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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0704.2801 | Alan L. T. Paterson | Alan L. T. Paterson | Continuous family groupoids | null | Homology, Homotopy and Applications 2 (2000), 89-104 | null | null | math.KT | null | In this paper, we define and investigate the properties of continuous family
groupoids. This class of groupoids is necessary for investigating the groupoid
index theory arising from the equivariant Atiyah-Singer index theorem for
families, and is also required in noncommutative geometry. The class includes
that of Lie groupoids, and the paper shows that, like Lie groupoids, continuous
family groupoids always admit (an essentially unique) continuous left Haar
system of smooth measures. We also show that the action of a continuous family
groupoid $G$ on a continuous family $G$-space fibered over another continuous
family $G$-space $Y$ can always be regarded as an action of the continuous
family groupoid $G*Y$ on an ordinary $G*Y$-space.
| [
{
"version": "v1",
"created": "Fri, 20 Apr 2007 22:14:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Paterson",
"Alan L. T.",
""
]
] |
0704.2802 | Alan L. T. Paterson | Alan L. T. Paterson and Amy E. Welch | Tychonoff's theorem for locally compact space and an elementary approach
to the topology of path spaces | null | Proceedings of the American Mathematical Society 133(2005),
2761-2770 | null | null | math.OA | null | The path spaces of a directed graph play an important role in the study of
graph $\css$. These are topological spaces that were originally constructed
using groupoid and inverse semigroup techniques. In this paper, we develop a
simple, purely topological, approach to this construction, based on Tychonoff's
theorem. In fact, the approach is shown to work even for higher dimensional
graphs satisfying the finitely aligned condition, and we construct the groupoid
of the graph. Motivated by these path space results, we prove a Tychonoff
theorem for an infinite, countable product of locally compact spaces. The main
idea is to include certain finite products of the spaces along with the
infinite product. We show that the topology is, in a reasonable sense, a
pointwise topology.
| [
{
"version": "v1",
"created": "Fri, 20 Apr 2007 22:19:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Paterson",
"Alan L. T.",
""
],
[
"Welch",
"Amy E.",
""
]
] |
0704.2803 | Jure Leskovec | Jure Leskovec, Mary McGlohon, Christos Faloutsos, Natalie Glance,
Matthew Hurst | Cascading Behavior in Large Blog Graphs | null | null | null | null | physics.soc-ph physics.data-an | null | How do blogs cite and influence each other? How do such links evolve? Does
the popularity of old blog posts drop exponentially with time? These are some
of the questions that we address in this work. Our goal is to build a model
that generates realistic cascades, so that it can help us with link prediction
and outlier detection.
Blogs (weblogs) have become an important medium of information because of
their timely publication, ease of use, and wide availability. In fact, they
often make headlines, by discussing and discovering evidence about political
events and facts. Often blogs link to one another, creating a publicly
available record of how information and influence spreads through an underlying
social network. Aggregating links from several blog posts creates a directed
graph which we analyze to discover the patterns of information propagation in
blogspace, and thereby understand the underlying social network. Not only are
blogs interesting on their own merit, but our analysis also sheds light on how
rumors, viruses, and ideas propagate over social and computer networks.
Here we report some surprising findings of the blog linking and information
propagation structure, after we analyzed one of the largest available datasets,
with 45,000 blogs and ~ 2.2 million blog-postings. Our analysis also sheds
light on how rumors, viruses, and ideas propagate over social and computer
networks. We also present a simple model that mimics the spread of information
on the blogosphere, and produces information cascades very similar to those
found in real life.
| [
{
"version": "v1",
"created": "Fri, 20 Apr 2007 22:37:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Leskovec",
"Jure",
""
],
[
"McGlohon",
"Mary",
""
],
[
"Faloutsos",
"Christos",
""
],
[
"Glance",
"Natalie",
""
],
[
"Hurst",
"Matthew",
""
]
] |
0704.2804 | Yi Lin | Yi Lin | The Equivariant cohomology theory of twisted generalized complex
manifolds | 32 pages. This is the revised version which is going to appear in
Commu. in Math. Physics. A few minor errors in version 2 are corrected | Commun.Math.Phys.281:469-497,2008 | 10.1007/s00220-008-0482-9 | null | math.DG hep-th math.SG | null | It has been shown recently by Kapustin and Tomasiello that the mathematical
notion of Hamiltonian actions on twisted generalized K\"ahler manifolds is in
perfect agreement with the physical notion of general $(2,2)$ gauged sigma
models with three-form fluxes. In this article, we study the twisted
equivariant cohomology theory of Hamiltonian actions on $H$-twisted generalized
complex manifolds. If the manifold satisfies the
$\bar{\partial}\partial$-lemma, we establish the equivariant formality theorem.
If in addition, the manifold satisfies the generalized K\"ahler condition, we
prove the Kirwan injectivity in this setting. We then consider the Hamiltonian
action of a torus on an $H$-twisted generalized Calabi-Yau manifold and extend
to this case the Duistermaat-Heckman theorem for the push-forward measure.
As a side result, we show in this paper that the generalized K\"ahler
quotient of a generalized K\"ahler vector space can never have a
(cohomologically) non-trivial twisting. This gives a negative answer to a
question asked by physicists whether one can construct $(2,2)$ gauged linear
sigma models with non-trivial fluxes.
| [
{
"version": "v1",
"created": "Fri, 20 Apr 2007 23:18:14 GMT"
},
{
"version": "v2",
"created": "Sat, 3 Nov 2007 00:32:58 GMT"
},
{
"version": "v3",
"created": "Tue, 13 Nov 2007 16:04:44 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lin",
"Yi",
""
]
] |
0704.2805 | Tsz Ho Chan | Tsz Ho Chan | Approximating reals by sums of rationals | 8 pages | null | null | null | math.NT | null | We consider the question of approximating any real number $\alpha$ by sums of
$n$ rational numbers $\frac{a_1}{q_1} + \frac{a_2}{q_2} + ... +
\frac{a_n}{q_n}$ with denominators $1 \leq q_1, q_2, ..., q_n \leq N$. This
leads to an inquiry on approximating a real number by rational numbers with a
prescribed number of prime factors in the denominator.
| [
{
"version": "v1",
"created": "Fri, 20 Apr 2007 23:18:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chan",
"Tsz Ho",
""
]
] |
0704.2806 | Yoshimasa Hidaka | Kenji Fukushima and Yoshimasa Hidaka | Light projectile scattering off the Color Glass Condensate | 18 pages, 4 figures, references added, typos corrected | JHEP 0706:040,2007 | 10.1088/1126-6708/2007/06/040 | RBRC-667 | hep-ph | null | We systematically compute the Gaussian average of Wilson lines inherent in
the Color Glass Condensate, which provides useful formulae for evaluation of
the scattering amplitude in the collision of a light projectile and a heavy
target.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 00:03:08 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Jun 2007 14:35:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fukushima",
"Kenji",
""
],
[
"Hidaka",
"Yoshimasa",
""
]
] |
0704.2807 | Tatsuo Kobayashi | Pyungwon Ko, Tatsuo Kobayashi, Jae-hyeon Park, Stuart Raby | String-derived D4 flavor symmetry and phenomenological implications | 17 pages, no figure | Phys.Rev.D76:035005,2007; Erratum-ibid.D76:059901,2007 | 10.1103/PhysRevD.76.035005 10.1103/PhysRevD.76.059901 | null | hep-ph hep-th | null | In this paper we show how some flavor symmetries may be derived from the
heterotic string, when compactified on a 6D orbifold. In the body of the paper
we focus on the $D_4$ family symmetry, recently obtained in $Z_3 \times Z_2$
orbifold constructions. We show how this flavor symmetry constrains fermion
masses, as well as the soft SUSY breaking mass terms. Flavor symmetry breaking
can generate the hierarchy of fermion masses and at the same time the flavor
symmetry suppresses large flavor changing neutral current processes.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 00:30:12 GMT"
}
] | 2014-02-18T00:00:00 | [
[
"Ko",
"Pyungwon",
""
],
[
"Kobayashi",
"Tatsuo",
""
],
[
"Park",
"Jae-hyeon",
""
],
[
"Raby",
"Stuart",
""
]
] |
0704.2808 | Aditya Ramamoorthy | Aditya Ramamoorthy | Minimum cost distributed source coding over a network | First version apppeared in the Proceedings of the 2007 IEEE
International Symposium on Information Theory, Nice, France, June 24 - 29,
2007. The second version is an expanded journal submission under
consideration at the IEEE Transactions on Information Theory | null | null | null | cs.IT cs.NI math.IT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This work considers the problem of transmitting multiple compressible sources
over a network at minimum cost. The aim is to find the optimal rates at which
the sources should be compressed and the network flows using which they should
be transmitted so that the cost of the transmission is minimal. We consider
networks with capacity constraints and linear cost functions. The problem is
complicated by the fact that the description of the feasible rate region of
distributed source coding problems typically has a number of constraints that
is exponential in the number of sources. This renders general purpose solvers
inefficient. We present a framework in which these problems can be solved
efficiently by exploiting the structure of the feasible rate regions coupled
with dual decomposition and optimization techniques such as the subgradient
method and the proximal bundle method.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 17:41:35 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Aug 2009 22:56:01 GMT"
}
] | 2009-08-13T00:00:00 | [
[
"Ramamoorthy",
"Aditya",
""
]
] |
0704.2809 | Qing-Hong Cao | Qing-Hong Cao, Jose Wudka, C.-P. Yuan | Search for New Physics via Single Top Production at the LHC | version to appear in Physics Letters B | Phys.Lett.B658:50-56,2007 | 10.1016/j.physletb.2007.10.057 | UCRHEP-T427 | hep-ph | null | We consider single-top production as a probe for new physics effects at the
Large Hadron Collider (LHC). We argue that for natural theories a small
deviation from the Standard Model tree-level couplings in this reaction can be
parameterized by 3 higher dimension operators. Precision measurement of these
effective couplings in the single-top events, via studying their interference
effects with the SM contributions, can discriminate several new physics models.
In particular, combining the production rate of three single-top production
modes will provide a severe test of the Little Higgs model with T-parity. We
find that at the LHC, a 5% accuracy in the measurement of the single-top cross
sections would probe the new physics scale up to about $3 {\rm TeV}$.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 02:25:11 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Nov 2007 00:52:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cao",
"Qing-Hong",
""
],
[
"Wudka",
"Jose",
""
],
[
"Yuan",
"C. -P.",
""
]
] |
0704.2810 | Kotaro Yamada | Kentaro Saji, Masaaki Umehara and Kotaro Yamada | Behavior of corank one singular points on wave fronts | 20 pages, 12 figures | null | null | null | math.DG | null | Let $M^2$ be an oriented 2-manifold and $f:M^2\to R^3$ a $C^\infty$-map. A
point $p\in M^2$ is called a singular point if $f$ is not an immersion at $p$.
The map $f$ is called a front (or wave front), if there exists a unit
$C^\infty$-vector field $\nu$ such that the image of each tangent vector
$df(X)$ $(X\in TM^2)$ is perpendicular to $\nu$, and the pair $(f,\nu)$ gives
an immersion into $R^3\times S^2$. In our previous paper, we gave an intrinsic
formulation of wave fronts in $R^3$. In this paper, we shall investigate the
behavior of cuspidal edges near corank one singular points and establish
Gauss-Bonnet-type formulas under the intrinsic formulation.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 02:22:45 GMT"
},
{
"version": "v2",
"created": "Fri, 18 May 2007 00:47:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Saji",
"Kentaro",
""
],
[
"Umehara",
"Masaaki",
""
],
[
"Yamada",
"Kotaro",
""
]
] |
0704.2811 | Nandakishore Santhi | Nandakishore Santhi | On Algebraic Decoding of $q$-ary Reed-Muller and Product-Reed-Solomon
Codes | 5 pages, 5 figures, to be presented at 2007 IEEE International
Symposium on Information Theory, Nice, France (ISIT 2007) | null | 10.1109/ISIT.2007.4557130 | LA-UR-07-0469 | cs.IT cs.DM math.IT | null | We consider a list decoding algorithm recently proposed by Pellikaan-Wu
\cite{PW2005} for $q$-ary Reed-Muller codes $\mathcal{RM}_q(\ell, m, n)$ of
length $n \leq q^m$ when $\ell \leq q$. A simple and easily accessible
correctness proof is given which shows that this algorithm achieves a relative
error-correction radius of $\tau \leq (1 - \sqrt{{\ell q^{m-1}}/{n}})$. This is
an improvement over the proof using one-point Algebraic-Geometric codes given
in \cite{PW2005}. The described algorithm can be adapted to decode
Product-Reed-Solomon codes.
We then propose a new low complexity recursive algebraic decoding algorithm
for Reed-Muller and Product-Reed-Solomon codes. Our algorithm achieves a
relative error correction radius of $\tau \leq \prod_{i=1}^m (1 -
\sqrt{k_i/q})$. This technique is then proved to outperform the Pellikaan-Wu
method in both complexity and error correction radius over a wide range of code
rates.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 00:22:46 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Santhi",
"Nandakishore",
""
]
] |
0704.2812 | Yu-Xiao Liu | Yu-Xiao Liu, Li Zhao, Xin-Hui Zhang, Yi-Shi Duan | Fermions in Self-dual Vortex Background on a String-like Defect | 16 pages, no figures; V2: 16 pages with some changes, accepted by
Nucl. Phys. B | Nucl.Phys.B785:234-245,2007 | 10.1016/j.nuclphysb.2007.05.018 | null | hep-th | null | By using the self-dual vortex background on extra two-dimensional Riemann
surfaces in 5+1 dimensions, the localization mechanism of bulk fermions on a
string-like defect with the exponentially decreasing warp-factor is obtained.
We give the conditions under which localized spin 1/2 and 3/2 fermions can be
obtained.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 03:28:46 GMT"
},
{
"version": "v2",
"created": "Mon, 14 May 2007 09:02:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Liu",
"Yu-Xiao",
""
],
[
"Zhao",
"Li",
""
],
[
"Zhang",
"Xin-Hui",
""
],
[
"Duan",
"Yi-Shi",
""
]
] |
0704.2813 | Toufik Mansour Dr. | Toufik Mansour, Matthias Schork, Yidong Sun | Motzkin numbers of higher rank: Generating function and explicit
expression | null | J. Integer Seq. 10 (2007), Article 07.7.4 | null | null | math.CO | null | The generating function and an explicit expression is derived for the
(colored) Motzkin numbers of higher rank introduced recently. Considering the
special case of rank one yields the corresponding results for the conventional
colored Motzkin numbers for which in addition a recursion relation is given.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 04:37:53 GMT"
},
{
"version": "v2",
"created": "Sun, 13 May 2007 14:53:19 GMT"
}
] | 2007-10-06T00:00:00 | [
[
"Mansour",
"Toufik",
""
],
[
"Schork",
"Matthias",
""
],
[
"Sun",
"Yidong",
""
]
] |
0704.2814 | Qiang Liu | Qiang Liu and Shou-Li Peng | A Revised Generalized Kolmogorov-Sinai-like Entropy and Markov Shifts | 11 pages | null | null | null | nlin.CD | null | The Kolmogorov-Sinai entropy in the sense of Tsallis under Bernoulli shifts
was obtained by Meson and Vericat [J. Math. Phys. 37, 4480(1996)]. In this
paper, we propose a revised generalized Kolmogorov-Sinai-q entropy under Markov
shifts. The form of this generalized entropy with factor q is nonextensive. The
new generalized entropy contains the classical Kolmogorov-Sinai entropy and
Renyi entropy as well as Bernoulli shifts as special cases. Applying the
generalized entropy we discuss its approximate behavior qualitatively, the
entropy rate and the sensitive value q^* of the nonextensive parameter q, which
may exit in the interval (-2,2) nearby where the generalized entropy return to
the classical K-S entropy.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 04:52:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Liu",
"Qiang",
""
],
[
"Peng",
"Shou-Li",
""
]
] |
0704.2815 | Asterios Pantokratoras | Asterios Pantokratoras | Comments on six papers published by S.P. Anjali Devi and R. Kandasamy | Comments on six papers published by S.P. Anjali Devi and R. Kandasamy
in Heat and Mass Transfer, ZAMM, Mechanics Research Communications,
International Communications in Heat and Mass Transfer, Communications in
Numerical Methods in Engineering, Journal of Computational and Applied
Mechanics | null | null | null | physics.flu-dyn | null | Comments on six papers published by S.P. Anjali Devi and R. Kandasamy in Heat
and Mass Transfer, ZAMM, Mechanics Research Communications, International
Communications in Heat and Mass Transfer, Communications in Numerical Methods
in Engineering, Journal of Computational and Applied Mechanics
In conclusion all the above papers are of very low quality, written without
care and are partly or completely wrong.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 05:52:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pantokratoras",
"Asterios",
""
]
] |
0704.2816 | Jay G. Wacker | Mariangela Lisanti, Jay G. Wacker | Unification and Dark Matter in a Minimal Scalar Extension of the
Standard Model | 10 pages, 7 figures; added references; corrected typos | null | null | SLAC-PUB-12480 | hep-ph | null | The six Higgs doublet model is a minimal extension of the Standard Model that
addresses dark matter and gauge coupling unification. Another Higgs doublet in
a 5 representation of a discrete symmetry group, such as S_6, is added to the
SM. The lightest components of the 5-Higgs are neutral, stable and serve as
dark matter so long as the discrete symmetry is not broken. Direct and indirect
detection signals, as well as collider signatures are discussed. The five-fold
multiplicity of the dark matter decreases its mass and typically helps make the
dark matter more visible in upcoming experiments.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 06:57:21 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 00:56:04 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Lisanti",
"Mariangela",
""
],
[
"Wacker",
"Jay G.",
""
]
] |
0704.2817 | Masaki Kashiwara | Naoya Enomoto and Masaki Kashiwara | Symmetric Crystals for $\gl_\infty$ | 39pages | Publ. Res. Inst. Math. Sci. 44 (2008), no. 3, 837--891 | null | null | math.QA math.RT | null | In the preceding paper, we formulated a conjecture on the relations between
certain classes of irreducible representations of affine Hecke algebras of type
B and symmetric crystals for $\gl_\infty$. In the present paper, we prove the
existence of the symmetric crystal and the global basis for $\gl_\infty$.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 08:15:47 GMT"
}
] | 2015-12-22T00:00:00 | [
[
"Enomoto",
"Naoya",
""
],
[
"Kashiwara",
"Masaki",
""
]
] |
0704.2818 | Kotaro Kohno | Kotaro Kohno (1), Koichiro Nakanishi (2), Masatoshi Imanishi (2) ((1)
Institute of Astronomy, Univ. of Tokyo, (2) National Astronomical Observatory
of Japan) | Compact starburst in the central regions of Seyfert galaxies | Conference proceedings to appear in "The Central Engine of Active
Galactic Nuclei", ed. L. C. Ho and J.-M. Wang (San Francisco: ASP) | null | null | null | astro-ph | null | We have conducted a high-resolution ``3D'' imaging survey of the CO(1--0),
HCN(1--0), and HCO$^+$(1--0) lines toward the central a few kpc regions of the
Seyfert and starburst galaxies in the local universe using the Nobeyama
Millimeter Array. We detected luminous HCN(1--0) emissions toward a
considerable fraction of these Seyfert galaxies (10 of 12 in our sub-sample),
which indicated that some of these Seyfert galaxies, such as NGC 3079, NGC
3227, NGC 4051, NGC 6764, and NGC 7479, are indeed accompanied with compact
nuclear starburst, given the tight correlation between the HCN(1--0) luminosity
and the star formation rate among star-forming galaxies. However, we suggest
that the elevated HCN(1--0) emission from some of these Seyfert galaxies,
including NGC 1068, NGC 1097, NGC 5033, and NGC 5194, does not signify the
presence of massive starbursts there. This is because these Seyfert nuclei show
abnormally high HCN(1--0)/HCO$^+$(1--0) ratios (2--3), which were never
observed in the starburst nuclei in our sample. This could be attributed to the
overabundance of HCN molecules in the X-ray dominated regions (XDRs) at the
centers of these Seyfert galaxies.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 08:20:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kohno",
"Kotaro",
""
],
[
"Nakanishi",
"Koichiro",
""
],
[
"Imanishi",
"Masatoshi",
""
]
] |
0704.2819 | Alexander G. Ramm | A.G.Ramm | Wave scattering by small impedance particles in a medium | null | null | 10.1016/j.physleta.2007.04.061 | null | math-ph math.MP | null | The theory of acoustic wave scattering by many small bodies is developed for
bodies with impedance boundary condition. It is shown that if one embeds many
small particles in a bounded domain, filled with a known material, then one can
create a new material with the properties very different from the properties of
the original material. Moreover, these very different properties occur although
the total volume of the embedded small particles is negligible compared with
the volume of the original material.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 15:07:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ramm",
"A. G.",
""
]
] |
0704.2820 | Sungeun Kim | S. Kim and C. Park | Topology of HI in the Large Magellanic Cloud | 6 pages, 5 figures, accepted for publication in ApJ | Astrophys.J.663:244-248,2007 | 10.1086/518470 | null | astro-ph | null | We have analyzed the HI aperture synthesis image of the Large Magellanic
Cloud (LMC), using an objective and quantitative measure of topology to
understand the HI distribution hosting a number of holes and clumps of various
sizes in the medium. The HI distribution shows different topology at four
different chosen scales. At the smallest scales explored (19-29 pc), the HI
mass is distributed in such a way that numerous clumps are embedded on top of a
low density background. At the larger scales from 73 to 194 pc, it shows a
generic hole topology. These holes might have been formed mainly by stellar
winds from hot stars. At the scales from 240 to 340 pc, slightly above the disk
scale-height of the gaseous disk, major clumps in the HI map change the
distribution to have a slight clump topology. These clumps include the giant
cloud associations in the spiral arms and the thick filaments surrounding
superholes. At the largest scales studied (390-485 pc), the hole topology is
present again. Responsible to the hole topology at this scale are a few
superholes which seem mainly associated with supernova explosions in the outer
disk. The gaps between the bar and spiral arms have a minor effect on the
topology at this scale.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 01:54:02 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Apr 2007 21:37:18 GMT"
},
{
"version": "v3",
"created": "Tue, 1 May 2007 04:46:36 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kim",
"S.",
""
],
[
"Park",
"C.",
""
]
] |
0704.2821 | Sungeun Kim | H-S. Kim, S. Kim, J.Y. Bak, M. Garcia, B. Brandl, K. Xiao, W. Walsh,
R.C. Smith, S. Youn | IRAC Observations of CO J=4-3 High-Velocity Cloud in the 30 Doradus
Complex in the Large Magellanic Cloud | 17 pages, 7 figures, Submitted to ApJ | null | 10.1086/521589 | null | astro-ph | null | We compare the CO 2-1 observations against previously taken CO 4-3
observations and analyze the spatial distribution of young stellar objects
(YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus
complex. Both peaks of CO 2-1 and 4-3 emitting clouds coincide with the densest
region of the filaments where multiple shells are colliding. We find that the
YSO's are clustered in the southern ridge of the warm and dense molecular gas
clouds traced by CO J=4-3, indicating a filamentary structure of star formation
throughout the 30 Doradus. We also find that some of Class I YSO's candidates
which are likely to be associated with a high-velocity component of CO 4-3
emitting clouds are present. This is a bona fide place where the triggered star
formation had happened and newly formed stars may have produced such a
high-velocity outflow interacting with the surrounding molecular cloud
material.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 02:25:37 GMT"
},
{
"version": "v2",
"created": "Tue, 1 May 2007 05:12:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kim",
"H-S.",
""
],
[
"Kim",
"S.",
""
],
[
"Bak",
"J. Y.",
""
],
[
"Garcia",
"M.",
""
],
[
"Brandl",
"B.",
""
],
[
"Xiao",
"K.",
""
],
[
"Walsh",
"W.",
""
],
[
"Smith",
"R. C.",
""
],
[
"Youn",
"S.",
""
]
] |
0704.2822 | Yury Kozhedub Sergeevich | Y. S. Kozhedub, D. A. Glazov, A. N. Artemyev, N. S. Oreshkina, V. M.
Shabaev, I. I. Tupitsyn, A. V. Volotka, and G. Plunien | QED calculation of the 2p1/2-2s and 2p3/2-2s transition energies and the
ground-state hyperfine splitting in lithiumlike scandium | 10 pages, 2 tables | Phys. Rev. A 76, 012511 (2007) | 10.1103/PhysRevA.76.012511 | null | physics.atom-ph | null | We present the most accurate up-to-date theoretical values of the
{2p_{1/2}}-{2s} and {2p_{3/2}}-{2s} transition energies and the ground-state
hyperfine splitting in ${\rm Sc}^{18+}$. All two- and three-electron
contributions to the energy values up to the two-photon level are treated in
the framework of bound-state QED without $\aZ$-expansion. The interelectronic
interaction beyond the two-photon level is taken into account by means of the
large-scale configuration-interaction Dirac-Fock-Sturm (CI-DFS) method. The
relativistic recoil correction is calculated with many-electron wave functions
in order to take into account the electron-correlation effect. The accuracy of
the transition energy values is improved by a factor of five compared to the
previous calculations. The CI-DFS calculation of interelectronic-interaction
effects and the evaluation of the QED correction in an effective screening
potential provide significant improvement for the $2s$ hyperfine splitting. The
results obtained are in a good agreement with recently published experimental
data.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 09:44:49 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 17:38:42 GMT"
}
] | 2007-08-06T00:00:00 | [
[
"Kozhedub",
"Y. S.",
""
],
[
"Glazov",
"D. A.",
""
],
[
"Artemyev",
"A. N.",
""
],
[
"Oreshkina",
"N. S.",
""
],
[
"Shabaev",
"V. M.",
""
],
[
"Tupitsyn",
"I. I.",
""
],
[
"Volotka",
"A. V.",
""
],
[
"Plunien",
"G.",
""
]
] |
0704.2823 | Akira Ohnishi | A. Ohnishi, N. Kawamoto, K. Miura, K. Tsubakihara, H. Maekawa
(Hokkaido U.) | Strong coupling limit/region of lattice QCD | Presented at Yukawa International Seminar (YKIS) 2006 on New
Frontiers in QCD: Exotic Hadrons and Hadronic Matter, Kyoto, Japan, 20 Nov -
8 Dec 2006 | Prog.Theor.Phys.Suppl.168:261-264,2007 | 10.1143/PTPS.168.261 | null | nucl-th | null | We study the phase diagram of quark matter and nuclear properties based on
the strong coupling expansion of lattice QCD. Both of baryon and finite
coupling correction are found to have effects to extend the hadron phase to a
larger mu direction relative to Tc. In a chiral RMF model with logarithmic
sigma potential derived in the strong coupling limit of lattice QCD, we can
avoid the chiral collapse and normal and hypernuclei properties are well
described.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 10:23:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ohnishi",
"A.",
"",
"Hokkaido U."
],
[
"Kawamoto",
"N.",
"",
"Hokkaido U."
],
[
"Miura",
"K.",
"",
"Hokkaido U."
],
[
"Tsubakihara",
"K.",
"",
"Hokkaido U."
],
[
"Maekawa",
"H.",
"",
"Hokkaido U."
]
] |
0704.2824 | Christopher J. Hillar | Christopher J. Hillar | Sums of squares over totally real fields are rational sums of squares | 10 pages, final version to appear in Proceedings of the AMS | null | null | null | math.AC math.OC math.RA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let $K$ be a totally real number field with Galois closure $L$. We prove that
if $f \in \mathbb Q[x_1,...,x_n]$ is a sum of $m$ squares in $K[x_1,...,x_n]$,
then $f$ is a sum of \[4m \cdot 2^{[L: \mathbb Q]+1} {[L: \mathbb Q] +1 \choose
2}\] squares in $\mathbb Q[x_1,...,x_n]$. Moreover, our argument is
constructive and generalizes to the case of commutative $K$-algebras. This
result gives a partial resolution to a question of Sturmfels on the algebraic
degree of certain semidefinite programing problems.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 11:35:51 GMT"
},
{
"version": "v2",
"created": "Sat, 9 Jun 2007 21:16:35 GMT"
},
{
"version": "v3",
"created": "Tue, 1 Apr 2008 02:46:59 GMT"
},
{
"version": "v4",
"created": "Fri, 29 Aug 2008 19:01:05 GMT"
}
] | 2008-08-29T00:00:00 | [
[
"Hillar",
"Christopher J.",
""
]
] |
0704.2825 | Takatoshi Ichikawa | Takatoshi Ichikawa, Kouichi Hagino and Akira Iwamoto | Existence of One-Body Barrier Revealed in Deep Sub-Barrier Fusion | 4 pages, 3 figures | Phys.Rev.C75:057603,2007 | 10.1103/PhysRevC.75.057603 | null | nucl-th | null | Based on the adiabatic picture for heavy-ion reactions, in which the neck
formation in the one-body system is taken into account, we propose a two-step
model for fusion cross sections at deep subbarrier energies. This model
consists of the capture process in the two-body potential pocket, which is
followed by the penetration of the adiabatic one-body potential to reach a
compound state after the touching configuration. We describe the former process
with the coupled-channels framework, while the latter with the WKB
approximation by taking into account the coordinate dependent inertia mass. The
effect of the one-body barrier is important at incident energies below the
potential energy at the touching configuration. We show that this model well
accounts for the steep fall-off phenomenon of fusion cross sections at deep
subbarrier energies for the $^{64}$Ni+$^{64}$Ni and $^{58}$Ni+$^{58}$Ni
reactions.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 11:23:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ichikawa",
"Takatoshi",
""
],
[
"Hagino",
"Kouichi",
""
],
[
"Iwamoto",
"Akira",
""
]
] |
0704.2826 | Nabil Kahale | Nabil Kahale | Analytic crossing probabilities for certain barriers by Brownian motion | Published in at http://dx.doi.org/10.1214/07-AAP488 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org) | Annals of Applied Probability 2008, Vol. 18, No. 4, 1424-1440 | 10.1214/07-AAP488 | IMS-AAP-AAP488 | math.PR math.FA math.ST stat.TH | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate crossing probabilities and one-sided last exit time densities
for a class of moving barriers on an interval $[0,T]$ via Schwartz
distributions. We derive crossing probabilities and first hitting time
densities for another class of barriers on $[0,T]$ by proving a Schwartz
distribution version of the method of images. Analytic expressions for crossing
probabilities and related densities are given for new explicit and
semi-explicit barriers.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 21:13:44 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Aug 2008 12:55:33 GMT"
}
] | 2008-08-28T00:00:00 | [
[
"Kahale",
"Nabil",
""
]
] |
0704.2827 | Takatoshi Ichikawa | Takatoshi Ichikawa, Kouichi Hagino and Akira Iwamoto | Systematics of threshold incident energy for deep sub-barrier fusion
hindrance | 5 pages, 3 figures | Phys.Rev.C75:064612,2007 | 10.1103/PhysRevC.75.064612 | null | nucl-th | null | We systematically evaluate the potential energy at the touching configuration
for heavy-ion reactions using various potential models. We point out that the
energy at the touching point, especially that estimated with the
Krappe-Nix-Sierk (KNS) potential, strongly correlates with the threshold
incident energy for steep fall-off of fusion cross sections observed recently
for several systems at extremely low energies. This clearly indicates that the
steep fall-off phenomenon can be attributed to the dynamics after the target
and projectile touch with each other, e.g., the tunneling process and the
nuclear saturation property in the overlap region.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 12:14:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ichikawa",
"Takatoshi",
""
],
[
"Hagino",
"Kouichi",
""
],
[
"Iwamoto",
"Akira",
""
]
] |
0704.2828 | Meredith Wills-Davey | M. J. Wills-Davey, C. E. DeForest, and J. O. Stenflo | Are "EIT Waves" Fast-Mode MHD Waves? | to be published in the Astrophysical Journal | Astrophys.J.664:556-562,2007 | 10.1086/519013 | null | astro-ph | null | We examine the nature of large-scale, coronal, propagating wave fronts (``EIT
waves'') and find they are incongruous with solutions using fast-mode MHD
plane-wave theory. Specifically, we consider the following properties:
non-dispersive single pulse manifestions, observed velocities below the local
Alfven speed, and different pulses which travel at any number of constant
velocities, rather than at the ``predicted'' fast-mode speed. We discuss the
possibility of a soliton-like explanation for these phenomena, and show how it
is consistent with the above-mentioned aspects.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 17:30:18 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Wills-Davey",
"M. J.",
""
],
[
"DeForest",
"C. E.",
""
],
[
"Stenflo",
"J. O.",
""
]
] |
0704.2829 | Anna Morozovska Nickolaevna | Anna N. Morozovska, Sergei V. Svechnikov, Eugene A. Eliseev, and
Sergei V. Kalinin | Extrinsic Size Effect in Piezoresponse Force Microscopy of Thin Films | 16 pages, 5 figures; To be submitted to Phys. Rev. B-Rapid
Communications | null | 10.1103/PhysRevB.76.054123 | null | cond-mat.mtrl-sci | null | The extrinsic size effect in Piezoresponse Force Microscopy of ferroelectric
and piezoelectric thin films on non-polar dielectric substrate is analyzed.
Analytical expressions for effective piezoresponse, object transfer function
components, and Rayleigh two-point resolution are obtained. These results can
be broadly applied for effective piezoelectric response calculations in thin
piezoelectric and ferroelectric films as well as surface polar layers e.g. in
organic materials and bio-polymers. In particular, the effective piezoresponse
strongly decreases with film thickness whereas the sharpness of domain stripes
image increases due to the object transfer function spectrum broadening.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 12:49:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Morozovska",
"Anna N.",
""
],
[
"Svechnikov",
"Sergei V.",
""
],
[
"Eliseev",
"Eugene A.",
""
],
[
"Kalinin",
"Sergei V.",
""
]
] |
0704.2830 | Shin-ichi Kimura | Shin-ichi Kimura, Noriaki Kimura and Haruyoshi Aoki | Low-Energy Electrodynamics of Heavy Quasiparticles in ZrZn2 | 5 pages, 5 figures | null | 10.1143/JPSJ.76.084710 | null | cond-mat.str-el cond-mat.mtrl-sci | null | The temperature dependence of the optical conductivity spectrum of an
itinerant ferromagnetic material, ZrZn$_2$, was obtained and the dynamical
effective mass and the scattering rate were derived. A renormalized Drude peak
with a heavy effective mass developed at low temperatures. The effective mass
rapidly increased below $\hbar\omega$ = 10 meV and at 10 K it was observed to
be 3 times heavier than that at 300 K. The scattering rate also rapidly
decreased below 10 meV at 10 K. These results indicate the creation of heavy
quasiparticles at low temperatures due to spin fluctuations.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 13:00:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kimura",
"Shin-ichi",
""
],
[
"Kimura",
"Noriaki",
""
],
[
"Aoki",
"Haruyoshi",
""
]
] |
0704.2831 | Luis O. Silva | J. E. Santos, L. O. Silva, R. Bingham | White-light parametric instabilities in plasmas | 6 pages, 3 figures, accepted for publication in Phys. Rev. Lett | null | 10.1103/PhysRevLett.98.235001 | null | physics.plasm-ph | null | Parametric instabilities driven by partially coherent radiation in plasmas
are described by a generalized statistical Wigner-Moyal set of equations,
formally equivalent to the full wave equation, coupled to the plasma fluid
equations. A generalized dispersion relation for Stimulated Raman Scattering
driven by a partially coherent pump field is derived, revealing a growth rate
dependence, with the coherence width $\sigma$ of the radiation field, scaling
with $1/\sigma$ for backscattering (three-wave process), and with
$1/\sigma^{1/2}$ for direct forward scattering (four-wave process). Our results
demonstrate the possibility to control the growth rates of these instabilities
by properly using broadband pump radiation fields.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 13:22:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Santos",
"J. E.",
""
],
[
"Silva",
"L. O.",
""
],
[
"Bingham",
"R.",
""
]
] |
0704.2832 | Wei-Xing Zhou | Miao-Ren Niu, Qin-Feng Liang, Wei-Xing Zhou, Fu-Chen Wang, Zun-Hong Yu
(ECUST) | Endogenous and exogenous dynamics of pressure fluctuations in an
impinging entrained-flow gasifier | This paper has been withdrawn | null | null | null | physics.flu-dyn | null | This paper has been withdrawn by the authors due to a fatal error in the
analysis. The manuscript was submitted to Chemical Engineering Science. To
clarify the situation, we copy the main comment from an anonymous referee here:
"To my understanding, the authors analyze i = 1 ... 63 time series and
calculate their mean and standard deviation. These time series correspond to
individual, single ignition processes. Is this correct? If yes, these
processes, as Fig. 3 shows very clearly, are not stationary, and the pressure
difference (i.e., the signal) quickly decays to zero. In this case both the
mean and the standard deviation are poorly defined, for example because both
depend in a trivial fashion on the observation period T. I am not aware of any
study (including those cited by the authors) which allows for any conclusion
from such non-stationary signals. The results of Menezes and Barabasi are
strictly only valid for stationary time series, and they cannot be applied at
all in this case." We agree with this insightful comment that our data are not
stationary and the method adopted in our manuscript does not apply. We do not
see any possibility to correct this error and decide to withdraw it. We would
like to thank gratefully the referee and apologize for any inconvenience caused
by our oversight.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 14:09:31 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 13:54:04 GMT"
}
] | 2007-11-11T00:00:00 | [
[
"Niu",
"Miao-Ren",
"",
"ECUST"
],
[
"Liang",
"Qin-Feng",
"",
"ECUST"
],
[
"Zhou",
"Wei-Xing",
"",
"ECUST"
],
[
"Wang",
"Fu-Chen",
"",
"ECUST"
],
[
"Yu",
"Zun-Hong",
"",
"ECUST"
]
] |
0704.2833 | Sagun Chanillo | Sagun Chanillo and Juan J. Manfredi | Sharp Global Bounds for the Hessian on Pseudo-Hermitian Manifolds | 13 pages | null | null | null | math.AP math.DG | null | We find sharp bounds for the norm inequality on a Pseudo-hermitian manifold,
where the L^2 norm of all second derivatives of the function involving
horizontal derivatives is controlled by the L^2 norm of the sub-Laplacian.
Perturbation allows us to get a-priori bounds for solutions to sub-elliptic PDE
in non-divergence form with bounded measurable coefficients. The method of
proof is through a Bochner technique. The Heisenberg group is seen to be en
extremal manifold for our inequality in the class of manifolds whose Ricci
curvature is non-negative.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 15:21:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chanillo",
"Sagun",
""
],
[
"Manfredi",
"Juan J.",
""
]
] |
0704.2834 | Sundaram Thangavelu | S. Thangavelu | An analogue of Gutzmer's formula for Hermite expansions | 15 pages | null | null | null | math.CA math.FA | null | We prove an analogue of Gutzmer's formula for Hermite expansions. As a
consequence we obtain a new proof of a characterisation of the image of $
L^2(\R^n) $ under the Hermite semigroup. We also obtain some new orthogonality
relations for complexified Hermite functions.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 13:38:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Thangavelu",
"S.",
""
]
] |
0704.2835 | Qing-Guo Huang | Qing-Guo Huang | Simplified Chain Inflation | 8 pages, 1 figure; refs added | JCAP 0705:009,2007 | 10.1088/1475-7516/2007/05/009 | null | hep-th | null | We propose a simplified chain inflation model and calculate the primordial
power spectra of the scalar and tensor fluctuations. The spectral index and the
tensor-scalar ratio are respectively 0.972 and 0.089 which are consistent with
present cosmological observations.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 14:01:07 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Apr 2007 11:34:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Huang",
"Qing-Guo",
""
]
] |
0704.2836 | Edward Sion | Ryan T.Hamilton, Joel A. Urban, Edward M. Sion, Adric R. Riedel,
Elysse N. Voyer, John T. Marcy, Sarah L. Lakatos | An International Ultraviolet Explorer Archival Study of Dwarf Novae in
Outburst | Accepted for publication in the ApJ, Part 1 | null | 10.1086/519065 | null | astro-ph | null | We present a synthetic spectral analysis of nearly the entire far ultraviolet
International Ultraviolet Explorer (IUE) archive of spectra of dwarf novae in
or near outburst. The study includes 46 systems of all dwarf nova subtypes both
above and below the period gap. The spectra were uniformly analyzed using
synthetic spectral codes for optically thick accretion disks and stellar
photospheres along with the best-available distance measurements or estimates.
We present newly estimated accretion rates and discuss the implications of our
study for disk accretion physics and CV evolution.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 14:04:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hamilton",
"Ryan T.",
""
],
[
"Urban",
"Joel A.",
""
],
[
"Sion",
"Edward M.",
""
],
[
"Riedel",
"Adric R.",
""
],
[
"Voyer",
"Elysse N.",
""
],
[
"Marcy",
"John T.",
""
],
[
"Lakatos",
"Sarah L.",
""
]
] |
0704.2837 | Paul Clark Dr | Paul C. Clark, Ralf S. Klessen and Ian A. Bonnell | Clump Lifetimes and the Initial Mass Function | 7 pages, 3 figures, accepted to MNRAS | Mon.Not.Roy.Astron.Soc.379:57-62,2007 | 10.1111/j.1365-2966.2007.11896.x | null | astro-ph | null | Recent studies of dense clumps/cores in a number of regions of low-mass star
formation have shown that the mass distribution of these clumps closely
resembles the initial mass function (IMF) of field stars. One possible
interpretation of these observations is that we are witnessing the
fragmentation of the clouds into the IMF, and the observed clumps are bound
pre-stellar cores. In this paper, we highlight a potential difficulty in this
interpretation, namely that clumps of varying mass are likely to have
systematically varying lifetimes. This timescale problem can effectively
destroy the similarity bewteen the clump and stellar mass functions, such that
a stellar-like clump mass function (CMF) results in a much steeper stellar IMF.
We also discuss some ways in which this problem may be avoided.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 14:52:57 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Clark",
"Paul C.",
""
],
[
"Klessen",
"Ralf S.",
""
],
[
"Bonnell",
"Ian A.",
""
]
] |
0704.2838 | David Hernandez | David Hernandez | Kirillov-Reshetikhin conjecture : the general case | 81 pages, 4 figures. The Drinfeld-Serre relations are not used in the
proofs | Int. Math. Res. Not. 2010, no. 1, 149-193 | null | null | math.QA math.RT | null | We prove the Kirillov-Reshetikhin (KR) conjecture in the general case : for
all twisted quantum affine algebras we prove that the characters of KR modules
solve the twisted Q-system and we get explicit formulas for the character of
their tensor products (the untwisted simply-laced case was treated by Najakima,
and the untwisted case by the author). The proof is uniform and provides
several new developments for the representation theory of twisted quantum
affine algebras, including twisted Frenkel-Reshetikhin q-characters (expected
by Frenkel-Reshetikhin and Frenkel-Mukhin). We also prove the twisted T-system.
As an application we get explicit formulas for the twisted q-characters of
fundamental representations for all types, including the formulas for types
D_4^{(3)}, E_6^{(2)} conjectured by Reshetikhin. We prove the formulas for KR
modules in types A_n^{(2)} and D_4^{(3)} conjectured by Kuniba-Suzuki.
Eventually our results imply the conjectural branching rules [HKOTT] to the
quantum subalgebra of finite type.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 16:13:14 GMT"
},
{
"version": "v2",
"created": "Wed, 30 May 2007 20:58:21 GMT"
},
{
"version": "v3",
"created": "Wed, 13 Jun 2007 07:13:56 GMT"
}
] | 2010-04-07T00:00:00 | [
[
"Hernandez",
"David",
""
]
] |
0704.2839 | Reynier Peletier | Reynier F. Peletier (1), Jesus Falcon-Barroso (2,3), Roland Bacon (4),
Michele Cappellari (5,3), Roger L. Davies (5), P.T. de Zeeuw (3), Eric
Emsellem (4), Katia Ganda (1), Davor Krajnovic (5), Harald Kuntschner (6),
Richard M. McDermid (3), Marc Sarzi (7), Glenn van de Ven (8,3) ((1) Kapteyn
Institute, (2) ESTEC, (3) Sterrewacht Leiden, (4) Universite Lyon 1, CRAL (5)
Oxford, (6) ESO, (7) CfAR University of Hertfordshire, (8) IAS Princeton) | The SAURON project - XI. Stellar Populations from Absorption Line
Strength Maps of 24 Early-Type Spirals | Accepted for publication in MNRAS, 29 pages, 10 figures. Paper with
Figures at full resolution available at http://www.strw.leidenuniv.nl/sauron/ | Mon.Not.Roy.Astron.Soc.379:445-468,2007 | 10.1111/j.1365-2966.2007.11860.x | null | astro-ph | null | We present absorption line strength maps of a sample of 24 representative
early-type spiral galaxies, mostly of type Sa, obtained as part of the SAURON
survey of nearby galaxies using our custom-built integral-field spectrograph.
Using high-quality spectra, spatially binned to a constant signal-to-noise, we
measure several key age, metallicity and abundance ratio sensitive indices from
the Lick/IDS system over a contiguous two-dimensional field including bulge and
inner disc. We present maps of H beta, Fe 5015 and Mg b, for each galaxy
The absorption line maps show that many galaxies contain some younger
populations (<= 1 Gyr), distributed in small or large inner discs, or in
circumnuclear star forming rings. In many cases these young stars are formed in
circumnuclear mini-starbursts, which are dominating the light in the centres of
some of the early-type spirals. These mini-starburst cause a considerable
scatter in index-index diagrams such as Mg b- H beta and Mg b -Fe 5015, more
than is measured for early-type galaxies. We find that the central regions of
Sa galaxies display a wide range in ages, even within the galaxies. 50% of the
sample show velocity dispersion drops in their centres.
All of the galaxies of our sample lie on or below the Mg b- $\sigma$ relation
for elliptical galaxies in the Coma cluster, and above the H beta absorption
line - $\sigma$ relation for elliptical galaxies. If those relations are
considered to be relations for the oldest local galaxies we see that our sample
of spirals has a considerable scatter in age, with the largest scatter at the
lowest $\sigma$. This is in disagreement with highly inclined samples, in which
generally only old stellar populations are found in the central regions.
All this can be understood if ... (see paper for rest of abstract)
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 17:52:00 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 20:41:43 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Peletier",
"Reynier F.",
""
],
[
"Falcon-Barroso",
"Jesus",
""
],
[
"Bacon",
"Roland",
""
],
[
"Cappellari",
"Michele",
""
],
[
"Davies",
"Roger L.",
""
],
[
"de Zeeuw",
"P. T.",
""
],
[
"Emsellem",
"Eric",
""
],
[
"Ganda",
"Katia",
""
],
[
"Krajnovic",
"Davor",
""
],
[
"Kuntschner",
"Harald",
""
],
[
"McDermid",
"Richard M.",
""
],
[
"Sarzi",
"Marc",
""
],
[
"van de Ven",
"Glenn",
""
]
] |
0704.2840 | Damiano Anselmi | Damiano Anselmi and Anna Benini | Improved Schwinger-DeWitt techniques for higher-derivative perturbations
of operator determinants | 18 pages | JHEP0710:099,2007 | 10.1088/1126-6708/2007/10/099 | IFUP-TH 2007-8 | hep-th | null | We consider higher-derivative perturbations of quantum gravity and quantum
field theories in curved space and investigate tools to calculate counterterms
and short-distance expansions of Feynman diagrams. In the case of single
higher-derivative insertions we derive a closed formula that relates the
perturbed one-loop counterterms to the unperturbed Schwinger-DeWitt
coefficients. In the more general case, we classify the contributions to the
short-distance expansion and outline a number of simplification methods.
Certain difficulties of the common differential technique in the presence of
higher-derivative perturbations are avoided by a systematic use of the
Campbell-Baker-Hausdorff formula, which in some cases reduces the computational
effort considerably.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 16:30:14 GMT"
},
{
"version": "v2",
"created": "Fri, 2 Nov 2007 14:31:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Anselmi",
"Damiano",
""
],
[
"Benini",
"Anna",
""
]
] |
0704.2841 | Lun Dong | Athina P. Petropulu, Lun Dong, H. Vincent Poor | A High-Throughput Cross-Layer Scheme for Distributed Wireless Ad Hoc
Networks | 6 pages, Appeared in the Proceedings of the 41st Annual Conference on
Information Sciences and Systems, John Hopkins University, March 2007 | null | null | null | cs.IT math.IT | null | In wireless ad hoc networks, distributed nodes can collaboratively form an
antenna array for long-distance communications to achieve high energy
efficiency. In recent work, Ochiai, et al., have shown that such collaborative
beamforming can achieve a statistically nice beampattern with a narrow main
lobe and low sidelobes. However, the process of collaboration introduces
significant delay, since all collaborating nodes need access to the same
information. In this paper, a technique that significantly reduces the
collaboration overhead is proposed. It consists of two phases. In the first
phase, nodes transmit locally in a random access fashion. Collisions, when they
occur, are viewed as linear mixtures of the collided packets. In the second
phase, a set of cooperating nodes acts as a distributed antenna system and
beamform the received analog waveform to one or more faraway destinations. This
step requires multiplication of the received analog waveform by a complex
number, which is independently computed by each cooperating node, and which
enables separation of the collided packets based on their final destination.
The scheme requires that each node has global knowledge of the network
coordinates. The proposed scheme can achieve high throughput, which in certain
cases exceeds one.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 17:44:24 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Petropulu",
"Athina P.",
""
],
[
"Dong",
"Lun",
""
],
[
"Poor",
"H. Vincent",
""
]
] |
0704.2842 | Rafael G. Campos | Rafael G. Campos and Francisco Mejia | Quadrature formulas for the Laplace and Mellin transforms | 10 pages, 5 figures | null | null | null | math.NA | null | A discrete Laplace transform and its inversion formula are obtained by using
a quadrature of the continuous Fourier transform which is given in terms of
Hermite polynomials and its zeros. This approach yields a convergent discrete
formula for the two-sided Laplace transform if the function to be transformed
falls off rapidly to zero and satisfy certain conditions of integrability,
achieving convergence also for singular functions. The inversion formula
becomes a quadrature formula for the Bromwich integral. This procedure also
yields a quadrature formula for the Mellin transform and its corresponding
inversion formula that can be generalized straightforwardly for functions of
several variables.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 17:55:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Campos",
"Rafael G.",
""
],
[
"Mejia",
"Francisco",
""
]
] |
0704.2843 | Marcus Pinto B | Jean-Loic Kneur, Marcus Benghi Pinto and Rudnei O. Ramos | The 2d Gross-Neveu Model at Finite Temperature and Density with Finite
Corrections | 7 pages, 8 figures | Braz.J.Phys.37:258-264,2007 | 10.1590/S0103-97332007000200016 | null | hep-ph cond-mat.other hep-th | null | We use the linear $\delta$ expansion, or optimized perturbation theory, to
evaluate the effective potential for the two dimensional Gross-Neveu model at
finite temperature and density obtaining analytical equations for the critical
temperature, chemical potential and fermionic mass which include finite $N$
corrections. Our results seem to improve over the traditional large-N
predictions.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 18:17:53 GMT"
}
] | 2011-08-04T00:00:00 | [
[
"Kneur",
"Jean-Loic",
""
],
[
"Pinto",
"Marcus Benghi",
""
],
[
"Ramos",
"Rudnei O.",
""
]
] |
0704.2844 | Omer Friedland | Omer Friedland | Kahane-Khinchin type Averages | null | null | null | null | math.FA | null | We prove a Kahane-Khinchin type result with a few random vectors, which are
distributed independently with respect to an arbitrary log-concave probability
measure on $\R^n$. This is an application of small ball estimate and Chernoff's
method, that has been recently used in the context of Asymptotic Geometric
Analysis in [1], [2].
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 18:45:43 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Sep 2007 15:25:56 GMT"
}
] | 2007-09-10T00:00:00 | [
[
"Friedland",
"Omer",
""
]
] |
0704.2845 | Csaba Schneider | Csaba Schneider and Hendrik Van Maldeghem | Primitive flag-transitive generalized hexagons and octagons | forgot to upload the appendices in version 1, and this is rectified
in version 2. erased cross-ref keys in version 3. Minor revision in version 4
to implement the suggestion by the referee (new section at the end, extended
acknowledgment, simpler proof for Lemma 4.2) | null | null | null | math.CO math.GR | null | Suppose that an automorphism group $G$ acts flag-transitively on a finite
generalized hexagon or octagon $\cS$, and suppose that the action on both the
point and line set is primitive. We show that $G$ is an almost simple group of
Lie type, that is, the socle of $G$ is a simple Chevalley group.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 19:12:03 GMT"
},
{
"version": "v2",
"created": "Fri, 14 Mar 2008 12:35:16 GMT"
}
] | 2008-03-14T00:00:00 | [
[
"Schneider",
"Csaba",
""
],
[
"Van Maldeghem",
"Hendrik",
""
]
] |
0704.2846 | \'Angel R. L\'opez-S\'anchez Dr. | \'Angel R. L\'opez-S\'anchez and C\'esar Esteban (Instituto de
Astrof\'isica de Canarias, IAC, SPAIN) | Interactions and star formation activity in Wolf-Rayet galaxies | 16 pages, 15 figures | Astrophys.Space Sci.324:355-359,2009 | 10.1007/s10509-009-0154-z | null | astro-ph | null | We present the main results of the PhD Thesis carried out by
L\'opez-S\'anchez (2006), in which a detailed morphological, photometrical and
spectroscopical analysis of a sample of 20 Wolf-Rayet (WR) galaxies was
realized. The main aims are the study of the star formation and O and WR
stellar populations in these galaxies and the role that interactions between
low surface companion objects have in the triggering of the bursts. We analyze
the morphology, stellar populations, physical conditions, chemical abundances
and kinematics of the ionized gas, as well as the star-formation activity of
each system.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 18:52:58 GMT"
}
] | 2016-08-14T00:00:00 | [
[
"López-Sánchez",
"Ángel R.",
"",
"Instituto de\n Astrofísica de Canarias, IAC, SPAIN"
],
[
"Esteban",
"César",
"",
"Instituto de\n Astrofísica de Canarias, IAC, SPAIN"
]
] |
0704.2847 | Seth Sullivant | Seth Sullivant | Gaussian conditional independence relations have no finite complete
characterization | 6 pages | null | null | null | math.PR math.AC | null | We show that there can be no finite list of conditional independence
relations which can be used to deduce all conditional independence implications
among Gaussian random variables. To do this, we construct, for each $n> 3$ a
family of $n$ conditional independence statements on $n$ random variables which
together imply that $X_1 \ind X_2$, and such that no subset have this same
implication. The proof relies on binomial primary decomposition.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 19:47:05 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sullivant",
"Seth",
""
]
] |
0704.2848 | Alexander Polishchuk | Alexander Polishchuk | Algebraic cycles on the relative symmetric powers and on the relative
Jacobian of a family of curves. I | 31 pages, uses Paul Taylor's diagrams.sty. Added in v2: construction
of a new grading on the algebra of 0-cycles on the Jacobian and of an action
of the Lie algebra of vector fields on it. v3: some typos corrected, to
appear in Selecta Math | null | null | null | math.AG | null | In this paper we construct and study the actions of certain deformations of
the Lie algebra of Hamiltonians on the plane on the Chow groups (resp.,
cohomology) of the relative symmetric powers ${\cal C}^{[\bullet]}$ and the
relative Jacobian ${\cal J}$ of a family of curves ${\cal C}/S$. As one of the
applications, we show that in the case of a single curve $C$ this action
induces a integral form of a Lefschetz $\operatorname{sl}_2$-action on the Chow
groups of $C^{[N]}$. Another application gives a new grading on the ring of
0-cycles on the Jacobian $J$ of $C$ (with respect to the Pontryagin product)
and equips it with an action of the Lie algebra of vector fields on the line.
We also define the groups of tautological classes in $CH^*({\cal
C}^{[\bullet]})$ and in $CH^*({\cal J})$ and prove for them analogs of the
properties established in the case of the Jacobian of a single curve by
Beauville in math.AG/0204188. We also show that the our algebras of operators
preserve the subrings of tautological cycles and act on them via some explicit
differential operators.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 20:30:59 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Apr 2007 00:09:44 GMT"
},
{
"version": "v3",
"created": "Wed, 5 Mar 2008 04:51:30 GMT"
}
] | 2008-03-05T00:00:00 | [
[
"Polishchuk",
"Alexander",
""
]
] |
0704.2849 | H. Blaine Lawson Jr. | Blaine Lawson and John Wermer | On the Complement of the Projective Hull in C^n | null | null | null | null | math.CV math.DG | null | We prove that if $K$ is a compact subset of an affine variety O = P^n - D
(where D is a projective hypersuface), and if K is a compact subset of a closed
analytic subvariety V \subset O, then the projective hull K^ of K has the
property that K^ \cap O is contained in V. If V is smooth and 1-dimensional,
then K^ \cap O is also closed in O. The result has applications to graphs in
C^2 of functions in the disk algebra.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 20:18:28 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lawson",
"Blaine",
""
],
[
"Wermer",
"John",
""
]
] |
0704.2850 | Tom Chang | Tom Chang and Cheng-chin Wu | Dynamical Complexity, Intermittent Turbulence, Coarse-Grained
Dissipation, Criticality and Multifractal Processes | 6 pages, 2 figures, submitted to AIP Conference Proceedings for the
6th Annual International Astrophysics Conference, Honolulu, March 16-22, 2007 | AIP Conf.Proc.932:161-166,2007 | 10.1063/1.2778959 | null | astro-ph | null | The ideas of dynamical complexity induced intermittent turbulence by sporadic
localized interactions of coherent structures are discussed. In particular, we
address the phenomenon of magnetic reconfiguration due to coarse-grained
dissipation as well as the interwoven connection between criticality and
multifractal processes. Specific examples are provided.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 20:51:53 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Chang",
"Tom",
""
],
[
"Wu",
"Cheng-chin",
""
]
] |
0704.2851 | Gabriel Sanchez-Colon | S.Chaturvedi, V.Gupta, and G.Sanchez-Colon | Bounds on quark mass matrices elements due to measured properties of the
mixing matrix and present values of the quark masses | Evolution effects included | Int.J.Mod.Phys.A23:1729-1746,2008 | 10.1142/S0217751X0803975X | null | hep-ph | null | We obtain constraints on possible structures of mass matrices in the quark
sector by using as experimental restrictions the determined values of the quark
masses at the $M_Z$ energy scale, the magnitudes of the quark mixing matrix
elements $V_{\rm ud}$, $V_{\rm us}$, $V_{\rm cd}$, and $V_{\rm cs}$, and the
Jarlskog invariant $J(V)$. Different cases of specific mass matrices are
examined in detail. The quality of the fits for the Fritzsch and Stech type
mass matrices is about the same with $\chi^2/{\rm dof}=4.23/3=1.41$ and
$\chi^2/{\rm dof}=9.10/4=2.28$, respectively. The fit for a simple
generalization (one extra parameter) of the Fritzsch type matrices, in the
physical basis, is much better with $\chi^2/{\rm dof}=1.89/4=0.47$. For
comparison we also include the results using the quark masses at the 2 GeV
energy scale. The fits obtained at this energy scale are similar to that at
$M_Z$ energy scale, implying that our results are unaffected by the evolution
of the quark masses from 2 to 91 GeV.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 21:14:24 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Feb 2008 19:50:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chaturvedi",
"S.",
""
],
[
"Gupta",
"V.",
""
],
[
"Sanchez-Colon",
"G.",
""
]
] |
0704.2852 | Christof Teuscher | Christof Teuscher | Nature-Inspired Interconnects for Self-Assembled Large-Scale
Network-on-Chip Designs | null | Chaos, 17(2):026106, 2007 | 10.1063/1.2740566 | LA-UR-07-0204 | cs.AR cond-mat.dis-nn nlin.AO | null | Future nano-scale electronics built up from an Avogadro number of components
needs efficient, highly scalable, and robust means of communication in order to
be competitive with traditional silicon approaches. In recent years, the
Networks-on-Chip (NoC) paradigm emerged as a promising solution to interconnect
challenges in silicon-based electronics. Current NoC architectures are either
highly regular or fully customized, both of which represent implausible
assumptions for emerging bottom-up self-assembled molecular electronics that
are generally assumed to have a high degree of irregularity and imperfection.
Here, we pragmatically and experimentally investigate important design
trade-offs and properties of an irregular, abstract, yet physically plausible
3D small-world interconnect fabric that is inspired by modern network-on-chip
paradigms. We vary the framework's key parameters, such as the connectivity,
the number of switch nodes, the distribution of long- versus short-range
connections, and measure the network's relevant communication characteristics.
We further explore the robustness against link failures and the ability and
efficiency to solve a simple toy problem, the synchronization task. The results
confirm that (1) computation in irregular assemblies is a promising and
disruptive computing paradigm for self-assembled nano-scale electronics and (2)
that 3D small-world interconnect fabrics with a power-law decaying distribution
of shortcut lengths are physically plausible and have major advantages over
local 2D and 3D regular topologies.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 21:26:03 GMT"
}
] | 2007-07-01T00:00:00 | [
[
"Teuscher",
"Christof",
""
]
] |
0704.2853 | In Yong Park | I. Y. Park | Toward getting finite results from N=4 SYM with alpha'-corrections | 13 pages, 3 figures, appendices shortened, typos corrected, refs
added | null | null | null | hep-th | null | We take our first step toward getting finite results from the
alpha'-corrected D=4 N=4 SYM theory with emphasis on the field theory
techniques. Starting with the classical action of N=4 SYM with the leading
alpha'-corrections, we examine new divergence at one loop due to the presence
of the alpha'-terms. The new vertices do not introduce additional divergence to
the propagators or to the three-point correlators. However they do introduce
new divergence, e.g., to the scalar four-point function which should be
canceled by extra counter-terms. We expect that the counter-terms will appear
in the 1PI effective action that is obtained by considering the string annulus
diagram. We work out the structure of the divergence and comment on an
application to the anomalous dimension of the SYM operators in the context of
AdS/CFT.
| [
{
"version": "v1",
"created": "Sat, 21 Apr 2007 22:54:41 GMT"
},
{
"version": "v2",
"created": "Sun, 29 Apr 2007 13:46:21 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Park",
"I. Y.",
""
]
] |
0704.2854 | David J. Dean | G. Hagen, T. Papenbrock, D.J. Dean, A. Schwenk, A. Nogga, M. Wloch,
and P. Piecuch | Coupled-cluster theory for three-body Hamiltonians | 12 pages, 9 figures | Phys.Rev.C76:034302,2007 | 10.1103/PhysRevC.76.034302 | null | nucl-th | null | We derive coupled-cluster equations for three-body Hamiltonians. The
equations for the one- and two-body cluster amplitudes are presented in a
factorized form that leads to an efficient numerical implementation. We employ
low-momentum two- and three-nucleon interactions and calculate the binding
energy of He-4. The results show that the main contribution of the
three-nucleon interaction stems from its density-dependent zero-, one-, and
two-body terms that result from the normal ordering of the Hamiltonian in
coupled-cluster theory. The residual three-body terms that remain after normal
ordering can be neglected.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 16:56:18 GMT"
},
{
"version": "v2",
"created": "Fri, 7 Sep 2007 21:05:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hagen",
"G.",
""
],
[
"Papenbrock",
"T.",
""
],
[
"Dean",
"D. J.",
""
],
[
"Schwenk",
"A.",
""
],
[
"Nogga",
"A.",
""
],
[
"Wloch",
"M.",
""
],
[
"Piecuch",
"P.",
""
]
] |
0704.2855 | Klaus Capelle | E. Orestes, K. Capelle, A. B. F. da Silva and C. A. Ullrich | The generator coordinate method in time-dependent density-functional
theory: memory made simple | 10 pages, 13 figures | J. Chem. Phys. 127, 124101 (2007) | 10.1063/1.2768368 | null | cond-mat.mes-hall cond-mat.mtrl-sci physics.chem-ph | null | The generator coordinate (GC) method is a variational approach to the quantum
many-body problem in which interacting many-body wave functions are constructed
as superpositions of (generally nonorthogonal) eigenstates of auxiliary
Hamiltonians containing a deformation parameter. This paper presents a
time-dependent extension of the GC method as a new approach to improve existing
approximations of the exchange-correlation (XC) potential in time-dependent
density-functional theory (TDDFT). The time-dependent GC method is shown to be
a conceptually and computationally simple tool to build memory effects into any
existing adiabatic XC potential. As an illustration, the method is applied to
driven parametric oscillations of two interacting electrons in a harmonic
potential (Hooke's atom). It is demonstrated that a proper choice of
time-dependent generator coordinates in conjunction with the adiabatic
local-density approximation reproduces the exact linear and nonlinear
two-electron dynamics quite accurately, including features associated with
double excitations that cannot be captured by TDDFT in the adiabatic
approximation.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 17:07:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Orestes",
"E.",
""
],
[
"Capelle",
"K.",
""
],
[
"da Silva",
"A. B. F.",
""
],
[
"Ullrich",
"C. A.",
""
]
] |
0704.2856 | Immanuel Bloch | Torben Mueller, Simon Foelling, Artur Widera, Immanuel Bloch | State preparation and dynamics of ultracold atoms in higher lattice
orbitals | 4 pages, 4 figures | Phys. Rev. Lett. 99, 200405 (2007) | 10.1103/PhysRevLett.99.200405 | null | cond-mat.other cond-mat.str-el | null | We report on the realization of a multi-orbital system with ultracold atoms
in the excited bands of a 3D optical lattice by selectively controlling the
band population along a given lattice direction. The lifetime of the atoms in
the excited band is found to be considerably longer (10-100 times) than the
characteristic time scale for inter-site tunneling, thus opening the path for
orbital selective many-body physics with ultracold atoms. Upon exciting the
atoms from an initial lowest band Mott insulating state to higher lying bands,
we observe the dynamical emergence of coherence in 1D (and 2D), compatible with
Bose-Einstein condensation to a non-zero momentum state.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 00:21:54 GMT"
}
] | 2008-04-23T00:00:00 | [
[
"Mueller",
"Torben",
""
],
[
"Foelling",
"Simon",
""
],
[
"Widera",
"Artur",
""
],
[
"Bloch",
"Immanuel",
""
]
] |
0704.2857 | Andrea Montanari | Andrea Montanari and Rudiger Urbanke | Modern Coding Theory: The Statistical Mechanics and Computer Science
Point of View | Lectures at Les Houches Summer School on `Complex Systems', July
2006, 44 pages, 25 ps figures | null | null | null | cs.IT cond-mat.stat-mech math.IT | null | These are the notes for a set of lectures delivered by the two authors at the
Les Houches Summer School on `Complex Systems' in July 2006. They provide an
introduction to the basic concepts in modern (probabilistic) coding theory,
highlighting connections with statistical mechanics. We also stress common
concepts with other disciplines dealing with similar problems that can be
generically referred to as `large graphical models'.
While most of the lectures are devoted to the classical channel coding
problem over simple memoryless channels, we present a discussion of more
complex channel models. We conclude with an overview of the main open
challenges in the field.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 01:57:03 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Montanari",
"Andrea",
""
],
[
"Urbanke",
"Rudiger",
""
]
] |
0704.2858 | Yusuke Sasano | Yusuke Sasano | Double covering of the Painlev\'e I equation and its singular analysis | 18 pages, 4 figures | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note, we will do analysis of accessible singular points for a
polynomial Hamiltonian system obtained by taking a double covering of the
Painlev\'e I equation. We will show that this system passes the Painlev\'e
$\alpha$-test for all accessible singular points $P_i \ (i=1,2,3)$. We note its
holomorphy condition of the first Painlev\'e system.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 03:56:12 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Apr 2007 18:09:20 GMT"
},
{
"version": "v3",
"created": "Fri, 27 Apr 2007 15:53:56 GMT"
},
{
"version": "v4",
"created": "Sun, 29 Apr 2007 05:55:44 GMT"
},
{
"version": "v5",
"created": "Sun, 13 May 2007 17:19:22 GMT"
},
{
"version": "v6",
"created": "Wed, 3 Nov 2010 06:08:15 GMT"
},
{
"version": "v7",
"created": "Thu, 5 May 2016 11:39:03 GMT"
},
{
"version": "v8",
"created": "Fri, 13 May 2016 23:12:41 GMT"
}
] | 2016-05-17T00:00:00 | [
[
"Sasano",
"Yusuke",
""
]
] |
0704.2859 | Barak Dayan | Barak Dayan | Theory of Two-Photon Interactions with Broadband Down-Converted Light
and Entangled Photons | 23 pages, 4 figures, submitted to Phys. Rev. A | null | 10.1103/PhysRevA.76.043813 | null | quant-ph | null | When two-photon interactions are induced by down-converted light with a
bandwidth that exceeds the pump bandwidth, they can obtain a behavior that is
pulse-like temporally, yet spectrally narrow. At low photon fluxes this
behavior reflects the time and energy entanglement between the down-converted
photons. However, two-photon interactions such as two-photon absorption (TPA)
and sum-frequency generation (SFG) can exhibit such a behavior even at high
power levels, as long as the final state (i.e. the atomic level in TPA, or the
generated light in SFG) is narrowband enough. This behavior does not depend on
the squeezing properties of the light, is insensitive to linear losses, and has
potential applications. In this paper we describe analytically this behavior
for travelling-wave down-conversion with continuous or pulsed pumping, both for
high- and low-power regimes. For this we derive a quantum-mechanical expression
for the down-converted amplitude generated by an arbitrary pump, and formulate
operators that represent various two-photon interactions induced by broadband
light. This model is in excellent agreement with experimental results of TPA
and SFG with high power down-converted light and with entangled photons [Dayan
et al., Phys. Rev. Lett. 93, 023005 (2004), Dayan et al., Phys. Rev. Lett. 94,
043602, (2005), Pe'er et al., Phys. Rev. Lett. 94, 073601 (2005)].
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 04:02:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dayan",
"Barak",
""
]
] |
0704.2860 | Robert Kurucz | Robert L. Kurucz | Cryptoplanet update | research presentation, 85 figures | null | null | null | astro-ph | null | We have had several talks recently reviewing 11 years of exoplanet
discoveries through radial velocity variations, or from transits, or from
microlensing. More than 200 exoplanets have been found, including some around
pulsars that we do not discuss here.
My physical definition for a planet is a roughly spherical, self-gravitating
body more massive than 10**26 g formed from the leftover material in a
protostellar disk after the protostar forms. Radiation from the protostar
pushes the inner wall of the disk outward. The material agglomerates and forms
planets in radial sequence. The outer planets are formed slowly by classical
dynamical mechanisms acting in the snow zone. Planets have dense cores because
of agglomeration.
Not one of the exoplanets discovered thus far is a planet. They are
cryptoplanets formed from matter ejected by protostars. When protostars have
excessive infall at high latitudes, they partially balance angular momentum
through outflow at the equator as they spin up. The ejected matter is trapped
in the magnetic torus formed between the star and the disk, like a tokamak. The
tokamak eventully reconnects and magnetic compression forms self-gravitating
remnants trapped and compressed by a closed spherical magnetic field,
spheromaks. Cooled spheromaks are cryptoplanets. They orbit near the star. They
can merge with each other or fall into the star or be ejected. They can grow by
accreting gas. They have a low density core and abundances characteristic of
the protostar. Their masses, radii, densities, and orbits are random, and are
inconsistent with the parameters for planets. They tend to have lower density
than planets.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 04:02:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kurucz",
"Robert L.",
""
]
] |
0704.2861 | Vasileios Paschalidis | Vasileios Paschalidis | Mixed Hyperbolic - Second-Order Parabolic Formulations of General
Relativity | 19 pages, two column, references added, two proofs of well-posedness
added, content changed to agree with submitted version to PRD | Phys.Rev.D78:024002,2008 | 10.1103/PhysRevD.78.024002 | null | gr-qc | null | Two new formulations of general relativity are introduced. The first one is a
parabolization of the Arnowitt, Deser, Misner (ADM) formulation and is derived
by addition of combinations of the constraints and their derivatives to the
right-hand-side of the ADM evolution equations. The desirable property of this
modification is that it turns the surface of constraints into a local attractor
because the constraint propagation equations become second-order parabolic
independently of the gauge conditions employed. This system may be classified
as mixed hyperbolic - second-order parabolic. The second formulation is a
parabolization of the Kidder, Scheel, Teukolsky formulation and is a manifestly
mixed strongly hyperbolic - second-order parabolic set of equations, bearing
thus resemblance to the compressible Navier-Stokes equations. As a first test,
a stability analysis of flat space is carried out and it is shown that the
first modification exponentially damps and smoothes all constraint violating
modes. These systems provide a new basis for constructing schemes for long-term
and stable numerical integration of the Einstein field equations.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 20:06:57 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Mar 2008 02:29:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Paschalidis",
"Vasileios",
""
]
] |
0704.2862 | Alexander Khitun | Alexander Khitun, Dmitri E. Nikonov, Mingqiang Bao, Kosmas Galatsis,
and Kang L. Wang | Feasibility Study of Logic Circuits with Spin Wave Bus | null | null | 10.1088/0957-4484/18/46/465202 | null | cond-mat.other | null | We present a feasibility study of logic circuits utilizing spin waves for
information transmission and processing. As an alternative approach to the
transistor-based architecture, logic circuits with spin wave bus do not use
charge as an information carrier. In this work we describe the general concept
of logic circuits with spin wave bus and illustrate its performance by
numerical simulations based on available experimental data. Theoretical
estimates and results of numerical simulations on signal attenuation, signal
phase velocity, and the minimum spin wave energy required per bit in the spin
bus are obtained. The transport parameters are compared with ones for
conventional electronic transmission lines. Spin Wave Bus is not intended to
substitute traditional metal interconnects since it has higher signal
attenuation and lower signal propagation speed. The potential value of spin
wave bus is, however, an interface between electronic circuits and integrated
spintronics circuits. The logic circuits with spin wave bus allow us to provide
wireless read-in and read-out.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 17:38:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Khitun",
"Alexander",
""
],
[
"Nikonov",
"Dmitri E.",
""
],
[
"Bao",
"Mingqiang",
""
],
[
"Galatsis",
"Kosmas",
""
],
[
"Wang",
"Kang L.",
""
]
] |
0704.2863 | Yusuke Sasano | Yusuke Sasano | On some Hamiltonian structures of coupled Painlev\'e II systems in
dimension four | 9 pages | null | null | null | math.AG math-ph math.CA math.DS math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We find and study a two-parameter family of coupled Painlev\'e II systems in
dimension four with affine Weyl group symmetry of several types. Moreover, we
find a three-parameter family of polynomial Hamiltonian systems in two
variables $t,s$. Setting $s=0$, we can obtain an autonomous version of the
coupled Painlev\'e II systems. We also show its symmetry and holomorphy
conditions.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 06:49:15 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Jan 2011 14:20:24 GMT"
}
] | 2011-01-07T00:00:00 | [
[
"Sasano",
"Yusuke",
""
]
] |
0704.2864 | K.G. Suresh | Pramod Kumar, K. G. Suresh and A. K. Nigam | Sm2Al: Another ferromagnet with spin-orbital compensation? | 12 oages | null | null | null | cond-mat.mtrl-sci cond-mat.other | null | We report the observation of a compensation point in the temperature
dependence of magnetization data of polycrystalline Sm2Al. Magnetization
measurements show that this compound magnetically orders at about 150 K. Below
this temperature, the magnetization data shows a compensation point, which
shifts with field. Hysteresis loops obtained below the compensation temperature
show that the compound possesses exchange anisotropy. Both the exchange
anisotropy field and the coercive field are found to be quite large and
comparable to those of the classical spin-orbit compensated ferromagnet
(Sm,Gd)Al2. The heat capacity data also suggest that there are similarities
between (Sm,Gd)Al2 and Sm2Al.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 06:49:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kumar",
"Pramod",
""
],
[
"Suresh",
"K. G.",
""
],
[
"Nigam",
"A. K.",
""
]
] |
0704.2865 | Andrei Khrennikov | Andrei Khrennikov | Classical and quantum randomness and the financial market | null | null | null | Chapter in: A. Khrennikov, Ubiquitous quantum structure: from
psychology to finances, Springer, Berlin-Heidelberg-New York, 2010 | q-fin.ST math-ph math.MP math.PR | null | We analyze complexity of financial (and general economic) processes by
comparing classical and quantum-like models for randomness. Our analysis
implies that it might be that a quantum-like probabilistic description is more
natural for financial market than the classical one. A part of our analysis is
devoted to study the possibility of application of the quantum probabilistic
model to agents of financial market. We show that, although the direct quantum
(physical) reduction (based on using the scales of quantum mechanics) is
meaningless, one may apply so called quantum-like models. In our approach
quantum-like probabilistic behaviour is a consequence of contextualy of
statistical data in finances (and economics in general). However, our
hypothesis on "quantumness" of financial data should be tested experimentally
(as opposed to the conventional description based on the noncontextual
classical probabilistic approach). We present a new statistical test based on a
generalization of the well known in quantum physics Bell's inequality.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 08:26:27 GMT"
}
] | 2014-03-13T00:00:00 | [
[
"Khrennikov",
"Andrei",
""
]
] |
0704.2866 | Kimiko Yamada | Kimiko Yamada | A sequence of blowing-ups connecting moduli of sheaves and the Donaldson
polynomial under change of polarization | This article has been published, while Introduction is revised | J. Math. Kyoto Univ. 43 (2003) no.4, 829-878 | null | null | math.AG | null | Let $H$ and $H'$ be two ample line bundles over a nonsingular projective
surface $X$, and $M(H)$ (resp. $M(H')$) the coarse moduli scheme of
$H$-semistable (resp. $H'$-semistable) sheaves of fixed type $(r=2,c_1,c_2)$.
In a moduli-theoretic way that comes from elementary transforms, we connect
$M(H)$ and $M(H')$ by a sequence of blowing-ups when walls separating $H$ and
$H'$ are not necessarily good. As an application, we also consider the
polarization change problem of Donaldson polynomials.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 08:39:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yamada",
"Kimiko",
""
]
] |
0704.2867 | Eran Bouchbinder | Eran Bouchbinder, Michal Bregman and Itamar Procaccia | On the Self-Affine Roughness of a Crack Front in Heterogeneous Media | 4 pages, 4 figures | Phys. Rev. E 76, 025101(R) (2007) | 10.1103/PhysRevE.76.025101 | null | cond-mat.dis-nn cond-mat.mtrl-sci | null | The long-ranged elastic model, which is believed to describe the evolution of
a self-affine rough crack-front, is analyzed to linear and non-linear orders.
It is shown that the nonlinear terms, while important in changing the front
dynamics, are not changing the scaling exponent which characterizes the
roughness of the front. The scaling exponent thus predicted by the model is
much smaller than the one observed experimentally. The inevitable conclusion is
that the gap between the results of experiments and the model that is supposed
to describe them is too large, and some new physics has to be invoked for
another model.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 09:16:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bouchbinder",
"Eran",
""
],
[
"Bregman",
"Michal",
""
],
[
"Procaccia",
"Itamar",
""
]
] |
0704.2868 | Jing Qin | Christian M. Reidys | Large components in random induced subgraphs of n-cubes | 18 Pages | null | null | null | math.CO math.PR | null | In this paper we study random induced subgraphs of the binary $n$-cube,
$Q_2^n$. This random graph is obtained by selecting each $Q_2^n$-vertex with
independent probability $\lambda_n$. Using a novel construction of
subcomponents we study the largest component for
$\lambda_n=\frac{1+\chi_n}{n}$, where $\epsilon\ge \chi_n\ge n^{-{1/3}+
\delta}$, $\delta>0$. We prove that there exists a.s. a unique largest
component $C_n^{(1)}$. We furthermore show that $\chi_n=\epsilon$, $|
C_n^{(1)}|\sim \alpha(\epsilon) \frac{1+\chi_n}{n} 2^n$ and for $o(1)=\chi_n\ge
n^{-{1/3}+\delta}$, $| C_n^{(1)}| \sim 2 \chi_n \frac{1+\chi_n}{n} 2^n$ holds.
This improves the result of \cite{Bollobas:91} where constant $\chi_n=\chi$ is
considered. In particular, in case of $\lambda_n=\frac{1+\epsilon} {n}$, our
analysis implies that a.s. a unique giant component exists.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 09:20:01 GMT"
},
{
"version": "v2",
"created": "Fri, 1 Feb 2008 02:51:39 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Mar 2008 02:45:24 GMT"
}
] | 2008-03-07T00:00:00 | [
[
"Reidys",
"Christian M.",
""
]
] |
0704.2869 | Yusuke Sasano | Yusuke Sasano | Studies on the Garnier system in two variables | 31 pages, 8 figures | null | null | null | math.AG | null | We study some Hamiltonian structures of the Garnier system in two variables
from the viewpoints of its symmetry and holomorphy properties. We also give a
generalization of {\it Okamoto transformation \it}of the sixth Painlev\'e
system.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 09:39:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sasano",
"Yusuke",
""
]
] |
0704.2870 | Kimiko Yamada | Kimiko Yamada | Blowing-ups describing the polarization change of moduli schemes of
semistable sheaves of general rank | null | null | null | null | math.AG | null | Let $H$ and $H'$ be two ample line bundles over a smooth projective surface
$X$, and $M(H)$ (resp. $M(H')$) the coarse moduli scheme of $H$-semistable
(resp. $H'$-semistable) sheaves of fixed type $(r,c_1,c_2)$. We construct a
sequence of blowing-ups which describes how $M(H)$ differs from $M(H')$ not
only when $r=2$ but also when $r$ is arbitrary. Means we here utilize are
elementary transforms and the notion of a sheaf with flag.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 09:42:05 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yamada",
"Kimiko",
""
]
] |
0704.2871 | Mark Agranovsky | Mark Agranovsky | Complex dimensions of real manifolds, attached analytic discs and
parametric argument principle | null | null | null | null | math.CV | null | Let $\Omega$ be a smooth real analytic submanifold of a complex manifold $X$.
We establish and study the link between the following 3 subjects: 1)
topological properties of smooth families of attached analytic discs, the
manifold $\Omega$ admits, 2) lower bounds for dimensions of complex tangent
spaces of $\Omega$, 3) a generalization of the argument principle for smooth
families of holomorphic mappings from the standard complex disc to $X$.
In particular, we obtain characterization of complex manifolds and their
boundaries in terms of attached analytic discs. The special case when $\Omega$
is the graph, leads to new characterizations of holomorphic and $CR$ functions,
and in particular, to solutions of some open problems about such functions.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 12:14:09 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Sep 2007 14:11:23 GMT"
}
] | 2007-09-05T00:00:00 | [
[
"Agranovsky",
"Mark",
""
]
] |
0704.2872 | Alberto Sesana | A. Sesana, F. Haardt, P. Madau | Hypervelocity stars and the environment of Sgr A* | 5 pages, 5 figures, accepted for publication in MNRAS letters | Mon.Not.Roy.Astron.Soc.Lett.379:L45-L49,2007 | 10.1111/j.1745-3933.2007.00331.x | null | astro-ph | null | Hypervelocity stars (HVSs) are a natural consequence of the presence of a
massive nuclear black hole (Sgr A*) in the Galactic Center. Here we use the
Brown et al. sample of unbound and bound HVSs together with numerical
simulations of the propagation of HVSs in the Milky Way halo to constrain three
plausible ejection mechanisms: 1) the scattering of stars bound to Sgr A* by an
inspiraling intermediate-mass black hole (IMBH); 2) the disruption of stellar
binaries in the tidal field of Sgr A*; and 3) the two-body scattering of stars
off a cluster of stellar-mass black holes orbiting Sgr A*. We compare the
predicted radial and velocity distributions of HVSs with the limited-statistics
dataset currently available, and show that the IMBH model appears to produce a
spectrum of ejection velocities that is too flat. Future astrometric and deep
wide-field surveys of HVSs should shed unambiguous light on the stellar
ejection mechanism and probe the Milky Way potential on scales as large as 200
kpc.
| [
{
"version": "v1",
"created": "Mon, 23 Apr 2007 17:25:44 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Apr 2007 10:39:35 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Sesana",
"A.",
""
],
[
"Haardt",
"F.",
""
],
[
"Madau",
"P.",
""
]
] |
0704.2873 | Yusuke Sasano | Yusuke Sasano | Coupled Painlev\'e III system with affine Weyl group symmetry of type
$D_6^{(1)}$ | 16 pages, 2 figures | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We find and study a six-parameter family of coupled Painlev\'e III systems in
dimension six with affine Weyl group symmetry of type $D_6^{(1)}$. We also find
and study its degenerate systems with affine Weyl group symmetry of types
$B_5^{(1)}$ and $D_5^{(2)}$.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 10:29:54 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Nov 2009 13:07:06 GMT"
}
] | 2009-11-02T00:00:00 | [
[
"Sasano",
"Yusuke",
""
]
] |
0704.2874 | Sergey Tsygankov | S.S. Tsygankov (1,2), A.A. Lutovinov (1,2), E.M. Churazov (2,1), R.A.
Sunyaev (2,1) ((1) Space Research Institute, Moscow, Russia; (2) MPI for
Astrophysik, Garching, Germany) | 4U 0115+63 from RXTE and INTEGRAL Data: Pulse Profile and Cyclotron Line
Energy | 30 pages, 13 figures, Astronomy Letters, 33, 368 (2007) | Astron.Lett.33:368-384,2007; Pisma Astron.Zh.33:417-434,2007 | 10.1134/S1063773707060023 | null | astro-ph | null | We analyze the observations of the transient X-ray pulsar 4U 0115+63 with the
RXTE and INTEGRAL observatories in a wide X-ray (3-100 keV) energy band during
its intense outbursts in 1999 and 2004. The energy of the fundamental harmonic
of the cyclotron resonance absorption line near the maximum of the X-ray flux
from the source (luminosity range 5x10^{37} - 2x10^{38} erg/s) is ~11 keV. When
the pulsar luminosity falls below ~5x10^{37} erg/s, the energy of the
fundamental harmonic is displaced sharply toward the high energies, up to ~16
keV. Under the assumption of a dipole magnetic field configuration, this change
in cyclotron harmonic energy corresponds to a decrease in the height of the
emitting region by ~2 km, while other spectral parameters, in particular, the
cutoff energy, remain essentially constant. At a luminosity ~7x10^{37} erg/s,
four almost equidistant cyclotron line harmonics are clearly seen in the
spectrum. This suggests that either the region where the emission originates is
compact or the emergent spectrum from different (in height) segments of the
accretion column is uniform. We have found significant pulse profile variations
with energy, luminosity, and time. In particular, we show that the profile
variations from pulse to pulse are not reduced to a simple modulation of the
accretion rate specified by external conditions.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 11:22:04 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Tsygankov",
"S. S.",
""
],
[
"Lutovinov",
"A. A.",
""
],
[
"Churazov",
"E. M.",
""
],
[
"Sunyaev",
"R. A.",
""
]
] |
0704.2875 | Zheng-Yu Weng | Zheng-Yu Weng | Phase String Theory for Doped Antiferromagnets | 40 pages, 31 figures, a brief review appearing on March 10, 2007 | Int. J. Mod. Phys. B21, 773-827 (2007) | 10.1142/S0217979207036722 | null | cond-mat.str-el cond-mat.supr-con | null | The recent developments of the phase string theory for doped antiferromagnets
will be briefly reviewed. Such theory is built upon a singular phase string
effect induced by the motion of holes in a doped antiferromagnet, which as a
precise property of the t-J model dictates the novel competition between the
charge and spin degrees of freedom. A global phase diagram including the
antiferromagnetic, superconducting, lower and upper pseudogap, and
high-temperature "normal" phases, as well as a series of anomalous physical
properties of these phases will be presented as the self-consistent and
systematic consequences of the phase string theory.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 10:49:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Weng",
"Zheng-Yu",
""
]
] |
0704.2876 | Maria Gorelik | M. Gorelik, V. Kac | Characters of highest weight modules over affine Lie algebras are
meromorphic functions | 20 pages | null | null | null | math-ph math.MP math.RT | null | We show that the characters of all highest weight modules over an affine Lie
algebra with the highest weight away from the critical hyperplane are
meromorphic functions in the positive half of Cartan subalgebra, their
singularities being at most simple poles at zeros of real roots. We obtain some
information about these singularities.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 10:57:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gorelik",
"M.",
""
],
[
"Kac",
"V.",
""
]
] |
0704.2877 | Konstantin Pankrashkin | Jochen Bruening, Vladimir Geyler, Konstantin Pankrashkin | Explicit Green functions for spin-orbit Hamiltonians | 8 pages | J. Phys. A 40 (2007) F697-F704 | 10.1088/1751-8113/40/30/F02 | null | math-ph math.MP | null | We derive explicit expressions for Green functions and some related
characteristics of the Rashba and Dresselhaus Hamiltonians with a uniform
magnetic field.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 11:53:10 GMT"
}
] | 2007-07-12T00:00:00 | [
[
"Bruening",
"Jochen",
""
],
[
"Geyler",
"Vladimir",
""
],
[
"Pankrashkin",
"Konstantin",
""
]
] |
0704.2878 | Pulak Ranjan Giri | Pulak Ranjan Giri | Dipole binding in a cosmic string background due to quantum anomalies | Accepted for publication in Phys. Rev. A | Phys.Rev.A76:012114,2007 | 10.1103/PhysRevA.76.012114 | SINP/TNP/2007/06 | hep-th gr-qc | null | We propose quantum dynamics for the dipole moving in cosmic string background
and show that the classical scale symmetry of a particle moving in cosmic
string background is still restored even in the presence of dipole moment of
the particle. However, we show that the classical scale symmetry is broken due
to inequivalent quantization of the the non-relativistic system. The
consequence of this quantum anomaly is the formation of bound state in the
interval \xi\in(-1,1). The inequivalent quantization is characterized by a
1-parameter family of self-adjoint extension parameter \Sigma. We show that
within the interval \xi\in(-1,1), cosmic string with zero radius can bind the
dipole and the dipole does not fall into the singularity.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 12:03:09 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 14:09:37 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Giri",
"Pulak Ranjan",
""
]
] |
0704.2879 | Mikhail Vladimirovich Deryabin | Mikhail V. Deryabin | Helicity-type integral invariants for Hamiltonian systems | 7 pages | null | null | null | math.DG math.DS | null | In this note, we consider generalizations of the asymptotic Hopf invariant,
or helicity, for Hamiltonian systems with one-and-a-half degrees of freedom and
symplectic diffeomorphisms of a two-disk to itself.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 12:59:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Deryabin",
"Mikhail V.",
""
]
] |
0704.2880 | Pantelis Manousselis | P. Aschieri, H. Steinacker, J. Madore, P. Manousselis, G. Zoupanos | Fuzzy Extra Dimensions: Dimensional Reduction, Dynamical Generation and
Renormalizability | 18 pages, Based on invited talks presented at various conferences,
Minor corrections, Acknowledgements added | null | null | null | hep-th | null | We examine gauge theories defined in higher dimensions where theextra
dimensions form a fuzzy (finite matrix) manifold. First we reinterpret these
gauge theories as four-dimensional theories with Kaluza-Klein modes and then we
perform a generalized \`a la Forgacs-Manton dimensional reduction. We emphasize
some striking features emerging in the later case such as (i) the appearance of
non-abelian gauge theories in four dimensions starting from an abelian gauge
theory in higher dimensions, (ii) the fact that the spontaneous symmetry
breaking of the theory takes place entirely in the extra dimensions and (iii)
the renormalizability of the theory both in higher as well as in four
dimensions. Then reversing the above approach we present a renormalizable four
dimensional SU(N) gauge theory with a suitable multiplet of scalar fields,
which via spontaneous symmetry breaking dynamically develops extra dimensions
in the form of a fuzzy sphere. We explicitly find the tower of massive
Kaluza-Klein modes consistent with an interpretation as gauge theory on $M^4
\times S^2$, the scalars being interpreted as gauge fields on $S^2$. Depending
on the parameters of the model the low-energy gauge group can be of the form
$SU(n_1) \times SU(n_2) \times U(1)$.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 13:23:37 GMT"
},
{
"version": "v2",
"created": "Sun, 29 Apr 2007 11:23:28 GMT"
},
{
"version": "v3",
"created": "Sun, 6 May 2007 11:16:39 GMT"
},
{
"version": "v4",
"created": "Tue, 9 Oct 2007 06:37:59 GMT"
}
] | 2007-10-09T00:00:00 | [
[
"Aschieri",
"P.",
""
],
[
"Steinacker",
"H.",
""
],
[
"Madore",
"J.",
""
],
[
"Manousselis",
"P.",
""
],
[
"Zoupanos",
"G.",
""
]
] |
0704.2881 | Daisuke Tatsumi | Daisuke Tatsumi, Ryutaro Takahashi, Koji Arai, Noriyasu Nakagawa,
Kazuhiro Agatsuma, Toshitaka Yamazaki, Mitsuhiro Fukushima, Masa-Katsu
Fujimoto, Akiteru Takamori, Alessandro Bertolini, Virginio Sannibale,
Riccardo DeSalvo, Szabolcs Marka, Masaki Ando, Kimio Tsubono, Tomomi Akutsu,
Kazuhiro Yamamoto, Hideki Ishitsuka, Takashi Uchiyama, Shinji Miyoki,
Masatake Ohashi, Kazuaki Kuroda, Norichika Awaya, Nobuyuki Kanda, Akito
Araya, Souichi Telada, Takayuki Tomaru, Tomiyoshi Haruyama, Akira Yamamoto,
Nobuaki Sato, Toshitaka Suzuki and Takakazu Shintomi | Current status of Japanese detectors | 6 pages, 5 figures, Proceedings of GWDAW-11 | Class.Quant.Grav.24:S399-S404,2007 | 10.1088/0264-9381/24/19/S03 | null | gr-qc | null | Current status of TAMA and CLIO detectors in Japan is reported in this
article. These two interferometric gravitational-wave detectors are being
developed for the large cryogenic gravitational wave telescope (LCGT) which is
a future plan for detecting gravitational wave signals at least once per year.
TAMA300 is being upgraded to improve the sensitivity in low frequency region
after the last observation experiment in 2004. To reduce the seismic noises, we
are installing new seismic isolation system, which is called TAMA Seismic
Attenuation System, for the four test masses. We confirmed stable mass locks of
a cavity and improvements of length and angular fluctuations by using two SASs.
We are currently optimizing the performance of the third and fourth SASs. We
continue TAMA300 operation and R&D studies for LCGT. Next data taking in the
summer of 2007 is planned.
CLIO is a 100-m baseline length prototype detector for LCGT to investigate
interferometer performance in cryogenic condition. The key features of CLIO are
that it locates Kamioka underground site for low seismic noise level, and
adopts cryogenic Sapphire mirrors for low thermal noise level. The first
operation of the cryogenic interferometer was successfully demonstrated in
February of 2006. Current sensitivity at room temperature is close to the
target sensitivity within a factor of 4. Several observation experiments at
room temperature have been done. Once the displacement noise reaches at thermal
noise level of room temperature, its improvement by cooling test mass mirrors
should be demonstrated.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 13:25:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Tatsumi",
"Daisuke",
""
],
[
"Takahashi",
"Ryutaro",
""
],
[
"Arai",
"Koji",
""
],
[
"Nakagawa",
"Noriyasu",
""
],
[
"Agatsuma",
"Kazuhiro",
""
],
[
"Yamazaki",
"Toshitaka",
""
],
[
"Fukushima",
"Mitsuhiro",
""
],
[
"Fujimoto",
"Masa-Katsu",
""
],
[
"Takamori",
"Akiteru",
""
],
[
"Bertolini",
"Alessandro",
""
],
[
"Sannibale",
"Virginio",
""
],
[
"DeSalvo",
"Riccardo",
""
],
[
"Marka",
"Szabolcs",
""
],
[
"Ando",
"Masaki",
""
],
[
"Tsubono",
"Kimio",
""
],
[
"Akutsu",
"Tomomi",
""
],
[
"Yamamoto",
"Kazuhiro",
""
],
[
"Ishitsuka",
"Hideki",
""
],
[
"Uchiyama",
"Takashi",
""
],
[
"Miyoki",
"Shinji",
""
],
[
"Ohashi",
"Masatake",
""
],
[
"Kuroda",
"Kazuaki",
""
],
[
"Awaya",
"Norichika",
""
],
[
"Kanda",
"Nobuyuki",
""
],
[
"Araya",
"Akito",
""
],
[
"Telada",
"Souichi",
""
],
[
"Tomaru",
"Takayuki",
""
],
[
"Haruyama",
"Tomiyoshi",
""
],
[
"Yamamoto",
"Akira",
""
],
[
"Sato",
"Nobuaki",
""
],
[
"Suzuki",
"Toshitaka",
""
],
[
"Shintomi",
"Takakazu",
""
]
] |
0704.2882 | Xinyu Dai | Xinyu Dai, Francesco Shankar, and Gregory R. Sivakoff (Ohio State
Univ.) | 2MASS Reveals a Large Intrinsic Fraction of BALQSOs | 20 pages, 6 figures, accepted by ApJ | Astrophys.J.672.108-114,2008 | 10.1086/523688 | null | astro-ph | null | The intrinsic fraction of broad absorption line quasars (BALQSOs) is
important in constraining geometric and evolutionary models of quasars. We
present the fraction of BALQSOs in 2MASS detected quasars within the SDSS DR3
sample in the redshift range of 1.7 < z < 4.38. The fraction of BALQSOs is
40.4^{+3.4}_{-3.3}% in the 2MASS 99% database K_s band completeness sample, and
38.5^{+1.7}_{-1.7}% in the larger 2MASS sample extending below the completeness
limit. These fractions are significantly higher than the 26% reported in the
optical bands for the same parent sample. We also present the fraction of
BALQSOs as functions of apparent magnitudes, absolute magnitudes, and redshift
in the 2MASS and SDSS bands. The 2MASS fractions are consistently higher than
the SDSS fractions in every comparison, and the BALQSO fractions steadily
increase with wavelength from the SDSS u to the 2MASS K_s bands. Furthermore,
the i - K_s color distributions of BALQSOs and non-BALQSOs indicate that
BALQSOs are redder than non-BALQSOs, with a K-S test probability of 2e-12.
These results are consistent with the spectral difference between BALQSOs and
non-BALQSOs including both the absorption troughs and dust extinction in
BALQSOs, which leads to significant selection biases against BALQSOs in the
optical bands. Using a simple simulation incorporating the luminosity function
of quasars and the amount of obscuration for BALQSOs, we simultaneously fit the
BALQSO fractions in the SDSS and 2MASS bands. We obtain a true BALQSO fraction
of 43\pm2% for luminous quasars (M_{K_s} \lesssim -30.1 mag).
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 13:31:20 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Sep 2007 15:42:32 GMT"
}
] | 2012-10-18T00:00:00 | [
[
"Dai",
"Xinyu",
"",
"Ohio State\n Univ."
],
[
"Shankar",
"Francesco",
"",
"Ohio State\n Univ."
],
[
"Sivakoff",
"Gregory R.",
"",
"Ohio State\n Univ."
]
] |
0704.2883 | Roehner | Charles Jego, Bertrand M. Roehner | A physicist's view of the notion of "racism" | 14 pages, 3 figures, 1 table | null | null | null | physics.soc-ph | null | It is not uncommon, e.g. in the media, that specific groups are categorized
as being racist. Based on an extensive dataset of intermarriage statistics our
study questions the legitimacy of such characterizations. It suggests that, far
from being group-dependent, segregation mechanisms are instead
situation-dependent. More precisely, the degree of integration of a minority in
terms of the frequency of intermarriage is seen to crucially depend upon the
the proportion p of the minority. Thus, a population may have a segregative
behavior with respect to a high-p (p>20%) minority A and at the same time a
tolerant attitude toward a low-p (p<2%) minority B. This remains true even when
A and B represent the same minority; for instance Black-White intermarriage is
much more frequent in Montana than it is in South Carolina. In short, the
nature of minority groups is largely irrelevant, the key factor being their
proportion in a given area.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 13:42:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Jego",
"Charles",
""
],
[
"Roehner",
"Bertrand M.",
""
]
] |
0704.2884 | Shamil Shakirov | V.Dolotin, A.Morozov and Sh.Shakirov | Higher Nilpotent Analogues of A-infinity Structure | preliminary version, essential corrections made | Phys.Lett.B651:71-73,2007 | 10.1016/j.physletb.2007.05.022 | ITEP/TH-14/07 | hep-th math.GT | null | Higher nilpotent analogues of the $A-\infty$-structure are explicitly defined
on arbitrary simplicial complexes, generalizing explicit construction of
/hep-th/0704.2609. These structures are associated with the higher nilpotent
differential $d_n$, satisfying $d_n^n =0$, which is naturally defined on
triangulated manifolds (tetrahedral lattices). The deformation $D_n = (I +
\epsilon_n) d_n (I + \epsilon_n)^{-1}$ is defined with the help of the
$n$-versions of discrete exterior product $\wedge_n$ and the $K_n$-operator.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 14:14:31 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Apr 2007 23:10:41 GMT"
},
{
"version": "v3",
"created": "Wed, 10 Oct 2007 11:29:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dolotin",
"V.",
""
],
[
"Morozov",
"A.",
""
],
[
"Shakirov",
"Sh.",
""
]
] |
0704.2885 | Pascal Moyal | Pascal Moyal | Convex comparison of service disciplines in real time queues | null | null | null | null | math.PR | null | We present a comparison of the service disciplines in real-time queueing
systems (the customers have a deadline before which they should enter the
service booth). We state that giving priority to customers having an early
deadline minimizes the average stationary lateness. We show this result by
comparing adequate random vectors with the Schur-Convex majorization ordering.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 14:39:09 GMT"
},
{
"version": "v2",
"created": "Tue, 8 Jan 2008 13:36:59 GMT"
}
] | 2008-01-08T00:00:00 | [
[
"Moyal",
"Pascal",
""
]
] |
0704.2886 | Mikhail Vladimirovich Deryabin | Mikhail V. Deryabin | Control of mechanical systems on Lie groups and ideal hydrodynamics | 25 pages | null | null | null | math.OC math.DS | null | In contrast to the Euler-Poincar{\'e} reduction of geodesic flows of left- or
right-invariant metrics on Lie groups to the corresponding Lie algebra (or its
dual), one can consider the reduction of the geodesic flows to the group
itself. The reduced vector field has a remarkable hydrodynamic interpretation:
it is a velocity field for a stationary flow of an ideal fluid. Right- or
left-invariant symmetry fields of the reduced field define vortex manifolds for
such flows.
Consider now a mechanical system, whose configuration space is a Lie group
and whose Lagrangian is invariant to left translations on that group, and
assume that the mass geometry of the system may change under the action of
internal control forces. Such system can also be reduced to the Lie group. With
no controls, this mechanical system describes a geodesic flow of the
left-invariant metric, given by the Lagrangian, and thus its reduced flow is a
stationary ideal fluid flow on the Lie group. The standard control problem for
such system is to find the conditions, under which the system can be brought
from any initial position in the configuration space to another preassigned
position by changing its mass geometry. We show that under these conditions, by
changing the mass geometry, one can also bring one vortex manifold to any other
preassigned vortex manifold.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 14:58:11 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Deryabin",
"Mikhail V.",
""
]
] |
0704.2887 | Lola Balaguer-Nu\~nez | L. Balaguer-N\'u\~nez (1,2,3), D. Galad\'i-Enr\'iquez (4), C. Jordi
(1,5) ((1)UB Spain, (2)SHAO China,(3) IoA Cambridge UK,(4) IAA Spain,(5) IEEC
Spain) | $uvby-H_\beta$ CCD photometry and membership segregation of the open
cluster NGC2682 (M67) | 16 pages, 14 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20067003 | null | astro-ph | null | Following deep astrometric and photometric study of the cluster NGC2682
(M67), we are able to accurately determine its fundamental parameters. Being an
old and rich cluster, M67 is a relevant object for the analysis of the Galactic
disk evolution. M67 is well studied but the lack of a wide and deep Stromgren
photometric study makes our results worthwhile. The brightest stars of the open
cluster M67 were used as uvby-Hbeta standard stars in our studies of NGC1817
and NGC2548, and the extension of the field covered, as well as the amount of
observations, allowed to obtain the best set of Stromgren data ever published
for this cluster. We discuss the results of our CCD uvby-Hbeta
intermediate-band photometry, covering an area of about 50'x50' down to V 19.
Moreover, a complete membership segregation based on astrometric and
photometric criteria is obtained. The photometric analysis of a selected sample
of stars yields a reddening value of E(b-y)= 0.03\pm0.03, a distance modulus of
V_0-M_V= 9.7\pm0.2 and [Fe/H]= 0.01\pm0.14. Through isochrone fitting we found
an age of log t= 9.6\pm0.1 (4.2\pm0.2 Gyr). A clump of approximately 60 stars
around V= 16, (b-y)= 0.4 could be interpreted as a population of
pre-cataclysmic variable stars (if members), or as a stream of field G-type
stars placed at twice the distance of the cluster (if non-members).
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 15:00:24 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Balaguer-Núñez",
"L.",
""
],
[
"Galadí-Enríquez",
"D.",
""
],
[
"Jordi",
"C.",
""
]
] |
0704.2888 | Charles Dermer | Charles D. Dermer (NRL) | The Extragalactic Gamma Ray Background | 5 pages, 1 figures, in Proc. of the 1st GLAST Symposium, Feb 5-8,
2007, Stanford, AIP, Eds. S. Ritz, P. F. Michelson, and C. Meegan; references
added, minor changes | AIP Conf.Proc.921:122-126,2007 | 10.1063/1.2757282 | null | astro-ph | null | One way to understand the nonthermal history of the universe is by
establishing the origins of the unresolved and truly diffuse extragalactic
gamma rays. Dim blazars and radio/gamma galaxies certainly make an important
contribution to the galactic gamma-ray background given the EGRET discoveries,
and previous treatments are reviewed and compared with a new analysis. Studies
of the gamma-ray intensity from cosmic rays in star-forming galaxies and from
structure formation shocks, as well as from dim GRBs, are briefly reviewed. A
new hard gamma-ray source class seems required from the predicted aggregate
intensity compared with the measured intensity.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 15:05:26 GMT"
},
{
"version": "v2",
"created": "Thu, 10 May 2007 19:35:47 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Dermer",
"Charles D.",
"",
"NRL"
]
] |
0704.2889 | Marc Mars | Lars Andersson, Marc Mars, Walter Simon | Stability of marginally outer trapped surfaces and existence of
marginally outer trapped tubes | 33 pages, no figures, typos corrected, minor changes in presentation | null | null | null | gr-qc | null | The present work extends our short communication Phys. Rev. Lett. 95, 111102
(2005). For smooth marginally outer trapped surfaces (MOTS) in a smooth
spacetime we define stability with respect to variations along arbitrary
vectors v normal to the MOTS. After giving some introductory material about
linear non self-adjoint elliptic operators, we introduce the stability operator
L_v and we characterize stable MOTS in terms of sign conditions on the
principal eigenvalue of L_v. The main result shows that given a strictly stable
MOTS S contained in one leaf of a given reference foliation in a spacetime,
there is an open marginally outer trapped tube (MOTT), adapted to the reference
foliation, which contains S. We give conditions under which the MOTT can be
completed. Finally, we show that under standard energy conditions on the
spacetime, the MOTT must be either locally achronal, spacelike or null.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 15:13:38 GMT"
},
{
"version": "v2",
"created": "Tue, 22 May 2007 15:13:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Andersson",
"Lars",
""
],
[
"Mars",
"Marc",
""
],
[
"Simon",
"Walter",
""
]
] |
0704.2890 | Yan Soibelman | Yan Soibelman | Quantum p-adic spaces and quantum p-adic groups | Few mistprints corrected. To appear in Alexander Reznikov Memorial
Volume | null | null | null | math.QA hep-th math.AG math.RA math.RT | null | We discuss examples of non-commutative spaces over non-archimedean fields.
Those include non-commutative and quantum affinoid algebras, quantized K3
surfaces and quantized locally analytic p-adic groups.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 15:25:26 GMT"
},
{
"version": "v2",
"created": "Sun, 26 Aug 2007 09:36:22 GMT"
}
] | 2007-08-26T00:00:00 | [
[
"Soibelman",
"Yan",
""
]
] |
0704.2891 | Dmitry Gourevitch | Avraham Aizenbud and Dmitry Gourevitch | Schwartz functions on Nash manifolds | 35 pages, LaTex. v3:minor changes + reference to results of duCloux | International Mathematics Research Notices, Vol. 2008, 2008:
rnm155-37 | 10.1093/imrn/rnm155 | null | math.AG math.RT | null | In this paper we extend the notions of Schwartz functions, tempered functions
and generalized Schwartz functions to Nash (i.e. smooth semi-algebraic)
manifolds. We reprove for this case classically known properties of Schwartz
functions on $R^n$ and build some additional tools which are important in
representation theory.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 15:46:15 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Apr 2007 11:31:13 GMT"
},
{
"version": "v3",
"created": "Wed, 5 Dec 2007 13:45:09 GMT"
}
] | 2008-01-20T00:00:00 | [
[
"Aizenbud",
"Avraham",
""
],
[
"Gourevitch",
"Dmitry",
""
]
] |
0704.2892 | Gianluca Colo` | Sara Fracasso and Gianluca Colo' | Spin-isospin nuclear response using the existing microscopic Skyrme
functionals | Submitted to Phys. Rev. C | Phys.Rev.C76:044307,2007 | 10.1103/PhysRevC.76.044307 | null | nucl-th | null | Our paper aims at providing an answer to the question whether one can
reliably describe the properties of the most important spin-isospin nuclear
excitations, by using the available non-relativistic Skyrme energy functionals.
Our method, which has been introduced in a previous publication devoted to the
Isobaric Analog states, is the self-consistent Quasiparticle Random Phase
Approximation (QRPA). The inclusion of pairing is instrumental for describing a
number of experimentally measured spherical systems which are characterized by
open shells. We discuss the effect of isoscalar and isovector pairing
correlations. Based on the results for the Gamow-Teller resonance in $^{90}$Zr,
in $^{208}$Pb and in few Sn isotopes, we draw definite conclusions on the
performance of different Skyrme parametrizations, and we suggest improvements
for future fits. We also use the spin-dipole resonance as a benchmark of our
statements.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 16:36:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Fracasso",
"Sara",
""
],
[
"Colo'",
"Gianluca",
""
]
] |
0704.2893 | Dimitri M. Gangardt | D.M. Gangardt, S.K. Nechaev | Wetting transition on a one-dimensional disorder | 16 pages, 5 figures | null | 10.1007/s10955-007-9433-7 | null | cond-mat.stat-mech cond-mat.dis-nn | null | We consider wetting of a one-dimensional random walk on a half-line $x\ge 0$
in a short-ranged potential located at the origin $x=0$. We demonstrate
explicitly how the presence of a quenched chemical disorder affects the
pinning-depinning transition point. For small disorders we develop a
perturbative technique which enables us to compute explicitly the averaged
temperature (energy) of the pinning transition. For strong disorder we compute
the transition point both numerically and using the renormalization group
approach. Our consideration is based on the following idea: the random
potential can be viewed as a periodic potential with the period $n$ in the
limit $n\to\infty$. The advantage of our approach stems from the ability to
integrate exactly over all spatial degrees of freedoms in the model and to
reduce the initial problem to the analysis of eigenvalues and eigenfunctions of
some special non-Hermitian random matrix with disorder--dependent diagonal and
constant off-diagonal coefficients. We show that even for strong disorder the
shift of the averaged pinning point of the random walk in the ensemble of
random realizations of substrate disorder is indistinguishable from the pinning
point of the system with preaveraged (i.e. annealed) Boltzmann weight.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 16:59:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gangardt",
"D. M.",
""
],
[
"Nechaev",
"S. K.",
""
]
] |
0704.2894 | Brant M. Johnson | PHENIX Collaboration, S.S. Adler, et al | Measurement of density correlations in pseudorapidity via charged
particle multiplicity fluctuations in Au+Au collisions at sqrt(s_NN)=200 GeV | 331 authors, 32 pages text, RevTeX4, 7 figures, 27 tables. Submitted
to Physical Review C. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be) publicly
available at http://www.phenix.bnl.gov/papers.html | Phys.Rev.C76:034903,2007 | 10.1103/PhysRevC.76.034903 | null | nucl-ex | null | Longitudinal density correlations of produced matter in Au+Au collisions at
sqrt(s_NN)=200 GeV have been measured from the inclusive charged particle
distributions as a function of pseudorapidity window sizes. The extracted
\alpha \xi parameter, related to the susceptibility of the density fluctuations
in the long wavelength limit, exhibits a non-monotonic behavior as a function
of the number of participant nucleons, N_part. A local maximum is seen at
N_part ~ 90, with corresponding energy density based on the Bjorken picture of
\epsilon_Bj \tau ~ 2.4 GeV/(fm^2 c) with a transverse area size of 60 fm^2.
This behavior may suggest a critical phase boundary based on the
Ginzburg-Landau framework.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 17:23:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"PHENIX Collaboration",
"",
""
],
[
"Adler",
"S. S.",
""
]
] |
0704.2895 | Herbert Hamber | Herbert W. Hamber | Discrete and Continuum Quantum Gravity | 222 pages, 42 figures | null | null | null | hep-th gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I review discrete and continuum approaches to quantized gravity based on the
covariant Feynman path integral approach.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 17:34:49 GMT"
},
{
"version": "v2",
"created": "Thu, 25 Oct 2007 23:17:57 GMT"
},
{
"version": "v3",
"created": "Mon, 19 Jan 2009 20:32:07 GMT"
}
] | 2009-01-19T00:00:00 | [
[
"Hamber",
"Herbert W.",
""
]
] |
0704.2896 | Adrian Melott | Bruce S.Lieberman and Adrian L. Melott (University of Kansas) | Considering the Case for Biodiversity Cycles: Reexamining the Evidence
for Periodicity in the Fossil Record | Minor modifications to reflect final published version | PLoS ONE 2(8): e759 (2007) | 10.1371/journal.pone.0000759 | null | q-bio.PE astro-ph physics.geo-ph | null | Medvedev and Melott (2007) have suggested that periodicity in fossil
biodiversity may be induced by cosmic rays which vary as the Solar System
oscillates normal to the galactic disk. We re-examine the evidence for a 62
million year (Myr) periodicity in biodiversity throughout the Phanerozoic
history of animal life reported by Rohde & Mueller (2005), as well as related
questions of periodicity in origination and extinction. We find that the signal
is robust against variations in methods of analysis, and is based on
fluctuations in the Paleozoic and a substantial part of the Mesozoic.
Examination of origination and extinction is somewhat ambiguous, with results
depending upon procedure. Origination and extinction intensity as defined by RM
may be affected by an artifact at 27 Myr in the duration of stratigraphic
intervals. Nevertheless, when a procedure free of this artifact is implemented,
the 27 Myr periodicity appears in origination, suggesting that the artifact may
ultimately be based on a signal in the data. A 62 Myr feature appears in
extinction, when this same procedure is used. We conclude that evidence for a
periodicity at 62 Myr is robust, and evidence for periodicity at approximately
27 Myr is also present, albeit more ambiguous.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 12:08:35 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 18:25:49 GMT"
},
{
"version": "v3",
"created": "Wed, 22 Aug 2007 15:03:22 GMT"
}
] | 2007-08-22T00:00:00 | [
[
"Lieberman",
"Bruce S.",
"",
"University of Kansas"
],
[
"Melott",
"Adrian L.",
"",
"University of Kansas"
]
] |
0704.2897 | Mark Sapir | A.Yu. Ol'shanskii, M.V. Sapir | A 2-generated 2-related group with no non-trivial finite factors | 3 pages | null | null | null | math.GR math.GT | null | We construct a 2-generated 2-related group without non-trivial finite
factors. That answers a question of J. Button.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 18:04:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ol'shanskii",
"A. Yu.",
""
],
[
"Sapir",
"M. V.",
""
]
] |
0704.2898 | Cojocaru | S. Cojocaru | Green's function of a finite chain and the discrete Fourier transform | preprint of the paper published in Int. J. Modern Physics B Vol. 20,
No. 5 (2006) 593-605 | International Journal of Modern Physics B Vol. 20, No. 5 (2006)
593-605 | 10.1142/S0217979206033401 | null | math-ph math.MP | null | A new expression for the Green's function of a finite one-dimensional lattice
with nearest neighbor interaction is derived via discrete Fourier transform.
Solution of the Heisenberg spin chain with periodic and open boundary
conditions is considered as an example. Comparison to Bethe ansatz clarifies
the relation between the two approaches.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 18:09:06 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Cojocaru",
"S.",
""
]
] |
0704.2899 | Mark Sapir | M. V. Sapir | Some group theory problems | 25 pages | null | null | null | math.GR math.GT | null | This is a survey of some problems in geometric group theory which I find
interesting. The problems are from different areas of group theory. Each
section is devoted to problems in one area. It contains an introduction where I
give some necessary definitions and motivations, problems and some discussions
of them. For each problem, I try to mention the author. If the author is not
given, the problem, to the best of my knowledge, was formulated by me first.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 18:15:20 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sapir",
"M. V.",
""
]
] |
0704.2900 | Marco Maggesi | Andre' Hirschowitz and Marco Maggesi | Higher-order theories | 12 pages | null | null | null | cs.LO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extend our approach to abstract syntax (with binding constructions)
through modules and linearity. First we give a new general definition of arity,
yielding the companion notion of signature. Then we obtain a modularity result
as requested by Ghani and Uustalu (2003): in our setting, merging two
extensions of syntax corresponds to building an amalgamated sum. Finally we
define a natural notion of equation concerning a signature and prove the
existence of an initial semantics for a so-called representable signature
equipped with a set of equations.
| [
{
"version": "v1",
"created": "Sun, 22 Apr 2007 18:19:46 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Sep 2008 15:45:27 GMT"
}
] | 2008-09-09T00:00:00 | [
[
"Hirschowitz",
"Andre'",
""
],
[
"Maggesi",
"Marco",
""
]
] |
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