\theta)$, for $0<\theta\leq{\pi}/2$. We calculate the
second-variation classical Lorenztian action $S ^{(2)}_{\rm class}$. Following
Feynman, we recover the Lorentzian quantum amplitude by taking the limit as
$\theta\to 0_+$ of the semi-classical amplitude $\exp(iS^{(2)}_{\rm class})$.
The boundary data for $ s=1$ involve the Maxwell magnetic field; the data for
$s=2$ involve the magnetic part of the Weyl curvature tensor. The magnetic
boundary conditions are related to each other and to the natural $s={1 \over
2}$ boundary conditions by supersymmetry.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:38:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Farley",
"A. N. St. J.",
""
],
[
"D'Eath",
"P. D.",
""
]
] |
0708.2014 | Andrzej Kup\'s\'c Dr | M. Bashkanov, D. Bogoslawsky, H. Cal\'en, F. Capellaro, H. Clement, L.
Demir\"ors, C. Ekstr\"om, K. Fransson, L. Gustafsson, B. H\"oistad, G.
Ivanov, M. Jacewicz, E. Jiganov, T. Johansson, S. Keleta, I. Koch, S.
Kullander, A. Kupsc, A. Kuznetsov, P. Marciniewski, R. Meier, B. Morosov, W.
Oelert, C. Pauly, Y. Petukhov, H. Pettersson, A. Povtorejko, R. J. M. Y.
Ruber, K. Sch\"onning, W. Scobel, T. Skorodko, B. Shwartz, V. Sopov, J.
Stepaniak, V. Tchernyshev, P. Th\"orngren Engblom, V. Tikhomirov, A.
Turowiecki, G.J. Wagner, U. Wiedner, M. Wolke, A. Yamamoto, J. Zabierowski,
J. Z{\l}oma\'nczuk | Measurement of the Slope Parameter for the eta->3pi0 Decay in the pp->pp
eta Reaction | 4 pages, 7 Postscript figures, uses revtex4.sty | Phys.Rev.C76:048201,2007 | 10.1103/PhysRevC.76.048201 | null | nucl-ex | null | The CELSIUS/WASA setup is used to measure the 3pi0 decay of eta mesons
produced in pp interactions with beam kinetic energies of 1.36 and 1.45 GeV.
The efficiency-corrected Dalitz plot and density distributions for this decay
are shown, together with a fit of the quadratic slope parameter alpha yielding
alpha = -0.026 +/- 0.010(stat) +/- 0.010(syst). This value is compared to
recent experimental results and theoretical predictions.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 15:55:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bashkanov",
"M.",
""
],
[
"Bogoslawsky",
"D.",
""
],
[
"Calén",
"H.",
""
],
[
"Capellaro",
"F.",
""
],
[
"Clement",
"H.",
""
],
[
"Demirörs",
"L.",
""
],
[
"Ekström",
"C.",
""
],
[
"Fransson",
"K.",
""
],
[
"Gustafsson",
"L.",
""
],
[
"Höistad",
"B.",
""
],
[
"Ivanov",
"G.",
""
],
[
"Jacewicz",
"M.",
""
],
[
"Jiganov",
"E.",
""
],
[
"Johansson",
"T.",
""
],
[
"Keleta",
"S.",
""
],
[
"Koch",
"I.",
""
],
[
"Kullander",
"S.",
""
],
[
"Kupsc",
"A.",
""
],
[
"Kuznetsov",
"A.",
""
],
[
"Marciniewski",
"P.",
""
],
[
"Meier",
"R.",
""
],
[
"Morosov",
"B.",
""
],
[
"Oelert",
"W.",
""
],
[
"Pauly",
"C.",
""
],
[
"Petukhov",
"Y.",
""
],
[
"Pettersson",
"H.",
""
],
[
"Povtorejko",
"A.",
""
],
[
"Ruber",
"R. J. M. Y.",
""
],
[
"Schönning",
"K.",
""
],
[
"Scobel",
"W.",
""
],
[
"Skorodko",
"T.",
""
],
[
"Shwartz",
"B.",
""
],
[
"Sopov",
"V.",
""
],
[
"Stepaniak",
"J.",
""
],
[
"Tchernyshev",
"V.",
""
],
[
"Engblom",
"P. Thörngren",
""
],
[
"Tikhomirov",
"V.",
""
],
[
"Turowiecki",
"A.",
""
],
[
"Wagner",
"G. J.",
""
],
[
"Wiedner",
"U.",
""
],
[
"Wolke",
"M.",
""
],
[
"Yamamoto",
"A.",
""
],
[
"Zabierowski",
"J.",
""
],
[
"Złomańczuk",
"J.",
""
]
] |
0708.2015 | Magd Elias Kahil | M. E. Kahil | Motion in Brane World Models: The Bazanski Approach | A paper presented at the Thirteenth International Symposium on
Particles, Strings and Cosmology PASCOS-07, held in London, 2-7 July 2007 | AIPConf.Proc.957:329-332,2007 | 10.1063/1.2823794 | null | gr-qc hep-th | null | Recently, path equations have been obtained for charged, spinning objects in
brane world models, using a modified Bazanski Lagrangian. In this study, path
deviation equations of extended objects are derived. The significance of moving
extended objects in brane world models is examined. Motion in non- symmetric
brane world models is also considered.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:10:34 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 14:03:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kahil",
"M. E.",
""
]
] |
0708.2016 | Yasuhiro Okada | Yasuhiro Okada | Higgs Particle: The Origin of Mass | 13 pages, 4 figures, to appear in Special Topics Issue of J. Phys.
Soc. Jpn | J.Phys.Soc.Jap.76:111011,2007 | 10.1143/JPSJ.76.111011 | KEK-TH-1171 | hep-ph | null | The Higgs particle is a new elementary particle predicted in the Standard
Model of the elementary particle physics. It plays a special role in the theory
of mass generation of quarks, leptons, and gauge bosons. In this article,
theoretical issues on the Higgs mechanism are first discussed, and then
experimental prospects on the Higgs particle study at the future collider
experiments, LHC and ILC, are reviewed. The Higgs coupling determination is an
essential step to establish the mass generation mechanism, which could lead to
a deeper understanding of particle physics.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:50:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Okada",
"Yasuhiro",
""
]
] |
0708.2017 | Stephan Kummel | Michael Mundt and Stephan K\"ummel | Photoelectron spectra of anionic sodium clusters from time-dependent
density-functional theory in real-time | null | Physical Review B 76, 035413 (2007) | 10.1103/PhysRevB.76.035413 | null | cond-mat.mtrl-sci | null | We calculate the excitation energies of small neutral sodium clusters in the
framework of time-dependent density-functional theory. In the presented
calculations, we extract these energies from the power spectra of the dipole
and quadrupole signals that result from a real-time and real-space propagation.
For comparison with measured photoelectron spectra, we use the ionic
configurations of the corresponding single-charged anions. Our calculations
clearly improve on earlier results for photoelectron spectra obtained from
static Kohn-Sham eigenvalues.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:28:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mundt",
"Michael",
""
],
[
"Kümmel",
"Stephan",
""
]
] |
0708.2018 | Peter D'Eath | A.N.St.J.Farley, P.D.D'Eath | Quantum amplitudes in black-hole evaporation: coherent and squeezed
states | null | Class.Quant.Grav.24:105-127,2007 | 10.1088/0264-9381/24/1/006 | null | gr-qc | null | The quantum amplitude for processes involving the formation and evaporation
of black holes was previously calculated by means of a complex-time approach.
In that treatment, we followed Feynman's $+i\epsilon$ approach in quantum field
theory. The Lorentzian time interval $T$, measured at spatial infinity between
a pair of asymptotically flat spacelike hypersurfaces $\Sigma_I$ and $\Sigma_F$
carrying initial and final boundary data for the gravitational and other
fields, is rotated: $T\to{\mid}T{\mid}\exp(-i\delta)$, where $0< \delta
\leq{\pi}/2$. Classically and quantum mechanically, this procedure is expected
to lead to a well-posed boundary-value problem. Thus, we have found quantum
amplitudes (not just probability densities) relating to a pure state at late
times following gravitational collapse of matter to a black hole. Such pure
states, arising from gravitational collapse, admit a description in terms of
coherent and squeezed states. Indeed, this description is not so different from
that arising in a well-known context, namely, the highly-squeezed final state
of the relic radiation background in inflationary cosmology. For definiteness,
we study the simplest model of collapse, based on Einstein gravity with a
massless scalar field. Following the complex rotation above, one finds that, in
an adiabatic approximation, the resulting quantum amplitude may be expressed in
terms of generalized coherent states of the harmonic oscillator. A physical
interpretation is given; further, a squeezed-state representation follows.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:54:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Farley",
"A. N. St. J.",
""
],
[
"D'Eath",
"P. D.",
""
]
] |
0708.2019 | Chengyong Hu | C. Y. Hu, A. Young, J. L. O'Brien and J. G. Rarity | Giant optical Faraday rotation induced by a single electron spin in a
quantum dot: Applications to entangling remote spins via a single photon | 5 pages, 3 figures | Phys. Rev. B 78, 085307 (2008) | 10.1103/PhysRevB.78.085307 | null | quant-ph cond-mat.other | null | We propose a quantum non-demolition method - giant Faraday rotation - to
detect a single electron spin in a quantum dot inside a microcavity where
negatively-charged exciton strongly couples to the cavity mode. Left- and
right-circularly polarized light reflected from the cavity feels different
phase shifts due to cavity quantum electrodynamics and the optical spin
selection rule. This yields giant and tunable Faraday rotation which can be
easily detected experimentally. Based on this spin-detection technique, a
scalable scheme to create an arbitrary amount of entanglement between two or
more remote spins via a single photon is proposed.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 09:55:57 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Mar 2008 10:52:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hu",
"C. Y.",
""
],
[
"Young",
"A.",
""
],
[
"O'Brien",
"J. L.",
""
],
[
"Rarity",
"J. G.",
""
]
] |
0708.2020 | Alberto Elices | A. Elices | Models with time-dependent parameters using transform methods:
application to Heston's model | 10 pages, 10 figures, 6 tables, error corrected in sections VI and
VII, references added in sections I and VI, Submitted to the Journal of
Mathematical Finance | null | null | null | q-fin.PR math.PR stat.ME | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper presents a methodology to introduce time-dependent parameters for
a wide family of models preserving their analytic tractability. This family
includes hybrid models with stochastic volatility, stochastic interest-rates,
jumps and their non-hybrid counterparts. The methodology is applied to Heston's
model. A bootstrapping algorithm is presented for calibration. A case study
works out the calibration of the time-dependent parameters to the volatility
surface of the Eurostoxx 50 index. The methodology is also applied to the
analytic valuation of forward start vanilla options driven by Heston's model.
This result is used to explore the forward skew of the case study.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:12:42 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Oct 2008 11:46:43 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Elices",
"A.",
""
]
] |
0708.2021 | Juan J. Merelo Pr. | Juan J. Merelo and Carlos Cotta | Who is the best connected EC researcher? Centrality analysis of the
complex network of authors in evolutionary computation | Abstract accepted as poster to the GECCO 2007 conference | null | null | null | cs.CY cs.NE | null | Co-authorship graphs (that is, the graph of authors linked by co-authorship
of papers) are complex networks, which expresses the dynamics of a complex
system. Only recently its study has started to draw interest from the EC
community, the first paper dealing with it having been published two years ago.
In this paper we will study the co-authorship network of EC at a microscopic
level. Our objective is ascertaining which are the most relevant nodes (i.e.
authors) in it. For this purpose, we examine several metrics defined in the
complex-network literature, and analyze them both in isolation and combined
within a Pareto-dominance approach. The result of our analysis indicates that
there are some well-known researchers that appear systematically in top
rankings. This also provides some hints on the social behavior of our
community.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:13:03 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Merelo",
"Juan J.",
""
],
[
"Cotta",
"Carlos",
""
]
] |
0708.2022 | Yichao Tian | Yichao Tian | p-adic Monodromy of the Universal Deformation of a HW-cyclic
Barsotti-Tate Group | 36 pages, part of the author's thesis | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let k be an algebraically closed field of characteristic $p>0$, and $G_0$ be
a Barsotti-Tate group (or $p$-divisible group) over k. We denote by $S$ the
"algebraic" local moduli in characteristic p of $G_0$, by $G$ the universal
deformation of $G_0$ over $S$, and by $U\subset S$ the ordinary locus of $G$.
The etale part of $G$ over $U$ gives rise to a monodromy representation $\rho$
of the fundamental group of $U$ on the Tate module of $G$. Motivated by a
famous theorem of Igusa, we prove in this article that $\rho$ is surjective if
$G_0$ is connected and HW-cyclic. This latter condition is equivalent to that
Oort's $a$-number of $G_0$ equals 1, and it is satisfied by all connected
one-dimensional Barsotti-Tate groups over $k$.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:43:25 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Aug 2008 21:38:29 GMT"
}
] | 2008-08-25T00:00:00 | [
[
"Tian",
"Yichao",
""
]
] |
0708.2023 | Lyubov Positselskaya | Lyubov N. Positselskaya | Nonantagonistic noisy duels of discrete type with an arbitrary number of
actions | LaTeX 2e, 22 pages; replaced to correct TeXnical mistakes and typos | null | null | null | math.OC cs.GT math.PR | null | We study a nonzero-sum game of two players which is a generalization of the
antagonistic noisy duel of discrete type. The game is considered from the point
of view of various criterions of optimality. We prove existence of
epsilon-equilibrium situations and show that the epsilon-equilibrium strategies
that we have found are epsilon-maxmin. Conditions under which the equilibrium
plays are Pareto-optimal are given.
Keywords: noisy duel, payoff function, strategy, equilibrium situation,
Pareto optimality, the value of a game.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:42:27 GMT"
},
{
"version": "v2",
"created": "Sat, 18 Aug 2007 14:17:25 GMT"
}
] | 2007-08-18T00:00:00 | [
[
"Positselskaya",
"Lyubov N.",
""
]
] |
0708.2024 | Heino Finkelmann | Dominic Kramer, Heino Finkelmann | Commentary on: "Unconventional elasticity in smectic-A elastomers" by O.
Stenull and T.C. Lubensky | 2 pages, 1 figure, Commentary on: "Unconventional elasticity in
smectic-A elastomers" by O. Stenull and T. C. Lubensky (0706.3020v1) | null | null | null | cond-mat.soft cond-mat.mtrl-sci | null | The reorientation behaviour of a smectic-A (SmA) elastomer deformed parallel
to the smectic layer normal has been interpreted as a Sm-C like transition by
Stenull and Lubensky. Experiments, however, prove that such a transition does
not occur.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:23:23 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Kramer",
"Dominic",
""
],
[
"Finkelmann",
"Heino",
""
]
] |
0708.2025 | Nam Dao | D. N. H. Nam, N. V. Dai, L. V. Hong, N. X. Phuc, L. V. Bau, P.
Nordblad and R. S. Newrock | Effects of selective dilution on the magnetic properties of
La_{0.7}Sr_{0.3}Mn_{1-x}M'_xO_3 (M' = Al, Ti) | Revtex4, 4 pages, 4 figures, 2006 Halong Conference Report | null | 10.3938/jkps.52.1460 | null | cond-mat.mtrl-sci cond-mat.str-el | null | The magnetic lattice of mixed-valence Mn ions in
La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ is selectively diluted by partial substitution of
Al or Ti for Mn. The ferromagnetic transition temperature $T_\mathrm{c}$ and
the saturation magnetization $M_\mathrm{s}$ both decrease with substitution. By
presenting the data in terms of selective dilution, $T_\mathrm{c}$ in the
low-doping region is found to follow the relation
$T_\mathrm{c}=T_\mathrm{c0}(1-n_\mathrm{p})$, where $T_\mathrm{c0}$ refers to
the undiluted system and $n_\mathrm{p}$ is the dilution concentration defined
as $n_\mathrm{p}=x/0.7$ or $n_\mathrm{p}=x/0.3$ for $M^\prime=$ Al or Ti,
respectively. The scaling behavior of $T_\mathrm{c}(n_\mathrm{p})$ can be
analyzed in the framework of the molecular-field theory and still valid when Mn
is substituted by both Al and Ti. The results are discussed with respect to the
contributions from ferromagnetic double exchange and other possible
antiferromagnetic superexchange interactions coexisting in the material.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:53:09 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Nam",
"D. N. H.",
""
],
[
"Dai",
"N. V.",
""
],
[
"Hong",
"L. V.",
""
],
[
"Phuc",
"N. X.",
""
],
[
"Bau",
"L. V.",
""
],
[
"Nordblad",
"P.",
""
],
[
"Newrock",
"R. S.",
""
]
] |
0708.2026 | Albert Guill\'en i F\`abregas | Albert Guillen I Fabregas and Alfonso Martinez | Derivative of BICM Mutual Information | submitted to the IET Electronics Letters. 4 pages, 1 figure | null | null | null | cs.IT math.IT | null | In this letter we determine the derivative of the mutual information
corresponding to bit-interleaved coded modulation systems. The derivative
follows as a linear combination of minimum-mean-squared error functions of
coded modulation sets. The result finds applications to the analysis of
communications systems in the wideband regime and to the design of power
allocation over parallel channels.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:38:01 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Fabregas",
"Albert Guillen I",
""
],
[
"Martinez",
"Alfonso",
""
]
] |
0708.2027 | Rostyslav Vlokh O | A. Say, S. Sveleba, I. Teslyuk, I. Martynyuk-Lototska, I. Girnyk and
R. Vlokh | Optical Birefringence and Domain Structure of the as-grown
Rb2xTl2(1-x)Cd2(SO4)3 Solid Solutions at Phase Transitions | 7 pages, 5 figures | Ukr. J. Phys. Opt. 2006, 7, 41-47 | 10.3116/16091833/7/1/41/2006 | null | cond-mat.other | null | It is shown that the as-grown solid solutions Tl2xRb2(1-x)Cd2(SO4)3 possess a
residual optical birefringence in the cubic phase at room temperature. The
existence of both the residual birefringence and the residual domain structure
in the compound with x=0.8 at the room temperature, along with the domain walls
orientation and the orientation of extinction positions of the neighbouring
domains, indicate that the above domain structure corresponds to "forbidden"
ferroelastic domains of the phase P212121. On the basis of measurements for the
temperature variation of the birefringence and observations of the domain
structure transformations, one can conclude that the phases with the symmetries
P213 and P21 coexist above Tc1 in the compounds with x = 0.7 - 1.0. The phase
transition temperatures Tc1, Tc2, and Tc3 obtained from the temperature
birefringence variations agree well with those obtained previously, using the
studies of thermal expansion and ultrasonic wave velocities.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:32:19 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Say",
"A.",
""
],
[
"Sveleba",
"S.",
""
],
[
"Teslyuk",
"I.",
""
],
[
"Martynyuk-Lototska",
"I.",
""
],
[
"Girnyk",
"I.",
""
],
[
"Vlokh",
"R.",
""
]
] |
0708.2028 | Rostyslav Vlokh O | O. Krupych, I. Smaga, R. Vlokh | Studies of Optical Damage in Photorefractive Single LiNbO3 Crystals
using Imaging Polarimetry | 5 pages, 6 figures | Ukr. J. Phys. Opt. 2005 6 146-149 | 10.3116/16091833/6/4/146/2005 | null | physics.gen-ph physics.optics | null | The optical damage of photorefractive material, single LiNbO3 crystal, is
experimentally studied. The specimen has been illuminated with the radiation of
continuous Ar-laser (the wavelength of 488 nm) focused to 35?m spot. The
induced birefringence map is obtained by means of imaging polarimeter.
Promising resources of the experimental setup for detecting laser-induced
damage in photorefractive materials is demonstrated.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:42:37 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Krupych",
"O.",
""
],
[
"Smaga",
"I.",
""
],
[
"Vlokh",
"R.",
""
]
] |
0708.2029 | Cheikh Ndiaye birahim | Cheikh Birahim Ndiaye | Curvature flows on four manifolds with boundary | null | null | null | null | math.AP math.DG | null | Given a compact four dimensional smooth Riemannian manifold $(M,g)$ with
smooth boundary, we consider the evolution equation by $Q$-curvature in the
interior keeping the $T$-curvature and the mean curvature to be zero and the
evolution equation by $T$-curvature at the boundary with the condition that the
$Q$-curvature and the mean curvature vanish. Using integral method, we prove
global existence and convergence for the $Q$-curvature flow (resp $T$-curvature
flow) to smooth metric of prescribed $Q$-curvature (resp
$T$-curvature) under conformally invariant assumptions.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:00:20 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Ndiaye",
"Cheikh Birahim",
""
]
] |
0708.2030 | Lucia Popa | L. A. Popa and A. Vasile (Institute for Space Sciences, Bucharest,
Romania) | Constraints on non-thermal Dark Matter from Planck lensing extraction | 15 pages, 6 figures | JCAP 0710:017,2007 | 10.1088/1475-7516/2007/10/017 | null | astro-ph | null | Distortions of CMB temperature and polarization anisotropy maps caused by
gravitational lensing, observable with high angular resolution and sensitivity,
can be used to constrain the sterile neutrino mass, offering several advantages
against the analysis based on the combination of CMB, LSS and Ly\alpha forest
power spectra. As the gravitational lensing effect depends on the matter
distribution, no assumption on light-to-mass bias is required. In addition,
unlike the galaxy clustering and Ly\alpha forest power spectra, the projected
gravitational potential power spectrum probes a larger range of angular scales,
the non-linear corrections being required only at very small scales. Taking
into account the changes in the time-temperature relation of the primordial
plasma and the modification of the neutrino thermal potential, we compute the
projected gravitational potential power spectrum and its correlation with the
temperature in the presence of DM sterile neutrino. We show that the
cosmological parameters are generally not biased when DM sterile neutrino is
included. From this analysis we found a lower limit on DM sterile neutrino mass
m_s >2.08 keV at 95% CL, consistent with the lower mass limit obtained from the
combined analysis of CMB, SDSS 3D power spectrum and SDSS Ly\alpha forest power
spectrum ($m_{\nu_s}>1.7$ keV). We conclude that although the information that
can be obtained from lensing extraction is rather limited due to the high level
of the lensing noise of Planck experiment, weak lensing of CMB offers a
valuable alternative to constrain the dark matter sterile neutrino mass.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:37:42 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Popa",
"L. A.",
"",
"Institute for Space Sciences, Bucharest,\n Romania"
],
[
"Vasile",
"A.",
"",
"Institute for Space Sciences, Bucharest,\n Romania"
]
] |
0708.2031 | Simon Pustilnik | Simon A. Pustilnik (Special Astrophysical Observatory RAS) | "Dark galaxies" and local very metal-poor gas-rich galaxies: possible
interrelations | 5 pages, no figures, to be published in Proc. of IAUS 244 "Dark
Galaxies and Lost Baryons". Improved English, references updated | null | 10.1017/S1743921307014196 | null | astro-ph | null | There are only a few ``dark galaxy'' candidates discovered to date in the
local Universe. One of the most prominent of them is the SW component of a
merging system HI 1225+01. On the other hand, the number of known very
metal-poor gas-rich dwarfs similar to IZw18 and SBS 0335-052 E,W has grown
drastically during the last decade, from a dozen and a half to about five
dozen. Many of them are very gas-rich, having from ~90 to 99% of all baryons in
gas. For some of such objects that have the deep photometry data, no evidences
for the light of old stars are found. At least a half of such galaxies with the
prominent starbursts have various evidences of interactions, including advanced
mergers. This suggests that a fraction of this group objects can be a kind of
very stable protogalaxies (or ``dark galaxies''), which have recently
experienced strong disturbances from nearby massive galaxy-size bodies. Such a
collision caused the gas instabilities and its collapse with the subsequent
onset of starburst. We briefly discuss the morphology and gas kinematics for
the subsample of the most metal-poor dwarfs that illustrate this picture. We
discuss also the relation of these rare galaxies to the processes by which
``dark galaxies'' can occasionally transform to optically visible galaxies.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:50:48 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Sep 2007 07:07:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pustilnik",
"Simon A.",
"",
"Special Astrophysical Observatory RAS"
]
] |
0708.2032 | Thomas Heinzel | S. Hugger, M. Cerchez, H. Xu and T. Heinzel | Influence of magnetic field offsets on the resistance of magnetic
barriers in two-dimensional electron gases | 6 pages, 5 figures | Phys. Rev. B 76, 195308 (2007) | 10.1103/PhysRevB.76.195308 | null | cond-mat.mes-hall | null | Magnetic barriers in two-dimensional electron gases are shifted in B space by
homogeneous, perpendicular magnetic fields. The magnetoresistance across the
barrier shows a characteristic asymmetric dip in the regime where the polarity
of the homogeneous magnetic field is opposite to that one of the magnetic
barrier. The measurements are in quantitative agreement with semiclassical
simulations, which reveal that the magnetoresistance originates from the
interplay of snake orbits with E x B drift at the edges of the Hall bar and
with elastic scattering.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 11:56:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hugger",
"S.",
""
],
[
"Cerchez",
"M.",
""
],
[
"Xu",
"H.",
""
],
[
"Heinzel",
"T.",
""
]
] |
0708.2033 | Alexei P. Martynenko | A. P. Martynenko | Ground-state triply and doubly heavy baryons in a relativistic
three-quark model | 10 pages, 2 figures, LaTex | Phys.Lett.B663:317-321,2008 | 10.1016/j.physletb.2008.04.030 | SSU-HEP-07/8 | hep-ph | null | Mass spectra of the ground-state baryons consisting of three or two heavy (b
or c) and one light (u,d,s) quarks are calculated in the framework of the
relativistic quark model and the hyperspherical expansion. The predictions of
masses of the triply and doubly heavy baryons are obtained by employing the
perturbation theory for the spin-independent and spin-dependent parts of the
three-quark Hamiltonian.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:00:14 GMT"
},
{
"version": "v2",
"created": "Wed, 22 Aug 2007 11:15:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Martynenko",
"A. P.",
""
]
] |
0708.2034 | Rebecca Martin | Rebecca G. Martin, J. E. Pringle and Christopher A. Tout | Alignment and Precession of a Black Hole with a Warped Accretion Disc | Accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12349.x | null | astro-ph | null | We consider the shape of an accretion disc whose outer regions are misaligned
with the spin axis of a central black hole and calculate the steady state form
of the warped disc in the case where the viscosity and surface densities are
power laws in the distance from the central black hole. We discuss the shape of
the resulting disc in both the frame of the black hole and that of the outer
disc. We note that some parts of the disc and also any companion star maybe
shadowed from the central regions by the warp. We compute the torque on the
black hole caused by the Lense-Thirring precession and hence compute the
alignment and precession timescales. We generalise the case with viscosity and
hence surface density independent of radius to more realistic density
distributions for which the surface density is a decreasing function of radius.
We find that the alignment timescale does not change greatly but the precession
timescale is more sensitive. We also determine the effect on this timescale if
we truncate the disc. For a given truncation radius, the the timescales are
less affected for more sharply falling density distributions.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:06:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Martin",
"Rebecca G.",
""
],
[
"Pringle",
"J. E.",
""
],
[
"Tout",
"Christopher A.",
""
]
] |
0708.2035 | Rostyslav Vlokh O | I. Martynyuk-Lototska, T. Dudok, O. Krupych, V. Adamiv, Ye. Smirnov,
R. Vlokh | Acoustooptic Diffraction in Borate Crystals | 4 pages, 5 figures | Ukr. J. Phys. Opt. 2004 5 111-114 | 10.3116/16091833/5/4/111/2004 | null | physics.gen-ph physics.optics | null | The efficiency of acoustooptic (AO) diffraction in a-BaB2O4 and Li2B4O7
crystals is studied experimentally. The crystals are shown to be quite good AO
materials. The efficiency of AO diffraction in a-BaB2O4 reaches h=30% at the
electric signal power of P=0.7W for the transverse acoustic wave and 15% at the
power of P=0.56W for the longitudinal wave. The same parameter for Li2B4O7
reaches h=21% at P=0,81W for the longitudinal acoustic wave.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:14:49 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Martynyuk-Lototska",
"I.",
""
],
[
"Dudok",
"T.",
""
],
[
"Krupych",
"O.",
""
],
[
"Adamiv",
"V.",
""
],
[
"Smirnov",
"Ye.",
""
],
[
"Vlokh",
"R.",
""
]
] |
0708.2036 | Taro Nagao | Taro Nagao | Pfaffian Expressions for Random Matrix Correlation Functions | 28 pages | J. Stat. Phys. 129 (2007) 1137 | 10.1007/s10955-007-9415-9 | null | math-ph math.MP | null | It is well known that Pfaffian formulas for eigenvalue correlations are
useful in the analysis of real and quaternion random matrices. Moreover the
parametric correlations in the crossover to complex random matrices are
evaluated in the forms of Pfaffians. In this article, we review the
formulations and applications of Pfaffian formulas. For that purpose, we first
present the general Pfaffian expressions in terms of the corresponding skew
orthogonal polynomials. Then we clarify the relation to Eynard and Mehta's
determinant formula for hermitian matrix models and explain how the evaluation
is simplified in the cases related to the classical orthogonal polynomials.
Applications of Pfaffian formulas to random matrix theory and other fields are
also mentioned.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:15:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Nagao",
"Taro",
""
]
] |
0708.2037 | Matthew Corne | Matthew Corne, Arkady Kheyfets, Warner Miller | Non--Localizability of Electric Coupling and Gravitational Binding of
Charged Objects | 7 pages, no figures | Class.Quant.Grav.24:5999-6006,2007 | 10.1088/0264-9381/24/23/019 | null | gr-qc | null | The energy--momentum tensor in general relativity contains only localized
contributions to the total energy--momentum. Here, we consider a static,
spherically symmetric object consisting of a charged perfect fluid. For this
object, the total gravitational mass contains a non--localizable contribution
of electric coupling (ordinarily associated with electromagnetic mass). We
derive an explicit expression for the total mass which implies that the
non--localizable contribution of electric coupling is not bound together by
gravity, thus ruling out existence of the objects with pure Lorentz
electromagnetic mass in general relativity.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 12:47:45 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Jan 2008 01:37:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Corne",
"Matthew",
""
],
[
"Kheyfets",
"Arkady",
""
],
[
"Miller",
"Warner",
""
]
] |
0708.2038 | Julius Lucks | Julius B. Lucks, David R. Nelson, Grzegorz Kudla, Joshua B. Plotkin | Genome landscapes and bacteriophage codon usage | 9 Color Figures, 5 Tables, 53 References | Lucks JB, Nelson DR, Kudla GR, Plotkin JB (2008) Genome Landscapes
and Bacteriophage Codon Usage. PLoS Computational Biology 4(2): e1000001 | 10.1371/journal.pcbi.1000001 | null | q-bio.GN | null | Across all kingdoms of biological life, protein-coding genes exhibit unequal
usage of synonmous codons. Although alternative theories abound, translational
selection has been accepted as an important mechanism that shapes the patterns
of codon usage in prokaryotes and simple eukaryotes. Here we analyze patterns
of codon usage across 74 diverse bacteriophages that infect E. coli, P.
aeruginosa and L. lactis as their primary host. We introduce the concept of a
`genome landscape,' which helps reveal non-trivial, long-range patterns in
codon usage across a genome. We develop a series of randomization tests that
allow us to interrogate the significance of one aspect of codon usage, such a
GC content, while controlling for another aspect, such as adaptation to
host-preferred codons. We find that 33 phage genomes exhibit highly non-random
patterns in their GC3-content, use of host-preferred codons, or both. We show
that the head and tail proteins of these phages exhibit significant bias
towards host-preferred codons, relative to the non-structural phage proteins.
Our results support the hypothesis of translational selection on viral genes
for host-preferred codons, over a broad range of bacteriophages.
| [
{
"version": "v1",
"created": "Tue, 14 Aug 2007 22:44:18 GMT"
}
] | 2008-03-04T00:00:00 | [
[
"Lucks",
"Julius B.",
""
],
[
"Nelson",
"David R.",
""
],
[
"Kudla",
"Grzegorz",
""
],
[
"Plotkin",
"Joshua B.",
""
]
] |
0708.2039 | Lucy Hadfield | L. J. Hadfield and P. A. Crowther | A survey of the Wolf-Rayet population of the barred, spiral galaxy NGC
1313 | Accepted for publication in MNRAS. Finding charts omitted, full
version available by anonymous ftp (ftp:
hydra.shef.ac.uk/pub/lh/ngc1313-fullversion.pdf | null | 10.1111/j.1365-2966.2007.12284.x | null | astro-ph | null | We present a VLT/FORS1 survey of Wolf-Rayet (WR) stars in the spiral galaxy
NGC 1313. In total, 94 WR candidate sources have been identified from
narrow-band imaging. Of these, 82 have been spectroscopically observed, for
which WR emission features are confirmed in 70 cases, one of which also
exhibits strong nebular HeII 4686 emission. We also detect strong nebular HeII
4686 emission within two other regions of NGC 1313, one of which is a possible
supernova remnant. Nebular properties confirm that NGC 1313 has a metal-content
log(O/H)+12=8.23+/-0.06, in good agreement with previous studies. From
continuum subtracted Halpha images we infer a global star formation rate of 0.6
Msun/yr. Using template LMC WR stars, spectroscopy reveals that NGC 1313 hosts
a minimum of 84 WR stars. Our census comprises 51 WN stars, including a rare
WN/C transition star plus 32 WC stars. In addition, we identify one WO star
which represents the first such case identified beyond the Local Group. The
bright giant HII region PES 1, comparable in Halpha luminosity to NGC 595 in M
33, is found to host a minimum of 17 WR stars. The remaining photometric
candidates generally display photometric properties consistent with WN stars,
such that we expect a global WR population of ~115 stars with N(WR)/N(O)~0.01
and N(WC)/N(WN)~0.4.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:31:32 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 09:51:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hadfield",
"L. J.",
""
],
[
"Crowther",
"P. A.",
""
]
] |
0708.2040 | Alex Robinson | A. P. L. Robinson, M. Zepf, S. Kar, R. G. Evans and C. Bellei | Radiation Pressure Acceleration of Thin Foils with Circularly Polarized
Laser Pulses | null | null | 10.1088/1367-2630/10/1/013021 | null | physics.plasm-ph | null | A new regime is described for Radiation Pressure Acceleration of a thin foil
by an intense laser beam of above 10^20 W/cm^2. Highly monoenergetic proton
beams extending to GeV energies can be produced with very high efficiency using
circularly polarized light. The proton beams have a very small divergence angle
(less than 4 degrees). This new method allows the construction of ultra-compact
proton and ion accelerators with ultra-short particle bursts.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 10:21:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Robinson",
"A. P. L.",
""
],
[
"Zepf",
"M.",
""
],
[
"Kar",
"S.",
""
],
[
"Evans",
"R. G.",
""
],
[
"Bellei",
"C.",
""
]
] |
0708.2041 | Andrew Baker | Andrew Baker, Helen Gilmour and Philipp Reinhard | Topological Andr\'e-Quillen homology for cellular commutative
$S$-algebras | Final revision, a version will appear in Abhandlungen aus dem
Mathematischen Seminar der Universitaet Hamburg | null | 10.1007/s12188-008-0005-9 | null | math.AT math.KT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Topological Andr\'e-Quillen homology for commutative $S$-algebras was
introduced by Basterra following work of Kriz, and has been intensively studied
by several authors. In this paper we discuss it as a homology theory on CW
$S$-algebras and apply it to obtain results on minimal atomic $p$-local
$S$-algebras which generalise those of Baker and May for $p$-local spectra and
simply connected spaces. We exhibit some new examples of minimal atomic
$S$-algebras.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 14:03:50 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Aug 2007 10:13:28 GMT"
},
{
"version": "v3",
"created": "Thu, 4 Oct 2007 10:43:35 GMT"
},
{
"version": "v4",
"created": "Mon, 12 May 2008 16:05:05 GMT"
},
{
"version": "v5",
"created": "Fri, 8 Aug 2008 15:55:39 GMT"
}
] | 2008-08-08T00:00:00 | [
[
"Baker",
"Andrew",
""
],
[
"Gilmour",
"Helen",
""
],
[
"Reinhard",
"Philipp",
""
]
] |
0708.2042 | Christopher Evans | M. R. Mokiem, A. de Koter, J. S. Vink, J. Puls, C. J. Evans, S. J.
Smartt, P. A. Crowther, A. Herrero, N. Langer, D. J. Lennon, F. Najarro, M.
R. Villamariz | The empirical metallicity dependence of the mass-loss rate of O- and
early B-type stars | Accepted by A&A, 17 pages | Astron.Astrophys.473:603-614,2007 | 10.1051/0004-6361:20077545 | null | astro-ph | null | [Abridged] We present a comprehensive study of the metallicity dependence of
the mass-loss rates in stationary stellar winds of hot massive stars. Assuming
a power-law dependence of mass loss on metallicity, Mdot \propto Z^{m}, and
adopting a theoretical relation between the terminal velocity and metallicity,
v_inf \propto Z^{0.13} (Leitherer et al.), we find m = 0.83 +/- 0.16 for
non-clumped outflows from an analysis of the wind momentum luminosity relation
(WLR) for stars more luminous than 10^{5.2} Lsun. Within the errors, this
result agrees with the prediction of m = 0.69 +/- 0.10 from Vink et al. For the
high luminosity stars we find the mass loss rates to be greater than the
predictions, implying wind clumping factors in their line-forming regions of
~4. For lower luminosity stars, the winds are so weak that their strengths
cannot be reliably derived from optical lines, and one must rely on analysis of
UV lines. In the low-luminosity domain the Galactic WLR is found to be much
steeper than expected from theory, leading to a discrepancy between UV
mass-loss rates and the predictions by a factor 100 at luminosities of L ~
10^{4.75} Lsun, the origin of which is unknown. We emphasize that even if the
current mass-loss rates of hot luminous stars are overestimated as a result of
wind clumping, the degree of clumping would likely to be independent of
metallicity, so the scalings derived in this study are expected to remain
correct.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:01:13 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Mokiem",
"M. R.",
""
],
[
"de Koter",
"A.",
""
],
[
"Vink",
"J. S.",
""
],
[
"Puls",
"J.",
""
],
[
"Evans",
"C. J.",
""
],
[
"Smartt",
"S. J.",
""
],
[
"Crowther",
"P. A.",
""
],
[
"Herrero",
"A.",
""
],
[
"Langer",
"N.",
""
],
[
"Lennon",
"D. J.",
""
],
[
"Najarro",
"F.",
""
],
[
"Villamariz",
"M. R.",
""
]
] |
0708.2043 | Maciej Trzetrzelewski | Maciej Trzetrzelewski | The hamiltonian study of supersymmetric Yang-Mills quantum mechanics | 3 pages | Nucl. Phys. B171 (Proc. Suppl.) (2007) 325-327 | 10.1016/j.nuclphysbps.2007.06.046 | null | hep-th | null | The hamiltonian formulation of Supersymmetric Yang-Mills quantum mechanics
(SYMQM) is discussed. We focus on the Fock space formulation of the models
since it is convenient for the numerical analysis, however some novel
analytical results are also pointed out.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:16:50 GMT"
}
] | 2011-11-02T00:00:00 | [
[
"Trzetrzelewski",
"Maciej",
""
]
] |
0708.2044 | Luiz Renato Fontes | Roberto Fern\'andez, Luiz Renato Fontes, E. Jord\~ao Neves | Density-Profile Processes Describing Biological Signaling Networks:
Almost Sure Convergence to Deterministic Trajectories | 17 pages | null | null | null | math.PR | null | We introduce jump processes in R^k, called density-profile process, to model
biological signaling networks. They describe the macroscopic evolution of
finite-size spin-flip models with k types of spins interacting through a
non-reversible Glauber dynamics. We focus on the the k-dimensional
empirical-magnetization vector in the thermodynamic limit, and prove that,
within arbitrary finite time-intervals, its path converges almost surely to a
deterministic trajectory determined by a first-order (non-linear) differential
equation. As parameters of the spin-flip dynamics change, the associated
dynamical system may go through bifurcations, associated to phase transitions
in the statistical mechanical setting. We present a simple example of spin-flip
stochastic model leading to a dynamical system with Hopf and pitchfork
bifurcations; depending on the parameter values, the magnetization random path
can either converge to a unique stable fixed point, converge to one of a pair
of stable fixed points, or asymptotically evolve close to a deterministic orbit
in R^k.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:18:48 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Fernández",
"Roberto",
""
],
[
"Fontes",
"Luiz Renato",
""
],
[
"Neves",
"E. Jordão",
""
]
] |
0708.2045 | Jinn-Ouk Gong | Jinn-Ouk Gong | Sustainability of multi-field inflation and bound on string scale | (v1) 9 pages, 1 figure;(v2) 10 pages, references added; (v3) 15
pages, 4 figures, more discussions about parameters and observable
quantities, references added, to appear in Modern Physics Letters A | Mod.Phys.Lett.A24:2119-2132,2009 | 10.1142/S0217732309030552 | null | hep-th astro-ph hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of the interaction terms between the inflaton fields on
the inflationary dynamics in multi-field models. With power law type potential
and interactions, the total number of e-folds may get considerably reduced and
can lead to unacceptably short period of inflation. Also we point out that this
can place a bound on the characteristic scale of the underlying theory such as
string theory. Using a simple multi-field chaotic inflation model from string
theory, the string scale is constrained to be larger than the scale of grand
unified theory.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:23:35 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Aug 2007 01:59:17 GMT"
},
{
"version": "v3",
"created": "Wed, 11 Feb 2009 11:35:48 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Gong",
"Jinn-Ouk",
""
]
] |
0708.2046 | Gaetan Chenevier | Gaetan Chenevier | Quelques courbes de Hecke se plongent dans l'espace de Colmez | 19 pages, french. Minor revisions | null | null | null | math.NT | null | Let p be a prime, C the p-adic Eigencurve (with tame level 1) and Z the
blow-up of the Fredholm hypersurface of the U_p - operator at the special
points. We show that for p = 2, 3, 5 and 7, the natural map C -> Z is a
rigid-analytic isomorphism.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:30:49 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Oct 2007 17:23:10 GMT"
}
] | 2007-10-14T00:00:00 | [
[
"Chenevier",
"Gaetan",
""
]
] |
0708.2047 | Betti Hartmann | Y. Brihaye (Universite de Mons, Belgium) and B. Hartmann (LMPT Tours,
France) | Inflating branes inside topological defects and periodic structures | Proceedings of the 12th Conference on Recent Developments in Gravity
(NEB XII), Nafplio, Greece | J.Phys.Conf.Ser.68:012008,2007 | 10.1088/1742-6596/68/1/012008 | null | gr-qc | null | We study brane world models which contain local topological defects in the
bulk and a (3+1)-dimensional inflating brane. We put the emphasis on new types
of solutions that are periodic in the bulk radial coordinate and thus provide
examples of "naturally compactified" brane worlds.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:36:50 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Brihaye",
"Y.",
"",
"Universite de Mons, Belgium"
],
[
"Hartmann",
"B.",
"",
"LMPT Tours,\n France"
]
] |
0708.2048 | Siba Prasad Das | Siba Prasad Das, Amitava Datta, Monoranjan Guchait, Manas Maity and
Siddhartha Mukherjee | Focus Point SUSY at the LHC Revisited | 17 pages, 4 figures, minor typos correction | Eur.Phys.J.C54:645-653,2008 | 10.1140/epjc/s10052-008-0561-2 | BONN-TH-2007-05 | hep-ph hep-ex | null | The estimation of the backgrounds for gluino signals in focus point
supersymmetry is extended by including the backgrounds from the production of
four third generation quarks in the analysis. We find that these backgrounds
are negligible if one uses the strong selection criteria proposed in the
literature (including this analysis) for heavy gluino searches. Softer
selection criteria often recommended for lighter gluino searches yield
backgrounds which are small but numerically significant. We have also repeated
the more conventional background calculations and compared our results with the
other groups. We find that the size of the total residual background estimated
by different groups using different event generators and hard kinematical cuts
agree approximately. In view of the theoretical uncertainties in the leading
order signal and background cross sections mainly due to the choice of the QCD
scale, the gluino mass reach at the LHC cannot be pinpointed. However,
requiring a signal with $\rm\geq 3$ tagged b-jets (instead of the standard
choice of $\rm\geq 2$) it is shown that gluino masses close to 2 TeV can be
probed at the LHC for a range of reasonable choices of the QCD scale for an
integrated luminosity of 300 fb$^{-1}$.
| [
{
"version": "v1",
"created": "Wed, 15 Aug 2007 13:45:49 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 17:18:02 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Das",
"Siba Prasad",
""
],
[
"Datta",
"Amitava",
""
],
[
"Guchait",
"Monoranjan",
""
],
[
"Maity",
"Manas",
""
],
[
"Mukherjee",
"Siddhartha",
""
]
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.