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0708.2549
Christian Enz
Christian Enz
The scalar curvature flow in Lorentzian manifolds
Chapter 1 was replaced by reference due to text overlap. arXiv admin note: substantial text overlap with arXiv:math/0207054 by other authors
null
null
null
math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We prove the existence of closed hypersurfaces of prescribed scalar curvature in globally hyperbolic Lorentzian manifolds provided there are barriers.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 14:57:29 GMT" }, { "version": "v2", "created": "Thu, 25 Feb 2016 02:33:17 GMT" } ]
2016-02-26T00:00:00
[ [ "Enz", "Christian", "" ] ]
0708.2550
Simon Kimber Mr
S. A. J. Kimber, M. A. de Vries, J. Sanchez-Benitez, K. V. Kamenev, J. P. Attfield
Triplet Dimerization Crossover Driven by Magnetic Frustration in In2VO5
submitted for publication
null
10.1103/PhysRevB.77.014428
null
cond-mat.str-el
null
In2VO5, containing magnetically frustrated zig-zag chains, shows a remarkable magnetic crossover at 120 K between paramagnetic states with positive (17 K) and negative (-70 K) Weiss temperatures. Magnetic moment and entropy data show that the V4+ S = 1/2 spins condense into S = 1 triplet dimers below the crossover. A further freezing of the antiferromagnetically coupled triplet dimers into a global singlet state is observed at 2.5 K, with no long range magnetic order down to 0.42 K and in fields up to 9 T. No structural V-V dimerization is observed by high-resolution X-ray diffraction down to 10 K, but a subtle lattice anomaly evidences a spin-lattice coupling in the triplet dimer state. This is assigned to longitudinal oxygen displacement modes that reduce frustration within the chains and so couple to the spin dimer fluctuations.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 15:25:54 GMT" } ]
2009-11-13T00:00:00
[ [ "Kimber", "S. A. J.", "" ], [ "de Vries", "M. A.", "" ], [ "Sanchez-Benitez", "J.", "" ], [ "Kamenev", "K. V.", "" ], [ "Attfield", "J. P.", "" ] ]
0708.2551
Jeremy Dunning-Davies
A. D. Law and J. Dunning-Davies
Comments on Possible Variation of the Universal Constants
7 pages
null
null
null
physics.gen-ph
null
Discussion of the constancy, or otherwise, of the various so-called universal constants which abound in physics has continued for many years. However, relatively recent observations, which appear to indicate a variation in the value of the fine structure constant, have reignited the subject. These observations relate to quasars and that in itself raises questions. Also, since many of the arguments utilise the Bekenstein-Hawking expression for the entropy of a black hole, further controversy is introduced into the discussion immediately. In what follows these two points will be examined and some less well-known theoretical considerations introduced which, hopefully, will instigate wider examination of this topic.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 16:04:29 GMT" } ]
2007-08-21T00:00:00
[ [ "Law", "A. D.", "" ], [ "Dunning-Davies", "J.", "" ] ]
0708.2552
\"Ozlem Ye\c{s}ilta\c{s}
Ozlem Yesiltas, Bengu Demircioglu
Quantum Hamilton-Jacobi Approach to Two Dimensional Singular Oscillator
8 pages
null
null
null
quant-ph
null
We have obtained the solutions of two dimensional singular oscillator which is known as the quantum Calogero-Sutherland model both in cartesian and parabolic coordinates within the framework of quantum Hamilton Jacobi formalism. Solvability conditions and eigenfunctions are obtained by using the singularity structures of quantum momentum functions under some conditions. New potentials are generated by using the first two states of singular oscillator for parabolic coordinates.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:05:04 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 18:26:52 GMT" }, { "version": "v3", "created": "Sun, 27 Apr 2008 16:54:53 GMT" } ]
2008-04-27T00:00:00
[ [ "Yesiltas", "Ozlem", "" ], [ "Demircioglu", "Bengu", "" ] ]
0708.2553
Zijian Yao
Zi-Jian Yao, Jian-Xin Li, Z. D. Wang
Band structure renormalization and weak pseudogap behavior in Na_{0.33}CoO_2: Fluctuation exchange study based on a single band model
5 pages, 5 figures
Phys. Rev. B 76, 212506 (2007)
10.1103/PhysRevB.76.212506
null
cond-mat.str-el
null
Based on a single band Hubbard model and the fluctuation exchange approximation, the effective mass and the energy band renormalization in Na$_{0.33}$CoO$_2$ is elaborated. The renormalization is observed to exhibit certain kind of anisotropy, which agrees qualitatively with the angle-resolved photoemission spectroscopy (ARPES) measurements. Moreover, the spectral function and density of states (DOS) in the normal state are calculated, with a weak pseudogap behavior being seen, which is explained as a result of the strong Coulomb correlations. Our results suggest that the large Fermi surface (FS) associated with the $a_{1g}$ band plays likely a central role in the charge dynamics.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 16:50:06 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 08:34:55 GMT" }, { "version": "v3", "created": "Fri, 24 Aug 2007 11:53:10 GMT" }, { "version": "v4", "created": "Sun, 16 Mar 2008 06:28:01 GMT" } ]
2008-03-16T00:00:00
[ [ "Yao", "Zi-Jian", "" ], [ "Li", "Jian-Xin", "" ], [ "Wang", "Z. D.", "" ] ]
0708.2554
Eyal Gruss
Eyal Gruss and Yaron Oz
On the Entropy of Four-Dimensional Near-Extremal N=2 Black Holes with R^2-Terms
20 pages. v2: appendix added. references added. minor fixes. v3: minor comments. up to date with JHEP version. v4: significant revision, fixed error in main result (shift in entropy should vanish), fixed equations of motion (not affecting other results). v5: fixed abstract and references
JHEP 0712:050,2007
10.1088/1126-6708/2007/12/050
null
hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the entropy of four-dimensional near-extremal N=2 black holes. Without R^2-terms, the Bekenstein-Hawking entropy formula has the structure of the extremal black holes entropy with a shift of the charges depending on the non-extremality parameter and the moduli at infinity. We derive a generalized Wald entropy formula for non-extremal N=2 black holes with R^2-terms. We construct a class of small near-extremal horizon solutions with R^2-terms. In this case the entropy is the same as in the extremal case to order O(mu^2), and does not exhibit the charge shift behavior.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 06:29:37 GMT" }, { "version": "v2", "created": "Tue, 18 Sep 2007 22:05:35 GMT" }, { "version": "v3", "created": "Fri, 14 Dec 2007 10:00:33 GMT" }, { "version": "v4", "created": "Sun, 8 Nov 2009 15:21:05 GMT" }, { "version": "v5", "created": "Tue, 7 Jun 2011 13:38:27 GMT" } ]
2011-06-08T00:00:00
[ [ "Gruss", "Eyal", "" ], [ "Oz", "Yaron", "" ] ]
0708.2555
Kimitake Hayasaki
Kimitake Hayasaki, Shin Mineshige and Luis C. Ho
A supermassive binary black hole with triple disks
Accepted for publication in the Astrophysical Journal, 16 pages, 11 figures. High Resolution Version is Available at http://www2.yukawa.kyoto-u.ac.jp/~kimitake/bbhs.html
null
10.1086/588837
null
astro-ph gr-qc
null
Hierarchical structure formation inevitably leads to the formation of supermassive binary black holes (BBHs) with a sub-parsec separation in galactic nuclei. However, to date there has been no unambiguous detection of such systems. In an effort to search for potential observational signatures of supermassive BBHs, we performed high-resolution smoothed particle hydrodynamics (SPH) simulations of two black holes in a binary of moderate eccentricity surrounded by a circumbinary disk. Building on our previous work, which has shown that gas can periodically transfer from the circumbinary disk to the black holes when the binary is on an eccentric orbit, the current set of simulations focuses on the formation of the individual accretion disks, their evolution and mutual interaction, and the predicted radiative signature. The variation in mass transfer with orbital phase from the circumbinary disk induces periodic variations in the light curve of the two accretion disks at ultraviolet wavelengths, but not in the optical or near-infrared. Searches for this signal offer a promising method to detect supermassive BBHs.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 20:03:02 GMT" }, { "version": "v2", "created": "Mon, 7 Apr 2008 09:12:41 GMT" } ]
2009-11-13T00:00:00
[ [ "Hayasaki", "Kimitake", "" ], [ "Mineshige", "Shin", "" ], [ "Ho", "Luis C.", "" ] ]
0708.2556
Ori Gurel-Gurevich
Ori Gurel-Gurevich
Pursuit-Evasion Games with Incomplete Information in Discrete Time
14 pages
null
null
null
math.PR
null
Pursuit-Evasion Games (in discrete time) are stochastic games with nonnegative daily payoffs, with the final payoff being the cumulative sum of payoffs during the game. We show that such games admit a value even in the presence of incomplete information and that this value is uniform, i.e. there are epsilon-optimal strategies for both players that are epsilon-optimal in any long enough prefix of the game. We give an example to demonstrate that nonnegativity is essential and expand the results to leavable games.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 18:23:55 GMT" } ]
2007-08-21T00:00:00
[ [ "Gurel-Gurevich", "Ori", "" ] ]
0708.2557
Christian Schaffner
Ivan Damgaard, Serge Fehr, Louis Salvail, Christian Schaffner
Secure Identification and QKD in the Bounded-Quantum-Storage Model
22 pages, v2: included one missing reference, v3: substantial update: using more natural version of min-entropy with according changes in min-entropy splitting and security claims
full version of CRYPTO 2007, LNCS 4622, pages 342-359
null
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of secure identification: user U proves to server S that he knows an agreed (possibly low-entropy) password w, while giving away as little information on w as possible, namely the adversary can exclude at most one possible password for each execution of the scheme. We propose a solution in the bounded-quantum-storage model, where U and S may exchange qubits, and a dishonest party is assumed to have limited quantum memory. No other restriction is posed upon the adversary. An improved version of the proposed identification scheme is also secure against a man-in-the-middle attack, but requires U and S to additionally share a high-entropy key k. However, security is still guaranteed if one party loses k to the attacker but notices the loss. In both versions of the scheme, the honest participants need no quantum memory, and noise and imperfect quantum sources can be tolerated. The schemes compose sequentially, and w and k can securely be re-used. A small modification to the identification scheme results in a quantum-key-distribution (QKD) scheme, secure in the bounded-quantum-storage model, with the same re-usability properties of the keys, and without assuming authenticated channels. This is in sharp contrast to known QKD schemes (with unbounded adversary) without authenticated channels, where authentication keys must be updated, and unsuccessful executions can cause the parties to run out of keys.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 18:44:17 GMT" }, { "version": "v2", "created": "Thu, 15 Nov 2007 15:09:51 GMT" }, { "version": "v3", "created": "Wed, 5 Aug 2009 12:57:55 GMT" } ]
2009-08-05T00:00:00
[ [ "Damgaard", "Ivan", "" ], [ "Fehr", "Serge", "" ], [ "Salvail", "Louis", "" ], [ "Schaffner", "Christian", "" ] ]
0708.2558
Raymond Burston
R. B. Burston
1+1+2 gravitational perturbations on LRS class II space-times: GEM vector harmonic amplitudes
null
null
null
null
gr-qc
null
This is the second in a series of papers which considers first-order gauge-invariant and covariant gravitational perturbations to locally rotationally symmetric (LRS) class II space-times. This paper shows how to decouple a complex combination of the gravito-electromagnetic (GEM) 2-vectors with the 2-tensors describing the shear of the 2/3-sheets. An arbitrary harmonic expansion is then used along with an eigen-vector/value analysis of the first-order GEM system, analogous to the first paper in this series. This results in four real decoupled equations governing four real combinations of the harmonic amplitudes of the GEM 2-vectors and the (2/3-sheet) shear 2-tensors. Finally, these are categorized into polar and axial perturbations.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 19:42:17 GMT" } ]
2007-08-21T00:00:00
[ [ "Burston", "R. B.", "" ] ]
0708.2559
Raymond Burston
R. B. Burston
1+1+2 gravitational perturbations on LRS class II space-times: GEM scalar harmonic amplitudes
null
null
null
null
gr-qc
null
This is the third in a series of papers which considers first-order gauge-invariant and covariant gravitational perturbations to locally rotationally symmetric (LRS) class II space-times. In this paper we complete our analysis of the first-order gravito-electromagnetic (GEM) system by showing how to derive three decoupled equations governing the GEM scalar fields. One of these is for the gravito-magnetic scalar, whereas another two arise from the 2-gradient of the gravito-electric scalar.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 19:37:00 GMT" } ]
2007-08-21T00:00:00
[ [ "Burston", "R. B.", "" ] ]
0708.2560
Mark Hillery
Marianna Bonanome, Mark Hillery and Vladimir Buzek
Application of quantum algorithms to the study of permutations and group automorphisms
7 pages, 1 figure
Physical Review A 76, 012324 (2007)
10.1103/PhysRevA.76.012324
null
quant-ph
null
We discuss three applications of efficient quantum algorithms to determining properties of permutations and group automorphisms. The first uses the Bernstein-Vazirani algorithm to determine an unknown homomorphism from $Z_{p-1}^{m}$ to $Aut(Z_{p})$ where $p$ is prime. The remaining two make use of modifications of the Grover search algorithm. The first finds the fixed point of a permutation or an automorphism (assuming it has only one besides the identity). It can be generalized to find cycles of a specified size for permutations or orbits of a specified size for automorphisms. The second finds which of a set of permutations or automorphisms maps one particular element of a set or group onto another. This has relevance to the conjugacy problem for groups. We show how two of these algorithms can be implemented via programmable quantum processors. This approach opens new perspectives in quantum information processing, wherein both the data and the programs are represented by states of quantum registers. In particular, quantum programs that specify control over data can be treated using methods of quantum information theory.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 20:19:17 GMT" } ]
2009-11-13T00:00:00
[ [ "Bonanome", "Marianna", "" ], [ "Hillery", "Mark", "" ], [ "Buzek", "Vladimir", "" ] ]
0708.2561
Wei-Zhou Jiang
Wei-Zhou Jiang, Bao-An Li, Lie-Wen Chen
Mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter within the relativistic impulse approximation
13 pages, 6 figures
Phys.Rev.C76:044604,2007
10.1103/PhysRevC.76.044604
null
nucl-th nucl-ex
null
The mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter are investigated using the nucleon optical potential obtained within the relativistic impulse approximation with the empirical nucleon-nucleon scattering amplitudes and the nuclear densities obtained in the relativistic mean field model. It is found that the isospin-splitting of nucleon mean free paths, sensitive to the imaginary part of the symmetry potential, changes its sign at certain high kinetic energy. The in-medium nucleon-nucleon cross sections are analytically and numerically demonstrated to be essentially independent of the isospin asymmetry of the medium and increase linearly with density in the high energy region where the relativistic impulse approximation is applicable.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 20:35:27 GMT" } ]
2008-11-26T00:00:00
[ [ "Jiang", "Wei-Zhou", "" ], [ "Li", "Bao-An", "" ], [ "Chen", "Lie-Wen", "" ] ]
0708.2562
Todd Kemp
Todd Kemp
R-diagonal dilation semigroups
22 pages, 6 figures
null
null
null
math.FA math.OA
null
This paper addresses extensions of the complex Ornstein-Uhlenbeck semigroup to operator algebras in free probability theory. If $a_1,...,a_k$ are $\ast$-free $\mathscr{R}$-diagonal operators in a $\mathrm{II}_1$ factor, then $D_t(a_{i_1}... a_{i_n}) = e^{-nt} a_{i_1}... a_{i_n}$ defines a dilation semigroup on the non-self-adjoint operator algebra generated by $a_1,...,a_k$. We show that $D_t$ extends (in two different ways) to a semigroup of completely positive maps on the von Neumann algebra generated by $a_1,...,a_k$. Moreover, we show that $D_t$ satisfies an optimal ultracontractive property: $\|D_t\colon L^2\to L^\infty\| \sim t^{-1}$ for small $t>0$.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 21:05:37 GMT" }, { "version": "v2", "created": "Mon, 11 Feb 2008 21:20:39 GMT" } ]
2008-02-12T00:00:00
[ [ "Kemp", "Todd", "" ] ]
0708.2563
Hideo Hasegawa
Hideo Hasegawa (Tokyo Gakugei Univ.)
Dynamics of the Langevin model subjected to colored noise: Functional-integral method
26 pages, 8 figures: accepted in Physica A with minor modifications
Physica A 387 (2008) 2697.
10.1016/j.physa.2008.01.072
null
cond-mat.stat-mech cond-mat.dis-nn
null
We have discussed the dynamics of Langevin model subjected to colored noise, by using the functional-integral method (FIM) combined with equations of motion for mean and variance of the state variable. Two sets of colored noise have been investigated: (a) one additive and one multiplicative colored noise, and (b) one additive and two multiplicative colored noise. The case (b) is examined with the relevance to a recent controversy on the stationary subthreshold voltage distribution of an integrate-and-fire model including stochastic excitatory and inhibitory synapses and a noisy input. We have studied the stationary probability distribution and dynamical responses to time-dependent (pulse and sinusoidal) inputs of the linear Langevin model. Model calculations have shown that results of the FIM are in good agreement with those of direct simulations (DSs). A comparison is made among various approximate analytic solutions such as the universal colored noise approximation (UCNA). It has been pointed out that dynamical responses to pulse and sinusoidal inputs calculated by the UCNA are rather different from those of DS and the FIM, although they yield the same stationary distribution.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 21:31:26 GMT" }, { "version": "v2", "created": "Thu, 23 Aug 2007 22:43:06 GMT" }, { "version": "v3", "created": "Tue, 8 Jan 2008 18:42:48 GMT" } ]
2009-11-13T00:00:00
[ [ "Hasegawa", "Hideo", "", "Tokyo Gakugei Univ." ] ]
0708.2564
Jordan Bell
Leonhard Euler
On the sum of the series formed from the prime numbers where the prime numbers of the form $4n-1$ have a positive sign and those of the form $4n+1$ a negative sign
17 pages. E596
null
null
null
math.HO math.NT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is an English translation of the Latin original "De summa seriei ex numeris primis formatae ${1/3}-{1/5}+{1/7}+{1/11}-{1/13}-{1/17}+{1/19}+{1/23}-{1/29}+{1/31}-$ etc. ubi numeri primi formae $4n-1$ habent signum positivum formae autem $4n+1$ signum negativum" (1775). E596 in the Enestrom index. Let $\chi$ be the nontrivial character modulo 4. Euler wants to know what $\sum_p \chi(p)/p$ is, either an exact expression or an approximation. He looks for analogies to the harmonic series and the series of reciprocals of the primes. Another reason he is interested in this is that if this series has a finite value (which is does, the best approximation Euler gets is 0.3349816 in section 27) then there are infinitely many primes congruent to 1 mod 4 and infinitely many primes congruent to 3 mod 4. In section 15 Euler gives the Euler product for the L(chi,1). As a modern mathematical appendix appendix, I have written a proof following Davenport that the series $\sum_p \frac{\chi(p)}{p}$ converges. This involves applications of summation by parts, and uses Chebyshev's estimate for the second Chebyshev function (summing the von Mangoldt function).
[ { "version": "v1", "created": "Sun, 19 Aug 2007 22:08:24 GMT" }, { "version": "v2", "created": "Sun, 19 Nov 2017 02:14:59 GMT" }, { "version": "v3", "created": "Wed, 22 Nov 2017 02:25:02 GMT" } ]
2017-11-23T00:00:00
[ [ "Euler", "Leonhard", "" ] ]
0708.2565
Yuri Serebrennikov
Yuri A. Serebrennikov
Coupling of electron rotation with spin in semiconductors
Will appear in Phys. Lett. A
Phys. Lett. A 372, 1106 (2008)
10.1016/j.physleta.2007.09.001
null
cond-mat.mes-hall
null
Account of an intrinsic spin-orbit coupling in the valence bands of common semiconductors yields the scalar spin-orbit-rotation term in the effective-mass Hamiltonian of the conduction-band electron. This result is obtained within the multiband envelope function approximation. Fundamentally, the spin-orbit-rotation coupling can be described in purely geometric terms as a consequence of the difference in the Berry phase acquired by the components of the spin-orbitally mixed Kramers-doublet during its cyclic evolution in the reciprocal momentum space.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 22:12:43 GMT" }, { "version": "v2", "created": "Sun, 30 Sep 2007 16:47:09 GMT" } ]
2009-11-13T00:00:00
[ [ "Serebrennikov", "Yuri A.", "" ] ]
0708.2566
Taesup Moon
Taesup Moon, Tsachy Weissman
Discrete Denoising with Shifts
30 pages, 3 figures, submitted to IEEE Trans. Inform. Theory
null
10.1109/TIT.2009.2030461
null
cs.IT math.IT
null
We introduce S-DUDE, a new algorithm for denoising DMC-corrupted data. The algorithm, which generalizes the recently introduced DUDE (Discrete Universal DEnoiser) of Weissman et al., aims to compete with a genie that has access, in addition to the noisy data, also to the underlying clean data, and can choose to switch, up to $m$ times, between sliding window denoisers in a way that minimizes the overall loss. When the underlying data form an individual sequence, we show that the S-DUDE performs essentially as well as this genie, provided that $m$ is sub-linear in the size of the data. When the clean data is emitted by a piecewise stationary process, we show that the S-DUDE achieves the optimum distribution-dependent performance, provided that the same sub-linearity condition is imposed on the number of switches. To further substantiate the universal optimality of the S-DUDE, we show that when the number of switches is allowed to grow linearly with the size of the data, \emph{any} (sequence of) scheme(s) fails to compete in the above senses. Using dynamic programming, we derive an efficient implementation of the S-DUDE, which has complexity (time and memory) growing only linearly with the data size and the number of switches $m$. Preliminary experimental results are presented, suggesting that S-DUDE has the capacity to significantly improve on the performance attained by the original DUDE in applications where the nature of the data abruptly changes in time (or space), as is often the case in practice.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 03:00:20 GMT" } ]
2016-11-17T00:00:00
[ [ "Moon", "Taesup", "" ], [ "Weissman", "Tsachy", "" ] ]
0708.2567
Todd K. Timberlake
Todd Timberlake and Jeffery Tucker
Is there quantum chaos in the prime numbers?
13 pages, 6 figures, 1 table, submitted to Physica A (We have extended the paper to include more statistical results and discussion.)
null
null
null
quant-ph
null
A statistical analysis of the prime numbers indicates possible traces of quantum chaos. We have computed the nearest neighbor spacing distribution, number variance, skewness, and excess for sequences of the first N primes for various values of N. All four statistical measures clearly show a transition from random matrix statistics at small N toward Poisson statistics at large N. In addition, the number variance saturates at large lengths as is common for eigenvalue sequences. This data can be given a physical interpretation if the primes are thought of as eigenvalues of a quantum system whose classical dynamics is chaotic at low energy but regular at high energy. We discuss some difficulties with this interpretation in an attempt to clarify what kind of physical system might have the primes as its quantum eigenvalues.
[ { "version": "v1", "created": "Sun, 19 Aug 2007 23:33:32 GMT" }, { "version": "v2", "created": "Mon, 7 Jan 2008 15:23:25 GMT" } ]
2008-01-07T00:00:00
[ [ "Timberlake", "Todd", "" ], [ "Tucker", "Jeffery", "" ] ]
0708.2568
Oisin A. P. Mac Conamhna
Oisin A. P. Mac Conamhna
Spacetime singularity resolution by M-theory fivebranes: calibrated geometry, Anti-de Sitter solutions and special holonomy metrics
1+52 pages
Commun.Math.Phys.284:345-389,2008
10.1007/s00220-008-0570-x
Imperial/TP/2007/OC/03
hep-th
null
The supergravity description of various configurations of supersymmetric M-fivebranes wrapped on calibrated cycles of special holonomy manifolds is studied. The description is provided by solutions of eleven-dimensional supergravity which interpolate smoothly between a special holonomy manifold and an event horizon with Anti-de Sitter geometry. For known examples of Anti-de Sitter solutions, the associated special holonomy metric is derived. One explicit Anti-de Sitter solution of M-theory is so treated for fivebranes wrapping each of the following cycles: K\"{a}hler cycles in Calabi-Yau two-, three- and four-folds; special lagrangian cycles in three- and four-folds; associative three- and co-associative four-cycles in $G_2$ manifolds; complex lagrangian four-cycles in $Sp(2)$ manifolds; and Cayley four-cycles in $Spin(7)$ manifolds. In each case, the associated special holonomy metric is singular, and is a hyperbolic analogue of a known metric. The analogous known metrics are respectively: Eguchi-Hanson, the resolved conifold and the four-fold resolved conifold; the deformed conifold, and the Stenzel four-fold metric; the Bryant-Salamon-Gibbons-Page-Pope $G_2$ metrics on an $\mathbb{R}^4$ bundle over $S^3$, and an $\mathbb{R}^3$ bundle over $S^4$ or $\mathbb{CP}^2$; the Calabi hyper-K\"{a}hler metric on $T^*\mathbb{CP}^2$; and the Bryant-Salamon-Gibbons-Page-Pope $Spin(7)$ metric on an $\mathbb{R}^4$ bundle over $S^4$. By the AdS/CFT correspondence, a conformal field theory is associated to each of the new singular special holonomy metrics, and defines the quantum gravitational physics of the resolution of their singularities.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 15:34:50 GMT" } ]
2008-11-26T00:00:00
[ [ "Mac Conamhna", "Oisin A. P.", "" ] ]
0708.2569
R Dimitric Dr.
Radoslav Dimitric
Algebraic Compactness OF $\prod M_\alpha / \oplus M_\alpha$
null
Internat. J. Pure Applied Math, 10(2004), No.3, 203-206
null
null
math.AC math.GR math.LO math.RA
null
In this note, we are working within the category $\rmod$ of (unitary, left) $R$-modules, where $R$ is a {\bf countable} ring. It is well known (see e.g. Kie{\l}pi\'nski & Simson [5], Theorem 2.2) that the latter condition implies that the (left) pure global dimension of $R$ is at most 1. Given an infinite index set $A$, and a family $M_\al\in\rmod$, $\al\in A$ we are concerned with the conditions as to when the $R$-module $$\prod/\coprod=\prod_{\al\in A}M_\al/\bigoplus_{\al\in A}M_\al$$ is or is not algebraically compact. There are a number of special results regarding this question and this note is meant to be an addition to and a generalization of the set of these results. Whether the module in the title is algebraically compact or not depends on the numbers of algebraically compact and non-compact modules among the components $M_\al$.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 00:19:04 GMT" } ]
2007-08-21T00:00:00
[ [ "Dimitric", "Radoslav", "" ] ]
0708.2570
R Dimitric Dr.
Radoslav Dimitric
A Note on Surjective Inverse Systems
null
Internat. J. Pure Applied Math., 10(2004), No.3, 349-356
null
null
math.CT math.AC math.GR math.LO math.RA
null
Given an upward directed set $I$ we consider surjective $I$-inverse systems $\{X_\al,f_{\al\be}:X_\be\lra X_\al| \al\leq\be\in I\}$, namely those inverse systems that have all $f_{\al\be}$ surjective. A number of properties of $I$-inverse systems have been investigated; such are the Mittag-Leffler condition, investigated by Grothendieck and flabby and semi-flabby $I$-inverse systems studied by Jensen. We note that flabby implies semi-flabby implies surjective implies Mittag-Leffler. Some of the results about surjective inverse systems have been known for some time. The aim of this note is to give a series of equivalent statements and implications involving surjective inverse systems and the systems satisfying the Mittag-Leffler condition, together with improvements of established results, as well as their relationships with the already known, but scattered facts. The most prominent results relate cardinalities of the index sets with right exactness of the inverse limit functor and the non-vanishing of the inverse limit -- connections related to cohomological dimensions.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 00:35:05 GMT" } ]
2007-08-21T00:00:00
[ [ "Dimitric", "Radoslav", "" ] ]
0708.2571
Milton Chowdhury
M. M. Chowdhury
On the Security of the Cha-Ko-Lee-Han-Cheon Braid Group Public Key Cryptosystem
null
null
null
null
cs.CR
null
We show that a number of cryptographic protocols using non-commutative semigroups including the Cha-Ko-Lee-Han-Cheon braid group public-key cryptosystem and related public-key cryptosystems such as the Shpilrain-Ushakov public-key cryptosystems are based on the MSCSP.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 00:47:15 GMT" }, { "version": "v2", "created": "Wed, 22 Aug 2007 12:58:05 GMT" }, { "version": "v3", "created": "Thu, 23 Aug 2007 02:54:51 GMT" }, { "version": "v4", "created": "Fri, 24 Aug 2007 00:56:05 GMT" }, { "version": "v5", "created": "Thu, 15 Nov 2007 22:28:36 GMT" } ]
2007-11-16T00:00:00
[ [ "Chowdhury", "M. M.", "" ] ]
0708.2572
William Y. C. Chen
William Y. C. Chen and Ernest X. W. Xia
The Ratio Monotonicity of the $q$-Derangement Numbers
16 pages. log-concavity possibly except for one term is added as a corollary
null
null
null
math.CO
null
We show that the $q$-derangement numbers satisfy a ratio monotone property, which is analogous to the log-concavity and is stronger than the spiral property and the unimodality.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 00:51:07 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 10:09:29 GMT" }, { "version": "v3", "created": "Thu, 4 Oct 2007 03:56:28 GMT" } ]
2007-10-04T00:00:00
[ [ "Chen", "William Y. C.", "" ], [ "Xia", "Ernest X. W.", "" ] ]
0708.2573
Michael Thoennessen
N. Frank, T. Baumann, D. Bazin, J. Brown, P.A. DeYoung, J. E. Finck, A. Gade, J. Hinnefeld, R. Howes, J.-L. Lecouey, B. Luther, W. A. Peters, H. Scheit, A. Schiller, M. Thoennessen
Exploring Neutron-Rich Oxygen Isotopes with MoNA
6 pages, 4 Figures, submitted to Proc. Int. Conf. on Proton Emitting Nuclei and Related Topics, PROCON07
AIPConf.Proc.961:143-148,2007
10.1063/1.2827247
null
nucl-ex
null
The Modular Neutron Array (MoNA) was used in conjunction with a large-gap dipole magnet (Sweeper) to measure neutron-unbound states in oxygen isotopes close to the neutron dripline. While no excited states were observed in 24O, a resonance at 45(2) keV above the neutron separation energy was observed in 23O.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 00:59:15 GMT" } ]
2008-11-26T00:00:00
[ [ "Frank", "N.", "" ], [ "Baumann", "T.", "" ], [ "Bazin", "D.", "" ], [ "Brown", "J.", "" ], [ "DeYoung", "P. A.", "" ], [ "Finck", "J. E.", "" ], [ "Gade", "A.", "" ], [ "Hinnefeld", "J.", "" ], [ "Howes", "R.", "" ], [ "Lecouey", "J. -L.", "" ], [ "Luther", "B.", "" ], [ "Peters", "W. A.", "" ], [ "Scheit", "H.", "" ], [ "Schiller", "A.", "" ], [ "Thoennessen", "M.", "" ] ]
0708.2574
William Y. C. Chen
William Y. C. Chen, Carol J. Wang and Larry X. W. Wang
The Limiting Distribution of the Coefficients of the $q$-Catalan Numbers
13 pages
null
null
null
math.CO
null
We show that the limiting distributions of the coefficients of the $q$-Catalan numbers and the generalized $q$-Catalan numbers are normal. Despite the fact that these coefficients are not unimodal for small $n$, we conjecture that for sufficiently large $n$, the coefficients are unimodal and even log-concave except for a few terms of the head and tail.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 01:00:04 GMT" } ]
2007-08-21T00:00:00
[ [ "Chen", "William Y. C.", "" ], [ "Wang", "Carol J.", "" ], [ "Wang", "Larry X. W.", "" ] ]
0708.2575
Gregory Wornell
Uri Erez, Mitchell D. Trott and Gregory W. Wornell
Rateless Coding for Gaussian Channels
18 pages
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A rateless code-i.e., a rate-compatible family of codes-has the property that codewords of the higher rate codes are prefixes of those of the lower rate ones. A perfect family of such codes is one in which each of the codes in the family is capacity-achieving. We show by construction that perfect rateless codes with low-complexity decoding algorithms exist for additive white Gaussian noise channels. Our construction involves the use of layered encoding and successive decoding, together with repetition using time-varying layer weights. As an illustration of our framework, we design a practical three-rate code family. We further construct rich sets of near-perfect rateless codes within our architecture that require either significantly fewer layers or lower complexity than their perfect counterparts. Variations of the basic construction are also developed, including one for time-varying channels in which there is no a priori stochastic model.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 01:32:42 GMT" }, { "version": "v2", "created": "Fri, 3 Jun 2011 21:04:26 GMT" } ]
2011-06-07T00:00:00
[ [ "Erez", "Uri", "" ], [ "Trott", "Mitchell D.", "" ], [ "Wornell", "Gregory W.", "" ] ]
0708.2576
Gerardo Juan Manuel Luna
G. J. M. Luna and J. L. Sokoloski
The Nature of the Hard-X-Ray Emitting Symbiotic Star RT Cru
3 figures, accepted for publication in ApJ
null
10.1086/522576
null
astro-ph
null
We describe Chandra High-Energy Transmission Grating Spectrometer observations of RT Cru, the first of a new sub-class of symbiotic stars that appear to contain white dwarfs (WDs) capable of producing hard X-ray emission out to greater than 50 keV. The production of such hard X-ray emission from the objects in this sub-class (which also includes CD -57 3057, T CrB, and CH Cyg) challenges our understanding of accreting WDs. We find that the 0.3 -- 8.0 keV X-ray spectrum of RT Cru emanates from an isobaric cooling flow, as in the optically thin accretion-disk boundary layers of some dwarf novae. The parameters of the spectral fit confirm that the compact accretor is a WD, and they are consistent with the WD being massive. We detect rapid, stochastic variability from the X-ray emission below 4 keV. The combination of flickering variability and a cooling-flow spectrum indicates that RT Cru is likely powered by accretion through a disk. Whereas the cataclysmic variable stars with the hardest X-ray emission are typically magnetic accretors with X-ray flux modulated at the WD spin period, we find that the X-ray emission from RT Cru is not pulsed. RT Cru therefore shows no evidence for magnetically channeled accretion, consistent with our interpretation that the Chandra spectrum arises from an accretion-disk boundary layer.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 01:40:22 GMT" }, { "version": "v2", "created": "Fri, 24 Aug 2007 02:09:54 GMT" } ]
2009-11-13T00:00:00
[ [ "Luna", "G. J. M.", "" ], [ "Sokoloski", "J. L.", "" ] ]
0708.2577
Roman Kezerashvili Dr.
Roman Ya. Kezerashvili, Candido Cabo, Djafar K. Mynbaev
The Transfer of Knowledge from Physics and Mathematics to Engineering Applications
Proceedings of the International Conference on Knowledge Generation, Communication and Management: KGCM 2007, July 8-11, 2007. Orlando, Florida, USA, Vol. 3 (2007) 234-239
null
null
null
physics.ed-ph physics.gen-ph
null
The objective of this paper is to describe a development of an innovative approach to enable students studying science, technology, engineering, and mathematics (STEM) to apply the concepts learned in physics and mathematics to engineering problem-solving challenges. Our goal is to facilitate students transfer of knowledge from theory to engineering applications, thereby increasing student academic performance, retention, persistence, and graduation. To achieve the goal we are creating a virtual community of students and faculty as a vehicle for promoting the transfer of knowledge using e-learning and e-teaching mechanisms.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 02:34:04 GMT" } ]
2007-08-21T00:00:00
[ [ "Kezerashvili", "Roman Ya.", "" ], [ "Cabo", "Candido", "" ], [ "Mynbaev", "Djafar K.", "" ] ]
0708.2578
Linhua Jiang
Linhua Jiang, Xiaohui Fan, James Annis, Robert H. Becker, Richard L. White, Kuenley Chiu, Huan Lin, Robert H. Lupton, Gordon T. Richards, Michael A. Strauss, Sebastian Jester and Donald P. Schneider
A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21
12 pages (emulateapj); submitted to AJ
Astron.J.135:1057-1066,2008
10.1088/0004-6256/135/3/1057
null
astro-ph
null
We present the discovery of five quasars at z~6 selected from 260 deg^2 of the Sloan Digital Sky Survey (SDSS) southern survey, a deep imaging survey obtained by repeatedly scanning a stripe along the Celestial Equator. The five quasars with 20<z_{AB}<21 are 1-2 magnitudes fainter than the luminous z~6 quasars discovered in the SDSS main survey. One of them was independently discovered by the UKIRT Infrared Deep Sky Survey. These quasars, combined with another z~6 quasar known in this region, make a complete flux- limited quasar sample at z_{AB}<21. The sample spans the redshift range 5.85<z<6.12 and the luminosity range -26.5<M_{1450}<-25.4 (H_0=70 km s^{-1} Mpc^{-1}, Omega_{m}=0.3, and Omega_{Lambda}=0.7). We use the 1/V_{a} method to determine that the comoving quasar spatial density at <z>=6.0 and <M_{1450}>=-25.8 is (5.0+/-2.1) x 10^{-9} Mpc^{-3} mag^{-1}. We model the bright-end quasar luminosity function (QLF) at z~6 as a power law Phi(L_{1450}) \propto L_{1450}^{beta}. The slope beta calculated from a combination of our sample and the luminous SDSS quasar sample is -3.1+/-0.4, significantly steeper than the slope of the QLF at z~4. Based on the derived QLF, we find that the quasar/AGN population cannot provide enough photons to ionize the intergalactic medium (IGM) at z~6 unless the IGM is very homogeneous and the luminosity (L*_{1450}) at which the QLF power law breaks is very low.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 02:36:21 GMT" } ]
2008-11-26T00:00:00
[ [ "Jiang", "Linhua", "" ], [ "Fan", "Xiaohui", "" ], [ "Annis", "James", "" ], [ "Becker", "Robert H.", "" ], [ "White", "Richard L.", "" ], [ "Chiu", "Kuenley", "" ], [ "Lin", "Huan", "" ], [ "Lupton", "Robert H.", "" ], [ "Richards", "Gordon T.", "" ], [ "Strauss", "Michael A.", "" ], [ "Jester", "Sebastian", "" ], [ "Schneider", "Donald P.", "" ] ]
0708.2579
Miuchi Kentaro
Kentaro Miuchi, Kaori Hattori, Shigeto Kabuki, Hidetoshi Kubo, Shunsuke Kurosawa, Hironobu Nishimura, Yoko Okada, Atsushi Takada, Toru Tanimori, Ken'ichi Tsuchiya, Kazuki Ueno, Hiroyuki Sekiya, Atsushi Takeda
Direction-sensitive dark matter search results in a surface laboratory
9 figures, accepted for publication in Phys. Lett. B
Phys.Lett.B654:58-64,2007
10.1016/j.physletb.2007.08.042
null
astro-ph
null
We developed a three-dimensional gaseous tracking device and performed a direction-sensitive dark matter search in a surface laboratory. By using 150 Torr carbon-tetrafluoride (CF_4 gas), we obtained a sky map drawn with the recoil directions of the carbon and fluorine nuclei, and set the first limit on the spin-dependent WIMP (Weakly Interacting Massive Particles)-proton cross section by a direction-sensitive method. Thus, we showed that a WIMP-search experiment with a gaseous tracking device can actually set limits. Furthermore, we demonstrated that this method will potentially play a certain role in revealing the nature of dark matter when a low-background large-volume detector is developed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 02:59:41 GMT" } ]
2008-11-26T00:00:00
[ [ "Miuchi", "Kentaro", "" ], [ "Hattori", "Kaori", "" ], [ "Kabuki", "Shigeto", "" ], [ "Kubo", "Hidetoshi", "" ], [ "Kurosawa", "Shunsuke", "" ], [ "Nishimura", "Hironobu", "" ], [ "Okada", "Yoko", "" ], [ "Takada", "Atsushi", "" ], [ "Tanimori", "Toru", "" ], [ "Tsuchiya", "Ken'ichi", "" ], [ "Ueno", "Kazuki", "" ], [ "Sekiya", "Hiroyuki", "" ], [ "Takeda", "Atsushi", "" ] ]
0708.2580
Leonard Gamberg
Leonard P. Gamberg, Gary R. Goldstein and Marc Schlegel
Flavor Dependence of T-odd PDFs
To appear in the proceedings of 15th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2007), Munich, Germany, 16-20 Apr 2007
null
null
null
hep-ph
null
The flavor dependence of the naive time reversal odd (``T-odd'') parton distributions for $u$- and $d$-quarks are explored in the spectator model. The flavor dependence of $h_{1}^{\perp}$ is of significance for the analysis of the azimuthal $\cos(2\phi)$ asymmetries in unpolarized SIDIS and DY-processes, as well as for the overall physical understanding of the distribution of transversely polarized quarks in unpolarized nucleons. As a by-product of the formalism, we calculate the chiral-odd but ``T-even'' function $h_{1L}^{\perp}$ which enables us to present a prediction for the single spin asymmetry $A_{UL}^{\sin(2\phi)}$ for a longitudinally polarized target in SIDIS.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 03:25:00 GMT" } ]
2007-08-21T00:00:00
[ [ "Gamberg", "Leonard P.", "" ], [ "Goldstein", "Gary R.", "" ], [ "Schlegel", "Marc", "" ] ]
0708.2581
Ming-Tsung Lee
Ming-Tsung Lee and Wei-Min Zhang
Non-equilibrium theory of charge qubit decoherence in the quantum point contact measurement
14 pages, 7 figures
null
10.1063/1.3036114
null
cond-mat.mes-hall
null
A non-equilibrium theory describing the charge qubit dynamics measured by a quantum point contact is developed based on Schwinger-Keldysh's approach. Using the real-time diagram technique, we derive the master equation to all orders in perturbation expansions. The non-Markovian processes in the qubit dynamics is naturally taken into account. The qubit decoherence, in particular, the influence of the tunneling-electron fluctuation in the quantum point contact with a longer time correlation, is studied in the framework. We consider the Lorentzian-type spectral density to characterize the channel mixture of the electron tunneling processes induced by the measurement and determine the correlation time scale of the tunneling-electron fluctuation. The result shows that as the quantum point contact is casted with a narrower profile of the spectral density, tunneling electrons can propagate with a longer time correlation and lead to the non-Markovian processes of the qubit dynamics. The qubit electron in the charge qubit will be driven coherently. The quantum point contact measurement with the minimum deviation of the electron tunneling processes prevents the qubit state from the decoherence.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 03:25:16 GMT" }, { "version": "v2", "created": "Sat, 19 Apr 2008 17:24:49 GMT" } ]
2009-11-13T00:00:00
[ [ "Lee", "Ming-Tsung", "" ], [ "Zhang", "Wei-Min", "" ] ]
0708.2582
H. J. Xiang
H. J. Xiang and M.-H. Whangbo
Density Functional Theory Characterization of the Multiferroicity in Spin Spiral Chain Cuprates
Phys. Rev. Lett., in print
Phys. Rev. Lett. 99, 257203 (2007)
10.1103/PhysRevLett.99.257203
null
cond-mat.mtrl-sci cond-mat.str-el
null
The ferroelectricity of the spiral magnets LiCu2O2 and LiCuVO4 was examined by calculating the electric polarizations of their spin spiral states on the basis of density functional theory with spin-orbit coupling. Our work unambiguously reveals that spin-orbit coupling is responsible for the ferroelectricity with the primary contribution from the spin-orbit coupling on the Cu sites, but the asymmetric density distribution responsible for the electric polarization occurs mainly around the O atoms. The electric polarization is calculated to be much greater for the ab- than for the bc-plane spin spiral. The observed spin-spiral plane is found to be consistent with the observed direction of the electric polarization for LiCuVO4, but inconsistent for LiCu2O2.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 04:09:39 GMT" }, { "version": "v2", "created": "Fri, 2 Nov 2007 20:55:55 GMT" } ]
2011-11-10T00:00:00
[ [ "Xiang", "H. J.", "" ], [ "Whangbo", "M. -H.", "" ] ]
0708.2583
PanKi Kim
Panki Kim, Renming Song and Zoran Vondracek
Boundary Harnack Principle for Subordinate Brownian Motions
34 pages
null
null
null
math.PR
null
We establish a boundary Harnack principle for a large class of subordinate Brownian motion, including mixtures of symmetric stable processes, in bounded $\kappa$-fat open set (disconnected analogue of John domains). As an application of the boundary Harnack principle, we identify the Martin boundary and the minimal Martin boundary of bounded $\kappa$-fat open sets with respect to these processes with their Euclidean boundary.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 04:16:01 GMT" } ]
2007-08-21T00:00:00
[ [ "Kim", "Panki", "" ], [ "Song", "Renming", "" ], [ "Vondracek", "Zoran", "" ] ]
0708.2584
Seiichiro Tani
Seiichiro Tani
Claw Finding Algorithms Using Quantum Walk
12 pages. Introduction revised. A reference added. Weak lower bound deleted
Theoretical Computer Science, 410(50): 5285-5297 (2009)
10.1016/j.tcs.2009.08.030
null
quant-ph cs.CC
null
The claw finding problem has been studied in terms of query complexity as one of the problems closely connected to cryptography. For given two functions, f and g, as an oracle which have domains of size N and M (N<=M), respectively, and the same range, the goal of the problem is to find x and y such that f(x)=g(y). This paper describes an optimal algorithm using quantum walk that solves this problem. Our algorithm can be generalized to find a claw of k functions for any constant integer k>1, where the domains of the functions may have different size.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:56:12 GMT" }, { "version": "v2", "created": "Mon, 3 Mar 2008 13:23:09 GMT" } ]
2011-06-17T00:00:00
[ [ "Tani", "Seiichiro", "" ] ]
0708.2585
Hiroaki Yamada
Shu-ichi Kinoshita, Kazumoto Iguchi, Hiroaki S. Yamada
Robustness of Attractor States in Complex Networks with Scale-free Topology
9 pages, 5 figures
null
null
null
cond-mat.dis-nn
null
We study the intrinsic properties of attractors in the Boolean dynamics in complex network with scale-free topology, comparing with those of the so-called random Kauffman networks. We have numerically investigated the frozen and relevant nodes for each attractor, and the robustness of the attractors to the perturbation that flips the state of a single node of attractors in the relatively small network ($N=30 \sim 200$). It is shown that the rate of frozen nodes in the complex networks with scale-free topology is larger than that in the random Kauffman model. Furthermore, we have found that in the complex scale-free networks with fluctuations of in-degree number the attractors are more sensitive to the state flip of a highly connected node than to the state flip of a less connected node.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:33:34 GMT" } ]
2007-08-21T00:00:00
[ [ "Kinoshita", "Shu-ichi", "" ], [ "Iguchi", "Kazumoto", "" ], [ "Yamada", "Hiroaki S.", "" ] ]
0708.2586
Marco Casolino
M. Casolino, F. Altamura, M. Minori, P. Picozza, C. Fuglesang, A. Galper, A. Popov, V. Benghin, V. M. Petrov, A. Nagamatsu, T. Berger, G. Reitz, M. Durante, M. Pugliese, V. Roca, L. Sihver F. Cucinotta, E. Semones, M. Shavers, V. Guarnieri, C. Lobascio, D. Castagnolo, R. Fortezza
The ALTCRISS project on board the International Space Station
Accepted for publication on Advances in Space Research http://dx.doi.org/10.1016/j.asr.2007.04.037
Adv.Space Res.40:1746-1753,2007
10.1016/j.asr.2007.04.037
null
astro-ph
null
The Altcriss project aims to perform a long term survey of the radiation environment on board the International Space Station. Measurements are being performed with active and passive devices in different locations and orientations of the Russian segment of the station. The goal is to perform a detailed evaluation of the differences in particle fluence and nuclear composition due to different shielding material and attitude of the station. The Sileye-3/Alteino detector is used to identify nuclei up to Iron in the energy range above 60 MeV/n. Several passive dosimeters (TLDs, CR39) are also placed in the same location of Sileye-3 detector. Polyethylene shielding is periodically interposed in front of the detectors to evaluate the effectiveness of shielding on the nuclear component of the cosmic radiation. The project was submitted to ESA in reply to the AO in the Life and Physical Science of 2004 and data taking began in December 2005. Dosimeters and data cards are rotated every six months: up to now three launches of dosimeters and data cards have been performed and have been returned with the end of expedition 12 and 13.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 06:01:39 GMT" } ]
2010-03-17T00:00:00
[ [ "Casolino", "M.", "" ], [ "Altamura", "F.", "" ], [ "Minori", "M.", "" ], [ "Picozza", "P.", "" ], [ "Fuglesang", "C.", "" ], [ "Galper", "A.", "" ], [ "Popov", "A.", "" ], [ "Benghin", "V.", "" ], [ "Petrov", "V. M.", "" ], [ "Nagamatsu", "A.", "" ], [ "Berger", "T.", "" ], [ "Reitz", "G.", "" ], [ "Durante", "M.", "" ], [ "Pugliese", "M.", "" ], [ "Roca", "V.", "" ], [ "Cucinotta", "L. Sihver F.", "" ], [ "Semones", "E.", "" ], [ "Shavers", "M.", "" ], [ "Guarnieri", "V.", "" ], [ "Lobascio", "C.", "" ], [ "Castagnolo", "D.", "" ], [ "Fortezza", "R.", "" ] ]
0708.2587
Marco Casolino
M. Casolino, N. De Simone, V. Di Felice, P. Picozza
Detection of the high energy component of Jovian electrons in Low Earth Orbit with the PAMELA experiment
On behalf of PAMELA collaboration. Accepted for publication on Advances in Space Research
Adv.SpaceRes.41:168-173,2008
10.1016/j.asr.2007.07.024
null
astro-ph
null
The PAMELA experiment is devoted to the study of cosmic rays in Low Earth Orbit with an apparatus optimized to perform a precise determination of the galactic antimatter component of c.r. It is constituted by a number of detectors built around a permanent magnet spectrometer. PAMELA was launched in space on June 15th 2006 on board the Russian Resurs-DK1 satellite for a mission duration of three years. The characteristics of the detectors, the long lifetime and the orbit of the satellite, will allow to address several aspects of cosmic-ray physics. In this work we discuss the observational capabilities of PAMELA to detect the electron component above 50 MeV. The magnetic spectrometer allows a detailed measurement of the energy spectrum of electrons of galactic and Jovian origin. Long term measurements and correlations with Earth-Jupiter 13 months synodic period will allow to separate these two contributions and to measure the primary electron Jovian component, dominant in the 50-70 MeV energy range. With this technique it will also be possible to study the contribution to the electron spectrum of Jovian e- reaccelerated up to 2 GeV at the Solar Wind Termination Shock.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 05:56:37 GMT" } ]
2008-11-26T00:00:00
[ [ "Casolino", "M.", "" ], [ "De Simone", "N.", "" ], [ "Di Felice", "V.", "" ], [ "Picozza", "P.", "" ] ]
0708.2588
Hong-Jian He
Hong-Jian He, Yu-Ping Kuang, Yong-Hui Qi, Bin Zhang (Tsinghua), Alexander Belyaev, R. Sekhar Chivukula, Neil D. Christensen, Alexander Pukhov, Elizabeth H. Simmons (MSU)
LHC Signatures of New Gauge Bosons in the Minimal Higgsless Model
5pp, Rapid Communication of PRD (in Press). Minor clarifications to stress the importance and broad interest of this work. (All results un-changed.)
Phys.Rev.D78:031701,2008
10.1103/PhysRevD.78.031701
TUHEP-TH-07162, MSUHEP-070817
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the LHC signatures of new gauge bosons in the gauge-invariant minimal Higgsless model. It predicts an extra pair of W_1 and Z_1 bosons which can be as light as ~400GeV and play a key role in the delay of unitarity violation. We analyze the W_1 signals in pp --> W_0Z_0Z_0 --> jj4\ell and pp --> jj W_0Z_0 --> jj3\ell\nu processes at the LHC, including the complete electroweak and QCD backgrounds. We reveal the complementarity between these two channels for discovering the W_1 boson, and demonstrate the LHC discovery potential over the full range of allowed W_1 mass.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 06:28:06 GMT" }, { "version": "v2", "created": "Tue, 1 Jul 2008 17:11:45 GMT" } ]
2008-11-26T00:00:00
[ [ "He", "Hong-Jian", "", "Tsinghua" ], [ "Kuang", "Yu-Ping", "", "Tsinghua" ], [ "Qi", "Yong-Hui", "", "Tsinghua" ], [ "Zhang", "Bin", "", "Tsinghua" ], [ "Belyaev", "Alexander", "", "MSU" ], [ "Chivukula", "R. Sekhar", "", "MSU" ], [ "Christensen", "Neil D.", "", "MSU" ], [ "Pukhov", "Alexander", "", "MSU" ], [ "Simmons", "Elizabeth H.", "", "MSU" ] ]
0708.2589
Michael Brunnbauer
Michael Brunnbauer
On manifolds satisfying stable systolic inequalities
15 pages; Theorem 1.4 is improved, the dependence on the intersection form is clearified
null
null
null
math.GT math.DG
null
We show that for closed orientable manifolds the $k$-dimensional stable systole admits a metric-independent volume bound if and only if there are cohomology classes of degree $k$ that generate cohomology in top-degree. Moreover, it turns out that in the nonorientable case such a bound does not exist for stable systoles of dimension at least two. Additionally, we prove that the stable systolic constant depends only on the image of the fundamental class in a suitable Eilenberg-Mac Lane space. Consequently, the stable $k$-systolic constant is completely determined by the multilinear intersection form on $k$-dimensional cohomology.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 06:55:14 GMT" }, { "version": "v2", "created": "Thu, 17 Apr 2008 14:36:22 GMT" } ]
2008-04-17T00:00:00
[ [ "Brunnbauer", "Michael", "" ] ]
0708.2590
Y. M. Cho
Y.M.Cho, J.H.Kim, S.W. Kim, J.H. Yoon
Hierarchy Problem, Dilatonic Fifth Force, and Origin of Mass
5 pages, 1 figure
null
null
null
hep-ph gr-qc hep-th
null
Based on the fact that the scalar curvature of the internal space determines the mass of the dilaton in higher-dimensional unified theories, we show how the dilaton mass can explain the origin of mass and resolve the hierarchy problem. Moreover, we show that cosmology puts a strong constraint on dilaton mass, and requires the scale of the internal space to be larger than $10^{-9} m$.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:05:02 GMT" }, { "version": "v2", "created": "Tue, 4 Dec 2007 10:48:20 GMT" } ]
2007-12-04T00:00:00
[ [ "Cho", "Y. M.", "" ], [ "Kim", "J. H.", "" ], [ "Kim", "S. W.", "" ], [ "Yoon", "J. H.", "" ] ]
0708.2591
Leonardo Rastelli
Leonardo Rastelli and Barton Zwiebach
The off-shell Veneziano amplitude in Schnabl gauge
48 pages, 10 figures. v2:acknowledgments added
JHEP 0801:018,2008
10.1088/1126-6708/2008/01/018
null
hep-th
null
We give a careful definition of the open string propagator in Schnabl gauge and present its worldsheet interpretation. The propagator requires two Schwinger parameters and contains the BRST operator. It builds surfaces by gluing strips of variable width to the left and to the right of off-shell states with contracted or expanded local frames. We evaluate explicitly the four-point amplitude of off-shell tachyons. The computation involves a subtle boundary term, crucial to enforce the correct exchange symmetries. Interestingly, the familiar on-shell physics emerges even though string diagrams produce Riemann surfaces more than once. Off-shell, the amplitudes do not factorize over intermediate on-shell states.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:07:29 GMT" }, { "version": "v2", "created": "Fri, 9 Nov 2007 04:07:42 GMT" } ]
2009-06-11T00:00:00
[ [ "Rastelli", "Leonardo", "" ], [ "Zwiebach", "Barton", "" ] ]
0708.2592
Prof. Dr. M. W. Wu
K. Shen, M. W. Wu
Triplet-singlet relaxation in semiconductor single and double quantum dots
7 pages, 4 figures, PRB in press
Phys. Rev. B 76, 235313 (2007).
10.1103/PhysRevB.76.235313
null
cond-mat.mtrl-sci cond-mat.mes-hall
null
We study the triplet-singlet relaxation in two-electron semiconductor quantum dots. Both single dots and vertically coupled double dots are discussed. In our work, the electron-electron Coulomb interaction, which plays an important role in the electronic structure, is included. The spin mixing is caused by spin-orbit coupling which is the key to the triplet-singlet relaxation. We show that the selection rule widely used in the literature is incorrect unless near the crossing/anticrossing point in single quantum dots. The triplet/singlet relaxation in double quantum dots can be markedly changed by varying barrier height, inter-dot distance, external magnetic field and dot size.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:35:56 GMT" }, { "version": "v2", "created": "Tue, 27 Nov 2007 03:37:30 GMT" } ]
2007-12-18T00:00:00
[ [ "Shen", "K.", "" ], [ "Wu", "M. W.", "" ] ]
0708.2593
Mushfiq Ahmad
Mushfiq Ahmad
Derivation of Relativistic law of Addition of Velocities from Superposition of Eigenfunctions and Discreteness
13 pages, no figures
null
null
null
physics.gen-ph
null
We have defined a slowness, s, as the reciprocal conjugate of velocity, v. s = -ih/v. We have shown that Einstein's postulate (v has an upper limit) implies that s is discrete. A velocity operator is defined as the derivative with respect to s. Superposition of corresponding Eigenfunctions give Galilean law of addition of velocities. We have replaced the differential operator by the corresponding finite difference symmetric operator. We have shown that superposition of corresponding discrete Eigenfunctions give relativistic law of addition of velocities. A reciprocal symmetric number system is developed and with the help of this number system we have shown the relation between superposition and relativistic law of addition of velocities.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:16:51 GMT" } ]
2007-08-21T00:00:00
[ [ "Ahmad", "Mushfiq", "" ] ]
0708.2594
Michel Salzet
M. Salzet (NA)
Molecular Aspect of Annelid Neuroendocrine system
null
Invertebrate Neuropeptides and Hormones: Basic Knowledge and Recent Advances, Transworld Research Network (Ed.) (2007) 19
null
null
q-bio.NC
null
Hormonal processes along with enzymatic processing similar to that found in vertebrates occur in annelids. Amino acid sequence determination of annelids precursor gene products reveals the presence of the respective peptides that exhibit high sequence identity to their mammalian counterparts. Furthermore, these neuropeptides exert similar physiological function in annelids than the ones found in vertebrates. In this respect, the high conservation in course of evolution of these molecules families reflects their importance. Nevertheless, some specific neuropeptides to annelids or invertebrates have also been in these animals.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:20:36 GMT" } ]
2007-08-21T00:00:00
[ [ "Salzet", "M.", "", "NA" ] ]
0708.2595
Denis Khomitsky
D.V. Khomitsky
Manipulating the spin texture in spin-orbit superlattice by terahertz radiation
5 pages, 3 figures
Phys. Rev. B 77, 113313 (2008)
10.1103/PhysRevB.77.113313
null
cond-mat.mes-hall
null
The spin texture in a gate-controlled superlattice with Rashba spin-orbit coupling is studied in the presence of external terahertz radiation causing the superlattice miniband transitions. It is shown that the local distribution of spin density can be flipped by tuning the radiation intensity, allowing the controlled coupling of spins and photons with different polarizations.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:42:47 GMT" }, { "version": "v2", "created": "Wed, 2 Apr 2008 12:11:00 GMT" } ]
2009-11-13T00:00:00
[ [ "Khomitsky", "D. V.", "" ] ]
0708.2596
YuanYao Lin Mr
YuanYao Lin, Ray-Kuang Lee, Yuri S. Kivshar
Soliton transverse instabilities in nonlocal nonlinear media
3 pages, 3 figures
null
10.1364/JOSAB.25.000576
null
physics.optics
null
We analyze the transverse instabilities of spatial bright solitons in nonlocal nonlinear media, both analytically and numerically. We demonstrate that the nonlocal nonlinear response leads to a dramatic suppression of the transverse instability of the soliton stripes, and we derive the asymptotic expressions for the instability growth rate in both short- and long-wave approximations.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 07:51:59 GMT" } ]
2009-11-13T00:00:00
[ [ "Lin", "YuanYao", "" ], [ "Lee", "Ray-Kuang", "" ], [ "Kivshar", "Yuri S.", "" ] ]
0708.2597
Axel Fingerle
A. Fingerle, S. Herminghaus
Mechanisms of dissipation in wet granular matter
null
null
null
null
cond-mat.soft
null
The impact dynamics between wet surfaces, which dominates the mechanical properties of wet granular matter, is studied both experimentally and theoretically. It is shown that the hysteretic formation and rupture of liquid capillary bridges between adjacent grains accounts reasonably well for most relevant cases of wet granular matter. The various dissipation mechanisms are discussed with particular emphasis on their relevance. Variations of the rupture energy loss with the impact energy are quantified and discussed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 19:23:00 GMT" } ]
2007-08-21T00:00:00
[ [ "Fingerle", "A.", "" ], [ "Herminghaus", "S.", "" ] ]
0708.2598
Xinping Xu
Xinping Xu, Feng Liu and Lianshou Liu
Mechanism for linear preferential attachment in growing networks
10 pages, 1 figure
Physica A 356(2005)662
10.1016/j.physa.2005.04.005
null
physics.data-an physics.soc-ph
null
The network properties of a graph ensemble subject to the constraints imposed by the expected degree sequence are studied. It is found that the linear preferential attachment is a fundamental rule, as it keeps the maximal entropy in sparse growing networks. This provides theoretical evidence in support of the linear preferential attachment widely exists in real networks and adopted as a crucial assumption in growing network models. Besides, in the sparse limit, we develop a method to calculate the degree correlation and clustering coefficient in our ensemble model, which is suitable for all kinds of sparse networks including the BA model, proposed by Barabasi and Albert.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:00:24 GMT" } ]
2009-11-13T00:00:00
[ [ "Xu", "Xinping", "" ], [ "Liu", "Feng", "" ], [ "Liu", "Lianshou", "" ] ]
0708.2599
Fabrizio Tavecchio
F. Tavecchio
Extragalactic jets on subpc and large scales
Proceedings of the 5th Stromlo Symposium: Disks, Winds, and Jets - from Planets to Quasars. Accepted, to be published in Astrophysics & Space Science
Astrophys.SpaceSci.311:247-255,2007
10.1007/s10509-007-9546-0
null
astro-ph
null
Jets can be probed in their innermost regions (d~0.1 pc) through the study of the relativistically-boosted emission of blazars. On the other extreme of spatial scales, the study of structure and dynamics of extragalactic relativistic jets received renewed impulse after the discovery, made by Chandra, of bright X-ray emission from regions at distances larger than hundreds of kpc from the central engine. At both scales it is thus possible to infer some of the basic parameters of the flow (speed, density, magnetic field intensity, power). After a brief review of the available observational evidence, I discuss how the comparison between the physical quantities independently derived at the two scales can be used to shed light on the global dynamics of the jet, from the innermost regions to the hundreds of kpc scale.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:02:50 GMT" } ]
2008-11-26T00:00:00
[ [ "Tavecchio", "F.", "" ] ]
0708.2600
Xinping Xu
Xinping Xu, Feng Liu and Wei Li
Growing small-world networks based on a modified BA model
4 pages, 4 figures
Chin.Phys.Lett 23(2006)750
10.1088/0256-307X/23/3/062
null
math-ph math.MP
null
We propose a simple growing model for the evolution of small-world networks. It is introduced as a modified BA model in which all the edges connected to the new nodes are made locally to the creator and its nearest neighbors. It is found that this model can produce small-world networks with power-law degree distributions. Properties of our model, including the degree distribution, clustering, and the average path length are compared with that of the BA model. Since most real networks are both scale-free and small-world networks, our model may provide a satisfactory description for empirical characteristics of real networks.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:15:21 GMT" } ]
2009-11-13T00:00:00
[ [ "Xu", "Xinping", "" ], [ "Liu", "Feng", "" ], [ "Li", "Wei", "" ] ]
0708.2601
Xinping Xu
Xinping Xu and Feng Liu
A novel configuration model for random graphs with given degree sequence
7 pages, 3 figures
Chinese Physics 16(2007)282
10.1088/1009-1963/16/2/002
null
math-ph math.MP
null
Recently, random graphs in which vertices are characterized by hidden variables controlling the establishment of edges between pairs of vertices have attracted much attention. Here, we present a specific realization of a class of random network models in which the connection probability between two vertices (i,j) is a specific function of degrees ki and kj. In the framework of the configuration model of random graphs, we find analytical expressions for the degree correlation and clustering as a function of the variance of the desired degree distribution. The expressions obtained are checked by means of numerical simulations. Possible applications of our model are discussed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:30:01 GMT" } ]
2009-11-13T00:00:00
[ [ "Xu", "Xinping", "" ], [ "Liu", "Feng", "" ] ]
0708.2602
Konstantin Arutyunov
K. Yu. Arutyunov
Negative magnetoresistance of ultra-narrow superconducting nanowires in the resistive state
10 pages including 2 figures
Physica C 468 (2008) 272--275
10.1016/j.physc.2007.08.027
null
cond-mat.supr-con
null
We present a phenomenological model qualitatively explaining negative magnetoresistance in quasi-one-dimensional superconducting channels in the resistive state. The model is based on the assumption that fluctuations of the order parameter (phase slips) are responsible for the finite effective resistance of a narrow superconducting wire sufficiently close to the critical temperature. Each fluctuation is accompanied by an instant formation of a quasi-normal region of the order of the non-equilibrium quasiparticle relaxation length 'pinned' to the core of the phase slip. The effective time-averaged voltage measured in experiment is a sum of two terms. First one is the conventional contribution linked to the rate of the fluctuations via the Josephson relation. Second term is the Ohmic contribution of this quasi-normal region. Depending on material properties of the wire, there might be a range of magnetic fields where the first term is not much affected, while the second term is effectively suppressed contributing to the experimentally observed negative magnetoresistance.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:33:36 GMT" }, { "version": "v2", "created": "Wed, 22 Aug 2007 10:14:36 GMT" } ]
2009-04-07T00:00:00
[ [ "Arutyunov", "K. Yu.", "" ] ]
0708.2603
Daniele Treleani
Daniele Treleani
Double parton scattering, diffraction and effective cross section
17 pages, no figures
Phys.Rev.D76:076006,2007
10.1103/PhysRevD.76.076006
null
hep-ph
null
The rates of multiparton collisions in high energy hadronic interactions provide information on the typical transverse distances between partons in the hadron structure. The different configurations of the hadron in transverse space are, on the other hand, at the origin of hadron diffraction. The relation between the two phenomena is exploted in an eikonal model of hadronic interactions.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 14:04:06 GMT" } ]
2008-11-26T00:00:00
[ [ "Treleani", "Daniele", "" ] ]
0708.2604
Himansu Sahoo
H. Sahoo, T.E. Browder, K. Trabelsi, et al (for the Belle Collaboration)
Measurements of time-dependent CP violation in B^0 -> psi(2S) K_S decays
6 pages, 4 figures, presented at 2007 Lepton-Photon Symposium (BELLE-CONF-0770). Modified version published in PRD(RC)
Phys.Rev.D77:091103,2008
10.1103/PhysRevD.77.091103
Belle Preprint 2008-3, KEK Preprint 2007-72
hep-ex
null
We report improved measurements of time-dependent CP violation parameters for B^0(\bar{B}^0) -> psi(2S) K_S. This analysis is based on a data sample of 657x10^6 BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. We fully reconstruct one neutral B meson in the psi(2S) K_S CP-eigenstate decay channel, and the flavor of the accompanying B meson is identified to be either B^0 or \bar{B}^0 from its decay products. CP violation parameters are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays: S (psi(2S) K_S) = +0.72 +/- 0.09(stat) +/- 0.03(syst), A (psi(2S) K_S) = +0.04 +/- 0.07(stat) +/- 0.05(syst). These results are in agreement with results from measurements of B^0 -> J/psi K^0.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:39:11 GMT" }, { "version": "v2", "created": "Mon, 4 Feb 2008 21:25:55 GMT" }, { "version": "v3", "created": "Mon, 17 Mar 2008 23:45:33 GMT" }, { "version": "v4", "created": "Tue, 27 May 2008 07:34:38 GMT" } ]
2019-08-13T00:00:00
[ [ "Sahoo", "H.", "" ], [ "Browder", "T. E.", "" ], [ "Trabelsi", "K.", "" ] ]
0708.2605
Joanna Holt
J. Holt, C. N. Tadhunter, R. M. Gonzalez Delgado, K. J. Inskip, J. Rodriguez, B. H. C. Emonts, R. Morganti, K. A. Wills
The properties of the young stellar populations in powerful radio galaxies at low and intermediate redshifts
33 pages, 10 figures, accepted for publication in MNRAS, some low resolution figures
null
10.1111/j.1365-2966.2007.12140.x
null
astro-ph
null
Abridged. We present high-quality optical spectra for 12 powerful radio sources at low and intermediate redshifts (z < 0.7) that show evidence for a substantial UV excess. These data were taken using the WHT and VLT to determine the detailed properties of the young stellar populations (YSPs) in the host galaxies as part of a larger project to investigate evolutionary scenarios for the AGN host galaxies. The results of our spectral synthesis model fits to the spectra highlight the importance of taking into account AGN-related components (emission lines, nebular continuum, scattered light) and reddening of the stellar populations in studies of this type. It is also clear that careful examination of the fits to the spectra, as well consideration of auxilary polarimetric and imaging data, are required to avoid degeneracies in the model solutions. In 3/12 sources in our sample we find broad permitted line components, and a combination of AGN-related continuum components and an old (12.5 Gyr) stellar population provides an adequate fit to the data. In the remaining 9 sources we find strong evidence for YSPs. In contrast to some recent studies that suggest relatively old post-starburst ages for the YSPs in radio galaxies (0.3-2.5 Gyr), we deduce a wide range of ages for the YSPs in our sample objects (0.02-1.5 Gyr), with ~50% of the sample showing evidence for young YSP ages (<~0.1 Gyr) in their nuclear regions. The nuclear YSPs are often significantly reddened (0.2 < E(B-V) < 1.4) and make up a substantial fraction (~1-35%) of the total stellar mass in the regions sampled by the spectroscopic slits. Moreover, in all the cases in which we have sufficient spatial resolution we find that the UV excess is extended across the full measureable extent of the galaxy (typically 5-30 kpc), suggesting galaxy-wide starbursts.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:44:10 GMT" } ]
2009-11-13T00:00:00
[ [ "Holt", "J.", "" ], [ "Tadhunter", "C. N.", "" ], [ "Delgado", "R. M. Gonzalez", "" ], [ "Inskip", "K. J.", "" ], [ "Rodriguez", "J.", "" ], [ "Emonts", "B. H. C.", "" ], [ "Morganti", "R.", "" ], [ "Wills", "K. A.", "" ] ]
0708.2606
Xinping Xu
Xinping Xu, Junhui Hu, Feng Liu and Lianshou Liu
Scaling and correlations in three bus-transport networks of China
9 pages, 6 figures and 2 tables. Slight difference from the published one
Physica A 374(2007)441
10.1016/j.physa.2006.06.021
null
physics.soc-ph
null
We report the statistical properties of three bus-transport networks (BTN) in three different cities of China. These networks are composed of a set of bus lines and stations serviced by these. Network properties, including the degree distribution, clustering and average path length are studied in different definitions of network topology. We explore scaling laws and correlations that may govern intrinsic features of such networks. Besides, we create a weighted network representation for BTN with lines mapped to nodes and number of common stations to weights between lines. In such a representation, the distributions of degree, strength and weight are investigated. A linear behavior between strength and degree s(k) ~ k is also observed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:44:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Xu", "Xinping", "" ], [ "Hu", "Junhui", "" ], [ "Liu", "Feng", "" ], [ "Liu", "Lianshou", "" ] ]
0708.2607
Wilfried Domainko
W. Domainko (1), J. A. Hinton (2), E. C. D. Pope (2) ((1) Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany, (2) School of Physics & Astronomy University of Leeds, UK)
Gamma-ray emission associated with the Cluster-scale AGN Outbursts in the Hydra A system
Contribution to the 30th ICRC, Merida Mexico, July 2007, 4 pages, 2 figures
null
null
null
astro-ph
null
Recent observations have revealed the existence of an enormously energetic > 10^61 erg AGN outburst in the Hydra A cluster of galaxies. This outburst has produced cavities in the intra-cluster medium, apparently supported by pressure from cosmic rays. Here we argue that if these cavities are filled with > GeV particles, these particles are very likely protons and nuclei. For a plausible spatial distribution of the target gas, based on observations and hydrodynamical simulations, we show that the pi^0-decay gamma-rays from these cosmic-rays may be detectable with the H.E.S.S.experiment.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:55:53 GMT" } ]
2007-08-21T00:00:00
[ [ "Domainko", "W.", "" ], [ "Hinton", "J. A.", "" ], [ "Pope", "E. C. D.", "" ] ]
0708.2608
Xinping Xu
Xinping Xu, Junhui Hu and Feng Liu
Empirical analysis of the ship-transport network of China
20 pages, 7 figures, 1 table
Chaos 17(2007)023129
10.1063/1.2740564
null
physics.soc-ph
null
Structural properties of the ship-transport network of China (STNC) are studied in the light of recent investigations of complex networks. STNC is composed of a set of routes and ports located along the sea or river. Network properties including the degree distribution, degree correlations, clustering, shortest path length, centrality and betweenness are studied in different definition of network topology. It is found that geographical constraint plays an important role in the network topology of STNC. We also study the traffic flow of STNC based on the weighted network representation, and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology. Other features related to STNC are also investigated.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 08:57:19 GMT" } ]
2009-11-13T00:00:00
[ [ "Xu", "Xinping", "" ], [ "Hu", "Junhui", "" ], [ "Liu", "Feng", "" ] ]
0708.2609
Qiuping A. Wang
Qiuping A. Wang (ISMANS), L. Nivanen (ISMANS), A. El Kaabouchi (ISMANS), J.P. Badiali (ISMANS), A. Le M\'ehaut\'e (ISMANS)
Incomplete normalization of probability on multifractals
10 pages, to appear in Physica A (2007)
Physica A 386, 1 (2007) 92-100
10.1016/j.physa.2007.08.009
null
cond-mat.stat-mech
null
This work is an extension of the incomplete probability theory from the simple case of monofractals previously studied to the more general case of multifractals which can occur in the phase space without equiprobable partition.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:02:14 GMT" } ]
2007-11-13T00:00:00
[ [ "Wang", "Qiuping A.", "", "ISMANS" ], [ "Nivanen", "L.", "", "ISMANS" ], [ "Kaabouchi", "A. El", "", "ISMANS" ], [ "Badiali", "J. P.", "", "ISMANS" ], [ "Méhauté", "A. Le", "", "ISMANS" ] ]
0708.2610
Xinping Xu
Xinping Xu
Connection probability for random graphs with given degree sequence
5 papes, no figure
null
null
null
math-ph math.MP
null
Recently, the classical configuration model for random graphs with given degree distribution has been extensively used as a null model in contraposition to real networks with the same degree distribution. In this paper, we briefly review the applications of this model and derive analytical expression for connection probability by the expanding coefficient method. We also use our expanding coefficient method to obtain the connection probability for the directed configuration model.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:03:52 GMT" } ]
2007-08-21T00:00:00
[ [ "Xu", "Xinping", "" ] ]
0708.2611
Dieudonne Agbor Agbor Mr
Dieudonne Agbor
Boundedness and Compactness of Toeplitz operators with L^1 symbols on the Bergman space
This paper has been withdrawn
null
null
null
math.CV math.CA
null
We characterise the boundedness of a Toeplitz operator on the Bergman space with an L^1 symbol.We also prove that the compactness of a Toeplitz operator on the Bergman space with an L^1 symbol is completely determined by the boundary behaviour of itss Berezin transform. This result extends known results in the cases when the symbol is either a positive L^1 function, an L^\infty function or a general BMO^1 function.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:05:33 GMT" }, { "version": "v2", "created": "Tue, 13 Nov 2012 20:36:56 GMT" } ]
2012-11-14T00:00:00
[ [ "Agbor", "Dieudonne", "" ] ]
0708.2612
Matthew Coleman
Matthew G. Coleman and Jelte de Jong (Max-Planck-Institut fur Astronomie)
First Results From the Large Binocular Telescope: Deep Photometry of New dSphs
Four pages, two figures. To appear in the proceedings of "Galaxies in the Local Volume", Astrophysics and Space Science, editors B. Koribalski and H. Jerjen
null
10.1007/978-1-4020-6933-8_45
null
astro-ph
null
This contribution describes photometry for two Galactic dSphs obtained with the Large Binocular Telescope to a magnitude of ~25.5. Using the Large Binocular Camera, a purpose-built wide-field imager for the LBT, we have examined the structure and star formation histories of two newly-discovered Local Group members, the Hercules dSph and the Leo T dSph/dIrr system. We have constructed a structural map for the Hercules system using three-filter photometry to V ~ 25.5. This is the first deep photometry for this system, and it indicates that Hercules is unusually elongated, possibly indicating distortion due to the Galactic tidal field. We have also derived the first star formation history for the Leo T system, and find that its oldest population of stars (age ~ 13 Gyr) were relatively metal-rich, with [Fe/H] ~ -1.5.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:17:34 GMT" } ]
2015-05-13T00:00:00
[ [ "Coleman", "Matthew G.", "", "Max-Planck-Institut fur\n Astronomie" ], [ "de Jong", "Jelte", "", "Max-Planck-Institut fur\n Astronomie" ] ]
0708.2613
Qingfeng Li
Qingfeng Li
Pion freeze-out through HBT correlation in HICs from AGS/FAIR to RHIC energies
10 pages, 6 figs. For PoS CPOD2007, July 9-13, GSI,Germany
PoSCPOD07:048,2007
null
null
nucl-th
null
In this talk we present the results of two-pion HBT correlation at freeze-out in heavy ion collisions (HICs) from AGS to RHIC energies. The UrQMD hadron-string transport model as well as the CRAB analyzing program are adopted. Based on the cascade mode, in general, the calculations are satisfying and well in line with the experimental data although discrepancies are not negligible. Such as: I), the HBT time-related puzzle exists at all energies. II), at low AGS energies, the calculated volume as well as the mean free path of pion source at freeze-out are lower than data. It implies that a better description of interactions of particles at early stage of HICs is required.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:12:24 GMT" } ]
2008-11-26T00:00:00
[ [ "Li", "Qingfeng", "" ] ]
0708.2614
Changxing Miao
Changxing Miao, Guixiang Xu and Lifeng Zhao
On the blow up phenomenon for the $L^2$-critical focusing Hartree equation in $\Bbb R^4$
25pages
Colloquium Mathematicum, 119(2010)23-50
10.4064/cm119-1-2
null
math.AP math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We characterize the dynamics of the finite time blow up solutions with minimal mass for the focusing mass critical Hartree equation with $H^1(\mathbb{R}^4)$ data and $L^2(\mathbb{R}^4)$ data, where we make use of the refined Gagliardo-Nirenberg inequality of convolution type and the profile decomposition. Moreover, we also analyze the mass concentration phenomenon of such blow up solutions.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:17:57 GMT" }, { "version": "v2", "created": "Fri, 28 Dec 2007 12:08:54 GMT" }, { "version": "v3", "created": "Wed, 14 May 2008 08:48:07 GMT" }, { "version": "v4", "created": "Wed, 27 Aug 2008 01:32:04 GMT" } ]
2010-03-24T00:00:00
[ [ "Miao", "Changxing", "" ], [ "Xu", "Guixiang", "" ], [ "Zhao", "Lifeng", "" ] ]
0708.2615
Sebastian Bustingorry
Sebastian Bustingorry
Aging dynamics of non-linear elastic interfaces: the Kardar-Parisi-Zhang equation
14 pages, 6 figures
J. Stat. Mech (2007) P10002
10.1088/1742-5468/2007/10/P10002
null
cond-mat.stat-mech
null
In this work, the out-of-equilibrium dynamics of the Kardar-Parisi-Zhang equation in (1+1) dimensions is studied by means of numerical simulations, focussing on the two-times evolution of an interface in the absence of any disordered environment. This work shows that even in this simple case, a rich aging behavior develops. A multiplicative aging scenario for the two-times roughness of the system is observed, characterized by the same growth exponent as in the stationary regime. The analysis permits the identification of the relevant growing correlation length, accounting for the important scaling variables in the system. The distribution function of the two-times roughness is also computed and described in terms of a generalized scaling relation. These results give good insight into the glassy dynamics of the important case of a non-linear elastic line in a disordered medium.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:26:41 GMT" } ]
2009-11-13T00:00:00
[ [ "Bustingorry", "Sebastian", "" ] ]
0708.2616
Sourav Dhar
Sourav Dhar and Kabir Chakraborty
An Experimental Investigation of Secure Communication With Chaos Masking
8 pages, 7 figures
null
null
null
cs.CR
null
The most exciting recent development in nonlinear dynamics is realization that chaos can be useful. One application involves "Secure Communication". Two piecewise linear systems with switching nonlinearities have been taken as chaos generators. In the present work the phenomenon of secure communication with chaos masking has been investigated experimentally. In this investigation chaos which is generated from two chaos generators is masked with the massage signal to be transmitted, thus makes communication is more secure.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:39:18 GMT" } ]
2007-08-21T00:00:00
[ [ "Dhar", "Sourav", "" ], [ "Chakraborty", "Kabir", "" ] ]
0708.2617
Ana M. Teixeira
A.M. Teixeira, S. Antusch, E. Arganda, M.J. Herrero
Sensitivity to SUSY Seesaw Parameters and Lepton Flavour Violation
6 pages, 4 figures. Presented at 5th Flavor Physics and CP Violation Conference (FPCP 2007), Bled, Slovenia, 12-16 May 2007
ECONFC070512:029,2007
null
null
hep-ph
null
We address the constraints on the SUSY seesaw parameters arising from Lepton Flavour Violation observables. Working in the Constrained Minimal Supersymmetric Standard Model extended by three right-handed (s)neutrinos, we study the predictions for the branching ratios of $l_j \to l_i \gamma$ and $l_j \to 3 l_i$ channels. We impose compatibility with neutrino data, electric dipole moment bounds, and further require a successful baryon asymmetry of the Universe (via thermal leptogenesis). We emphasise the interesting interplay between $\theta_{13}$ and the LFV muon decays, pointing out the hints on the SUSY seesaw parameters that can arise from measurements of $\theta_{13}$ and LFV branching ratios. This is a brief summary of the work of Ref. \cite{Antusch:2006vw}.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:39:40 GMT" } ]
2008-11-26T00:00:00
[ [ "Teixeira", "A. M.", "" ], [ "Antusch", "S.", "" ], [ "Arganda", "E.", "" ], [ "Herrero", "M. J.", "" ] ]
0708.2618
Guilhem Lavaux
G. Lavaux (1), R. Mohayaee (1), S. Colombi (1) and R. B. Tully (2) ((1) IAP / Univ. Paris 6, (2) IfA, Univ. of Hawaii)
Using Local Volume data to constrain Dark Matter dynamics
4 pages, 2 figures. To be published in the proceedings of ``Galaxies in the Local Volume'', Sydney 8 to 13 July 2007
null
10.1007/978-1-4020-6933-8_6
null
astro-ph
null
The peculiar velocity reconstruction methods allow one to have a deeper insight into the distribution of dark matter: both to measure mean matter density and to obtain the primordial density fluctuations. We present here the Monge-Ampere-Kantorovitch method applied to mock catalogues mimicking in both redshift and distance catalogues. After having discussed the results obtained for a class of biases that may be corrected for, we focus on the systematics coming from the unknown distribution of unobserved mass and from the statistical relationship between mass and luminosity. We then show how to use these systematics to put constraints on the dark matter distribution. Finally a preliminary application to an extended version (c z < 3000 km/s) of the Neighbour Galaxy Catalogue is presented. We recover the peculiar velocities in our neighbourhood and present a preliminary measurement of the local Omega_M.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:53:15 GMT" } ]
2015-05-13T00:00:00
[ [ "Lavaux", "G.", "", "IAP / Univ. Paris 6" ], [ "Mohayaee", "R.", "", "IAP / Univ. Paris 6" ], [ "Colombi", "S.", "", "IAP / Univ. Paris 6" ], [ "Tully", "R. B.", "", "IfA, Univ. of Hawaii" ] ]
0708.2619
Kaustubh Priolkar
P. A. Bhobe, K. R. Priolkar, P. R. Sarode
Factors influencing the Martensitic interactions in Ni50Mn35Sn15: An EXAFS study
20 pages, 9 figures
null
10.1088/0953-8984/20/01/015219
null
cond-mat.mtrl-sci
null
Extended x-ray absorption fine-structure (EXAFS) measurements have been carried out on Ni$_{50}$Mn$_{35}$Sn$_{15}$ in the austenitic and martensitic phase. The temperatures associated with structural and magnetic phase transformations are obtained from magnetization measurements. The system orders ferromagnetically below 319 K while the structural phase transition occurs at T$_M$ $\sim$ 200 K. EXAFS measurements have been carried out at Mn and Ni K-edges and changes associated with respect to the local structure of these absorbing atoms are compared. Significant changes in the nearest neighbour interactions are seen as the system transits to the low temperature martensitic phase. EXAFS provides evidence for local structural distortion even in the cubic phase that is not seen from the x-ray diffraction studies. The results obtained are understood in terms of changing hybridization between the constituent atoms that influence the electronic structure at the Fermi level, associated with the austenitic-to-martensitic transition.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 09:56:19 GMT" } ]
2009-11-13T00:00:00
[ [ "Bhobe", "P. A.", "" ], [ "Priolkar", "K. R.", "" ], [ "Sarode", "P. R.", "" ] ]
0708.2620
Shenshen Wang
Shenshen Wang and Tai-Kai Ng
On the (circular) polarization-independence of microwave-induced resistance oscillations and zero resistance state
4 two-column pages, 2 figures, 1 table
Phys. Rev. B 77, 165324 (2008)
10.1103/PhysRevB.77.165324
null
cond-mat.mes-hall cond-mat.other
null
The immunity of microwave-induced magneto-resistance oscillations and corresponding zero resistance regions to the direction of (circular) polarization of microwave is studied in this paper. We propose that a spontaneous circular motion of the whole electron fluid would stabilize the system and minimize the polarization sensitivity of the oscillatory DC resistance. Results of a self-consistent calculation capture the qualitative features of the experimental observation.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:05:58 GMT" } ]
2012-06-01T00:00:00
[ [ "Wang", "Shenshen", "" ], [ "Ng", "Tai-Kai", "" ] ]
0708.2621
Claude Amsler
C. Amsler, V. Boccone, A. Buchler, R. Chandrasekharan, C. Regenfus, J. Rochet
Luminescence quenching of the triplet excimer state by air traces in gaseous argon
7 pages submitted to NIM A
JINST 3:P02001,2008
10.1088/1748-0221/3/02/P02001
null
physics.ins-det physics.atm-clus
null
While developing a liquid argon detector for dark matter searches we investigate the influence of air contamination on the VUV scintillation yield in gaseous argon at atmospheric pressure. We determine with a radioactive alpha-source the photon yield for various partial air pressures and different reflectors and wavelength shifters. We find for the fast scintillation component a time constant tau1= 11.3 +- 2.8 ns, independent of gas purity. However, the decay time of the slow component depends on gas purity and is a good indicator for the total VUV light yield. This dependence is attributed to impurities destroying the long-lived argon excimer states. The population ratio between the slowly and the fast decaying excimer states is determined for alpha-particles to be 5.5 +-0.6 in argon gas at 1100 mbar and room temperature. The measured mean life of the slow component is tau2 = 3.140 +- 0.067 microsec at a partial air pressure of 2 x 10-6 mbar.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:17:03 GMT" } ]
2010-01-28T00:00:00
[ [ "Amsler", "C.", "" ], [ "Boccone", "V.", "" ], [ "Buchler", "A.", "" ], [ "Chandrasekharan", "R.", "" ], [ "Regenfus", "C.", "" ], [ "Rochet", "J.", "" ] ]
0708.2622
Sonja Hillert
S. Hillert (for the LCFI Collaboration)
The LCFIVertex Package: vertex detector-based Reconstruction at the ILC
Proceedings of the 2007 International Linear Collider Workshop, DESY, 29 May - 4 June 2007, 6 pages, 4 figures
ECONF C0705302:SIM25,2007
null
null
physics.ins-det physics.data-an
null
The contribution gives an overview of the LCFIVertex package, providing software tools for high-level event reconstruction at the International Linear Collider using vertex-detector information. The package was validated using a fast Monte Carlo simulation. Performance obtained with a more realistic GEANT4-based detector simulation and realistic tracking code is presented. The influence of hadronic interactions on flavour tagging is discussed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:24:13 GMT" } ]
2019-08-13T00:00:00
[ [ "Hillert", "S.", "", "for the LCFI Collaboration" ] ]
0708.2623
Hailu Luo
Hailu Luo, Zhongzhou Ren, Weixing Shu, Shuangchun Wen
Reversed propagation dynamics of Laguerre-Gaussian beams in left-handed materials
7 pages, 4 figures
Physical Review A 77, 023812 (2008)
10.1103/PhysRevA.77.023812
null
physics.optics
null
On the basis of angular spectrum representation, the reversed propagation dynamics of Laguerre-Gaussian beam in left-handed materials (LHMs) is presented. We show that negative phase velocity gives rise to a reversed screw of wave-front, and ultimately leads to a reversed rotation of optical vortex. Furthermore, negative Gouy-phase shift causes an inverse spiral of Poynting vector. It is found that the Laguerre-Gaussian beam in LHMs will present the same propagation characteristics as the counterpart with opposite topological charges in regular right-handed materials (RHMs). The momentum conservation theorem insures that the tangential component of the wave momentum at the RHM-LHM boundary is conserved. It is shown that although the linear momentum reverses its direction, the angular momentum remains unchanged.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:27:38 GMT" }, { "version": "v2", "created": "Wed, 20 Feb 2008 04:28:02 GMT" } ]
2009-11-13T00:00:00
[ [ "Luo", "Hailu", "" ], [ "Ren", "Zhongzhou", "" ], [ "Shu", "Weixing", "" ], [ "Wen", "Shuangchun", "" ] ]
0708.2624
Edward Goldobin
E. Goldobin, D. Koelle, R. Kleiner, A. Buzdin
Josephson junctions with negative second harmonic in the current-phase relation: properties of novel varphi-junctions
submitted to PRB
Phys. Rev. B 76, 224523 (2007)
10.1103/PhysRevB.76.224523
null
cond-mat.supr-con
null
Several recent experiments revealed a change of the sign of the first harmonic in the current-phase relation of Josephson junctions (JJ) based on novel superconductors, e.g., d-wave based or JJ with ferromagnetic barrier. In this situation the role of the second harmonic becomes dominant and it determines the scenario of a 0-pi transition. We discuss different mechanisms of the second harmonic generation and its sign. If the second harmonic is negative the 0-pi transition becomes continuous and the realization of the so-called varphi junction is possible. We study the unusual properties of such a novel JJ and analyze the possible experimental techniques for their observation.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:54:57 GMT" } ]
2007-12-24T00:00:00
[ [ "Goldobin", "E.", "" ], [ "Koelle", "D.", "" ], [ "Kleiner", "R.", "" ], [ "Buzdin", "A.", "" ] ]
0708.2625
Mais Suleymanov
Y. H. Huseynaliyev, M. K. Suleymanov, E. U. Khan, A. Kravchakova, S. Vokal
Search for a signal on intermediate baryon systems formation in hadron-nuclear and nuclear-nuclear interactions at high energies
2 pages and one figure
J.Phys.Conf.Ser.110:122007,2008
10.1088/1742-6596/110/12/122007
null
nucl-ex
null
We have analyzed the behavior of different characteristics of hadron-nuclear and nuclear-nuclear interactions as a function of centrality to get a signal on the formation of intermediate baryon systems. We observed that the data demonstrate the regime change and saturation. The angular distributions of slow particles exhibit some structure in the above mentioned reactions at low energy. We believe that the structure could be connected with the formation and decay of the percolation cluster. With increasing the mass of colliding nuclei, the structure starts to become weak and almost disappears ultimately. This shows that the number of secondary internuclear interactions increases with increasing the mass of the colliding nuclei. The latter could be a reason of the disintegration of any intermediate formations as well as clusters, which decrease their influence on the angular distribution of the emitted particles.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:34:23 GMT" } ]
2008-11-26T00:00:00
[ [ "Huseynaliyev", "Y. H.", "" ], [ "Suleymanov", "M. K.", "" ], [ "Khan", "E. U.", "" ], [ "Kravchakova", "A.", "" ], [ "Vokal", "S.", "" ] ]
0708.2626
Simeon Pol'shin
S. A. Pol'shin
A cohomological construction of modules over Fedosov deformation quantization algebra
8 pages, latex. Final version to appear in IJGMMP
Int. J. Geom. Meth. Mod. Phys. 5 (2008) 547 - 556
10.1142/S021988780800293X
null
math.QA math-ph math.MP
null
In certain neighborhood $U$ of an arbitrary point of a symplectic manifold $M$ we construct a Fedosov-type star-product $\ast_L$ such that for an arbitrary leaf $\wp$ of a given polarization $\mathcal{D}\subset TM$ the algebra $C^\infty (\wp \cap U)[[h]]$ has a natural structure of left module over the deformed algebra $(C^\infty (U)[[h]], \ast_L)$. With certain additional assumptions on $M$, $\ast_L$ becomes a so-called star-product with separation of variables.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:39:04 GMT" }, { "version": "v2", "created": "Mon, 24 Sep 2007 00:02:01 GMT" }, { "version": "v3", "created": "Thu, 27 Dec 2007 11:47:16 GMT" }, { "version": "v4", "created": "Thu, 3 Apr 2008 22:18:02 GMT" } ]
2015-05-13T00:00:00
[ [ "Pol'shin", "S. A.", "" ] ]
0708.2627
Giulio Bonelli
Giulio Bonelli and Alessandro Tanzini
The holomorphic anomaly for open string moduli
1+14 pages, 6 figures! v2: ref. added v3: section 4 expanded, 1+17 pages, 11 figures!!, to be publ. in JHEP
JHEP 0710:060,2007
10.1088/1126-6708/2007/10/060
SISSA 55/2007/EP
hep-th math.AG
null
We complete the holomorphic anomaly equations for topological strings with their dependence on open moduli. We obtain the complete system by standard path integral arguments generalizing the analysis of BCOV (Commun. Math. Phys. 165 (1994) 311) to strings with boundaries. We study both the anti-holomorphic dependence on open moduli and on closed moduli in presence of Wilson lines. By providing the compactification a' la Deligne-Mumford of the moduli space of Riemann surfaces with boundaries, we show that the open holomorphic anomaly equations are structured on the (real codimension one) boundary components of this space.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:42:10 GMT" }, { "version": "v2", "created": "Thu, 30 Aug 2007 15:27:02 GMT" }, { "version": "v3", "created": "Fri, 12 Oct 2007 12:41:23 GMT" } ]
2009-06-11T00:00:00
[ [ "Bonelli", "Giulio", "" ], [ "Tanzini", "Alessandro", "" ] ]
0708.2628
Alexander Felshtyn
Alexander Fel'shtyn and Daciberg L. Gon\c{c}alves
Twisted conjugacy classes in Symplectic groups, Mapping class groups and Braid groups(including an Appendix written with Francois Dahmani)
21 pages, with Appendix
null
null
null
math.GR math.GT
null
We prove that the symplectic group $Sp(2n,\mathbb Z)$ and the mapping class group $Mod_{S}$ of a compact surface $S$ satisfy the $R_{\infty}$ property. We also show that $B_n(S)$, the full braid group on $n$-strings of a surface $S$, satisfies the $R_{\infty}$ property in the cases where $S$ is either the compact disk $D$, or the sphere $S^2$. This means that for any automorphism $\phi$ of $G$, where $G$ is one of the above groups, the number of twisted $\phi$-conjugacy classes is infinite.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:42:21 GMT" }, { "version": "v2", "created": "Sun, 16 Dec 2007 21:49:55 GMT" } ]
2007-12-16T00:00:00
[ [ "Fel'shtyn", "Alexander", "" ], [ "Gonçalves", "Daciberg L.", "" ] ]
0708.2629
Mauro Sbragaglia Dr
C. Pirat, M. Sbragaglia, A. M. Peters, B. M. Borkent, R. G. H. Lammertink, M. Wessling and D. Lohse
Dynamics of the spontaneous breakdown of superhydrophobicity
7 pages, 5 figures
Europhysics Letters 81, 66002 (2008)
10.1209/0295-5075/81/66002
null
physics.flu-dyn cond-mat.dis-nn nlin.PS
null
Drops deposited on rough and hydrophobic surfaces can stay suspended with gas pockets underneath the liquid, then showing very low hydrodynamic resistance. When this superhydrophobic state breaks down, the subsequent wetting process can show different dynamical properties. A suitable choice of the geometry can make the wetting front propagate in a stepwise manner leading to {\it square-shaped} wetted area: the front propagation is slow and the patterned surface fills by rows through a {\it zipping} mechanism. The multiple time scale scenario of this wetting process is experimentally characterized and compared to numerical simulations.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 10:45:10 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 09:05:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Pirat", "C.", "" ], [ "Sbragaglia", "M.", "" ], [ "Peters", "A. M.", "" ], [ "Borkent", "B. M.", "" ], [ "Lammertink", "R. G. H.", "" ], [ "Wessling", "M.", "" ], [ "Lohse", "D.", "" ] ]
0708.2630
Terry C. Awes
WA98 Collaboration: M. M. Aggarwal, et al
Suppression of High-p_T Neutral Pion Production in Central Pb+Pb Collisions at sqrt{s_NN} = 17.3 GeV Relative to p+C and p+Pb Collisions
5 pages, 4 figures
Phys.Rev.Lett.100:242301,2008
10.1103/PhysRevLett.100.242301
null
nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt{s_NN} = 17.4 GeV at mid-rapidity 2.3 < eta_lab < 3.0 over the range 0.7< p_T < 3.5 GeV/c. The spectra are compared to pi0 spectra measured in Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N_part < 300) the yield of pi0's with p_T > 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N_coll), while for central Pb+Pb collisions with N_part > 350 the pi0 yield is suppressed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 19:58:36 GMT" }, { "version": "v2", "created": "Tue, 17 Jun 2008 01:42:21 GMT" } ]
2008-11-26T00:00:00
[ [ "WA98 Collaboration", "", "" ], [ "Aggarwal", "M. M.", "" ] ]
0708.2631
Taysun Kimm
Taysun Kimm and Sukyoung K. Yi
Intrinsic Axis Ratio Distribution of Early-type Galaxies From Sloan Digital Sky Survey
9 pages, 11 figures, Accepted for publication in ApJ
null
10.1086/522573
null
astro-ph
null
Using Sloan Digital Sky Survey Data Release 5, we have investigated the intrinsic axis ratio distribution (ARD) for early-type galaxies. We have constructed a volume-limited sample of 3,922 visually-inspected early-type galaxies at $0.05 \leq z \leq 0.06$ carefully considering sampling biases caused by the galaxy isophotal size and luminosity. We attempt to de-project the observed ARD into three-dimensional types (oblate, prolate, and triaxial), which are classified in terms of triaxiality. We confirm that no linear combination of $randomly$-distributed axis ratios of the three types can reproduce the observed ARD. However, using Gaussian intrinsic distributions, we have found reasonable fits to the data with preferred mean axis ratios for oblate, prolate, and triaxial (triaxials in two axis ratios), $\mu_o=0.44, \mu_p=0.72, \mu_{t,\beta}=0.92, \mu_{t,\gamma}=0.78$ where the fractions of oblate, prolate and triaxial types are \textrm{O:P:T}=0.29^{\pm0.09}:0.26^{\pm0.11}:0.45^{\pm0.13}$. We have also found that the luminous sample ($-23.3 < M_r \leq -21.2$) tends to have more triaxials than the less luminous ($-21.2 < M_r <-19.3$) sample does. Oblate is relatively more abundant among the less luminous galaxies. Interestingly, the preferences of axis ratios for triaxial types in the two luminosity classes are remarkably similar. We have not found any significant influence of the local galaxy number density on ARD. We show that the results can be seriously affected by the details in the data selection and type classification scheme. Caveats and implications on galaxy formation are discussed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:05:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Kimm", "Taysun", "" ], [ "Yi", "Sukyoung K.", "" ] ]
0708.2632
Olga Holtz
Olga Holtz, Amos Ron
Zonotopal algebra
44 pages; updated to reflect referees' remarks and the developments in the area since the article first appeared on the arXiv
Advances in Mathematics, 227 (2011), no.2, 847-894
10.1016/j.aim.2011.02.012
null
math.AC math.CA math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A wealth of geometric and combinatorial properties of a given linear endomorphism $X$ of $\R^N$ is captured in the study of its associated zonotope $Z(X)$, and, by duality, its associated hyperplane arrangement ${\cal H}(X)$. This well-known line of study is particularly interesting in case $n\eqbd\rank X \ll N$. We enhance this study to an algebraic level, and associate $X$ with three algebraic structures, referred herein as {\it external, central, and internal.} Each algebraic structure is given in terms of a pair of homogeneous polynomial ideals in $n$ variables that are dual to each other: one encodes properties of the arrangement ${\cal H}(X)$, while the other encodes by duality properties of the zonotope $Z(X)$. The algebraic structures are defined purely in terms of the combinatorial structure of $X$, but are subsequently proved to be equally obtainable by applying suitable algebro-analytic operations to either of $Z(X)$ or ${\cal H}(X)$. The theory is universal in the sense that it requires no assumptions on the map $X$ (the only exception being that the algebro-analytic operations on $Z(X)$ yield sought-for results only in case $X$ is unimodular), and provides new tools that can be used in enumerative combinatorics, graph theory, representation theory, polytope geometry, and approximation theory.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 19:24:49 GMT" }, { "version": "v2", "created": "Sat, 26 Jan 2008 16:20:31 GMT" }, { "version": "v3", "created": "Wed, 9 Mar 2011 19:49:57 GMT" } ]
2011-04-11T00:00:00
[ [ "Holtz", "Olga", "" ], [ "Ron", "Amos", "" ] ]
0708.2633
Jean-Luc Lehners
Jean-Luc Lehners
Bouncing and Colliding Branes
4 pages. Contribution to the proceedings of PASCOS-07, 2-7 July 2007, Imperial College, London
AIP Conf.Proc.957:337-340,2007
10.1063/1.2823796
null
hep-th
null
In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of negative-tension domain walls to bounce off spacetime singularities and the consequences for cosmological perturbations. In this context, we will also review a colliding branes solution of heterotic M-theory that has been proposed as a model for early universe cosmology.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:12:21 GMT" } ]
2011-03-10T00:00:00
[ [ "Lehners", "Jean-Luc", "" ] ]
0708.2634
Sergey Sevbitov
S. N. Sevbitov and T. V. Shishkina
Bremsstrahlung in weak charged current polarized lepton-nucleon deep inelastic scattering
8 pages, 2 figures, talk given at Int. school-seminar NPQCD-2007
null
null
null
hep-ph
null
The processes of lepton-nucleon scattering, including ones with both polarized beams, at high energy provide relevant information about interaction and particles structure, allowing to analyze nucleon spin structure. As energy and experimental accuracy rise, necessity to improve Born cross sections and polarized asymmetries with higher order radiative corrections becomes substantial. In this report we stress on lowest order bremsstrahlung corrections treatment using helicity amplitudes method as applied to actual nowadays charged current lepton-nucleon deep inelastic processes, that allows to simplify matrix element calculation procedure. Real photon emission contribution is calculated by means of Lorentz-invariant formalism. Kinematical peculiarities on bremsstrahlung correction are discussed.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 19:13:27 GMT" } ]
2007-08-21T00:00:00
[ [ "Sevbitov", "S. N.", "" ], [ "Shishkina", "T. V.", "" ] ]
0708.2635
Dieudonne Agbor Agbor Mr
Dieudonne Agbor
Boundedness and Compactness of products of Toeplitz operators on the Bergman Space
The paper has been withdrawn
null
null
null
math.CV math.CA
null
In a celebrated conjecture D.Sarason stated a necessary and sufficient condition on the symbols f, g in the Bergman space, L^2_a(\Delta) of the unit disk, \Delta, for the products T_{f}T_{\bar g} of associated Toeplitz operators to be bounded (respectively compact) on L^2_a(\Delta) . K. Stroethoff and D. Zheng proved that these conditions are necessary. We prove the sufficiency of these conditions, thus solvind Sarason's conjecture.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:15:33 GMT" }, { "version": "v2", "created": "Tue, 13 Nov 2012 20:23:16 GMT" } ]
2012-11-14T00:00:00
[ [ "Agbor", "Dieudonne", "" ] ]
0708.2636
Shaun Stevens
Corinne Blondel, Shaun Stevens
Genericity of supercuspidal representations of p-adic Sp(4)
35 pages
null
10.1112/S0010437X08003849
null
math.RT math.NT
null
We describe the supercuspidal representations of Sp(4,F), for F a non-archimedean local field of residual characteristic different from 2, and determine which are generic.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:18:05 GMT" } ]
2014-01-14T00:00:00
[ [ "Blondel", "Corinne", "" ], [ "Stevens", "Shaun", "" ] ]
0708.2637
Leonhard Meyer
L. Meyer, R. Schoedel, A. Eckart, W. J. Duschl, V. Karas and M. Dovciak
On the orientation of the Sagittarius A* system
10 pages, 4 figures; Research Note accepted by A&A for publication
null
10.1051/0004-6361:20078009
null
astro-ph
null
The near-infrared emission from the black hole at the Galactic center (Sgr A*) has unique properties. The most striking feature is a suggestive periodic sub-structure that has been observed in a couple of flares so far. Using near-infrared polarimetric observations and modelling the quasi-periodicity in terms of an orbiting blob, we try to constrain the three dimensional orientation of the Sgr A* system. We report on so far unpublished polarimetric data from 2003. They support the observations of a roughly constant mean polarization angle of 60 degr \pm 20 degr from 2004-2006. Prior investigations of the 2006 data are deepened. In particular, the blob model fits are evaluated such that constraints on the position angle of Sgr A* can be derived. Confidence contours in the position-inclination angle plane are derived. On a 3sigma level the position angle of the equatorial plane normal is in the range 60 degr - 108 degr (east of north) in combination with a large inclination angle. This agrees well with recent independent work in which radio spectral/morphological properties of Sgr A* and X-ray observations, respectively, have been used. However, the quality of the presently available data and the uncertainties in our model bring some ambiguity to our conclusions.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:19:39 GMT" } ]
2009-11-13T00:00:00
[ [ "Meyer", "L.", "" ], [ "Schoedel", "R.", "" ], [ "Eckart", "A.", "" ], [ "Duschl", "W. J.", "" ], [ "Karas", "V.", "" ], [ "Dovciak", "M.", "" ] ]
0708.2638
Christopher Hemming
Christopher J. Hemming, Roman V. Krems
Three-State Feshbach Resonances Mediated By Second-Order Couplings
27 pages, 4 figures; added a reference; journal reference/DOI refer to final published version, which is a shortened and modified version of this preprint
Phys. Rev. A 77, 022705 (2008)
10.1103/PhysRevA.77.022705
null
physics.atom-ph physics.chem-ph
null
We present an analytical study of three-state Feshbach resonances induced by second-order couplings. Such resonances arise when the scattering amplitude is modified by the interaction with a bound state that is not directly coupled to the scattering state containing incoming flux. Coupling occurs indirectly through an intermediate state. We consider two problems: (i) the intermediate state is a scattering state in a distinct open channel; (ii) the intermediate state is an off-resonant bound state in a distinct closed channel. The first problem is a model of electric-field-induced resonances in ultracold collisions of alkali metal atoms [Phys. Rev. A 75, 032709 (2007)] and the second problem is relevant for ultracold collisions of complex polyatomic molecules, chemical reaction dynamics, photoassociation of ultracold atoms, and electron - molecule scattering. Our analysis yields general expressions for the energy dependence of the T-matrix elements modified by three-state resonances and the dependence of the resonance positions and widths on coupling amplitudes for the weak-coupling limit. We show that the second problem can be generalized to describe resonances induced by indirect coupling through an arbitrary number of sequentially coupled off-resonant bound states and analyze the dependence of the resonance width on the number of the intermediate states.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 19:25:10 GMT" }, { "version": "v2", "created": "Thu, 21 Feb 2008 01:14:59 GMT" } ]
2008-02-21T00:00:00
[ [ "Hemming", "Christopher J.", "" ], [ "Krems", "Roman V.", "" ] ]
0708.2639
Jacob D. Bekenstein
Eva Sagi and Jacob D. Bekenstein
Black holes in the TeVeS theory of gravity and their thermodynamics
12 pages, ReVTex, version to be published in Phys. Rev. D
Phys.Rev.D77:024010,2008
10.1103/PhysRevD.77.024010
null
gr-qc astro-ph hep-th
null
TeVeS, a relativistic theory of gravity, was designed to provide a basis for the modified Newtonian dynamics. Since TeVeS differs from general relativity (e.g., it has two metrics, an Einstein metric and a physical metric), black hole solutions of it would be valuable for a number of endeavors ranging from astrophysical modeling to investigations into the interrelation between gravity and thermodynamics. Giannios has recently found a TeVeS analogue of the Schwarzschild black hole solution. We proceed further with the program by analytically solving the TeVeS equations for a static spherically symmetric and asymptotically flat system of electromagnetic and gravity fields. We show that one solution is provided by the Reissner-Nordstrom metric as physical metric, the TeVeS vector field pointing in the time direction, and a TeVeS scalar field positive everywhere (the last feature protects from superluminal propagation of disturbances in the fields). We work out black hole thermodynamics in TeVeS using the physical metric; black hole entropy, temperature and electric potential turn out to be identical to those in general relativity. We find it inconsistent to base thermodynamics on the Einstein metric. In light of this we reconsider the Dubovsky-Sibiryakov scenario for violating the second law of thermodynamics in theories with Lorentz symmetry violation.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:25:29 GMT" }, { "version": "v2", "created": "Fri, 2 Nov 2007 09:20:50 GMT" }, { "version": "v3", "created": "Wed, 9 Jan 2008 09:28:10 GMT" } ]
2008-11-26T00:00:00
[ [ "Sagi", "Eva", "" ], [ "Bekenstein", "Jacob D.", "" ] ]
0708.2640
Francis Keenan
F. P. Keenan, J. J. Drake, K. M. Aggarwal
An investigation of Fe XVI emission lines in solar and stellar EUV and soft X-ray spectra
6 pages, 4 tables, 1 figure, MNRAS in press
null
10.1111/j.1365-2966.2007.12365.x
null
astro-ph
null
New fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fe XVI are used to determine theoretical emission-line ratios applicable to the 251 - 361 A and 32 - 77 A portions of the extreme-ultraviolet (EUV) and soft X-ray spectral regions, respectively. A comparison of the EUV results with observations from the Solar Extreme-Ultraviolet Research Telescope and Spectrograph (SERTS) reveals excellent agreement between theory and experiment. However, for emission lines in the 32 - 49 A portion of the soft X-ray spectral region, there are large discrepancies between theory and measurement for both a solar flare spectrum obtained with the X-Ray Spectrometer/Spectrograph Telescope (XSST) and observations of Capella from the Low Energy Transmission Grating Spectrometer (LETGS) on the Chandra X-ray Observatory. These are probably due to blending in the solar flare and Capella data from both first order lines and from shorter wavelength transitions detected in second and third order. By contrast, there is very good agreement between our theoretical results and the XSST and LETGS observations in the 50 - 77 A wavelength range, contrary to previous results. In particular, there is no evidence that the Fe XVI emission from the XSST flare arises from plasma at a much higher temperature than that expected for Fe XVI in ionization equilibrium, as suggested by earlier work.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:27:09 GMT" } ]
2009-11-13T00:00:00
[ [ "Keenan", "F. P.", "" ], [ "Drake", "J. J.", "" ], [ "Aggarwal", "K. M.", "" ] ]
0708.2641
Teck-Ghee Lee
Teck-Ghee Lee (ORNL & Univ. Kentucky), S. Yu. Ovchinnikov (ORNL & Univ. Tennessee), J. Sternberg (Univ. Tennessee), V. Chupryna (Univ. Tennessee), D. R. Schultz (ORNL) and J. H. Macek (ORNL & Univ. Tennessee)
Quantum Treatment of Continuum Electrons in the Fields of Moving Charges
4 pages, 3 figures
null
10.1103/PhysRevA.76.050701
null
physics.atom-ph physics.comp-ph quant-ph
null
An ab initio, three-dimensional quantum mechanical calculation has been performed for the time-evolution of continuum electrons in the fields of moving charges. Here the essential singularity associated with the diverging phase factor in the continuum wave function is identified and removed analytically. As a result, the continuum components of the regularized wave function are slowly varying with time. Therefore, one can propagate continuum electrons to asymptotically large times and obtain numerically stable, well-converged ejected electron momentum spectra with very low numerical noise. As a consequence, our approach resolves outstanding controversies concerning structures in electron momentum distributions. The main conclusions are general and are illustrated here for ionization of atomic hydrogen by proton impact. Our results show that in order to obtain correct long-time free-particle propagation, the essential singularity identified here should be removed from the continuum components of solutions to the time-dependent Schrodinger equation.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 18:45:39 GMT" } ]
2009-11-13T00:00:00
[ [ "Lee", "Teck-Ghee", "", "ORNL & Univ. Kentucky" ], [ "Ovchinnikov", "S. Yu.", "", "ORNL &\n Univ. Tennessee" ], [ "Sternberg", "J.", "", "Univ. Tennessee" ], [ "Chupryna", "V.", "", "Univ.\n Tennessee" ], [ "Schultz", "D. R.", "", "ORNL" ], [ "Macek", "J. H.", "", "ORNL & Univ. Tennessee" ] ]
0708.2642
Monica Relano Pastor
M. Relano, U. Lisenfeld, P. G. Perez-Gonzalez, J. M. Vilchez, E. Battaner
On the metallicity dependence of the 24micron luminosity as a star formation tracer
accepted for publication in ApJ Letters
null
10.1086/522371
null
astro-ph
null
We investigate the use of the rest-frame 24microns luminosity as an indicator of the star formation rate (SFR) in galaxies with different metallicities by comparing it to the (extinction corrected) Halpha luminosity. We carry out this analysis in 2 steps: First, we compare the emission from HII regions in different galaxies with metallicities between 12+log(O/H) = 8.1 and 8.9. We find that the 24microns and the extinction corrected Halpha luminosities from individual HII regions follow the same correlation for all galaxies, independent of their metallicity. Second, the role of metallicity is explored further for the integrated luminosity in a sample of galaxies with metallicities in the range of 12+log(O/H) = 7.2 - 9.1. For this sample we compare the 24microns and Halpha luminosities integrated over the entire galaxies and find a lack of the 24microns emission for a given Halpha luminosity for low metallicity objects, likely reflecting a low dust content. These results suggest that the 24microns luminosity is a good metallicity independent tracer for the SFR in individual HII regions. On the other hand, metallicity has to be taken into account when using the 24microns luminosity as a tracer for the SFR of entire galaxies.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 11:32:07 GMT" } ]
2009-11-13T00:00:00
[ [ "Relano", "M.", "" ], [ "Lisenfeld", "U.", "" ], [ "Perez-Gonzalez", "P. G.", "" ], [ "Vilchez", "J. M.", "" ], [ "Battaner", "E.", "" ] ]
0708.2643
Jason Fulman
Persi Diaconis, Jason Fulman and Robert Guralnick
On fixed points of permutations
30 pages
null
null
null
math.CO math.GR
null
The number of fixed points of a random permutation of 1,2,...,n has a limiting Poisson distribution. We seek a generalization, looking at other actions of the symmetric group. Restricting attention to primitive actions, a complete classification of the limiting distributions is given. For most examples, they are trivial -- almost every permutation has no fixed points. For the usual action of the symmetric group on k-sets of 1,2,...,n, the limit is a polynomial in independent Poisson variables. This exhausts all cases. We obtain asymptotic estimates in some examples, and give a survey of related results.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 18:32:06 GMT" } ]
2007-08-21T00:00:00
[ [ "Diaconis", "Persi", "" ], [ "Fulman", "Jason", "" ], [ "Guralnick", "Robert", "" ] ]
0708.2644
Jie Xiao
Jie Xiao
Optimal Monotonicity of $L^p$ Integral of Conformal Invariant Green Function
25 pages
null
null
null
math.DG math.FA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Both analytic and geometric forms of an optimal monotone principle for $L^p$-integral of the Green function of a simply-connected planar domain $\Omega$ with rectifiable simple curve as boundary are established through a sharp one-dimensional power integral estimate of Riemann-Stieltjes type and the Huber analytic and geometric isoperimetric inequalities under finiteness of the positive part of total Gauss curvature of a conformal metric on $\Omega$. Consequently, new analytic and geometric isoperimetric-type inequalities are discovered. Furthermore, when applying the geometric principle to two-dimensional Riemannian manifolds, we find fortunately that $\{0,1\}$-form of the induced principle is midway between Moser-Trudinger's inequality and Nash-Sobolev's inequality on complete noncompact boundary-free surfaces, and yet equivalent to Nash-Sobolev's/Faber-Krahn's eigenvalue/Heat-kernel-upper-bound/Log-Sobolev's inequality on the surfaces with finite total Gauss curvature and quadratic area growth.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 18:30:36 GMT" }, { "version": "v2", "created": "Mon, 27 Aug 2007 14:42:42 GMT" }, { "version": "v3", "created": "Fri, 27 Jun 2008 18:34:48 GMT" }, { "version": "v4", "created": "Sun, 29 Jun 2008 20:02:10 GMT" }, { "version": "v5", "created": "Thu, 7 Aug 2008 14:03:38 GMT" }, { "version": "v6", "created": "Tue, 11 Aug 2009 18:00:18 GMT" } ]
2009-08-11T00:00:00
[ [ "Xiao", "Jie", "" ] ]
0708.2645
Joern Rossa
Joern Rossa (University of Florida), Seppo Laine (Spitzer Science Center, Caltech), Roeland P. van der Marel (STScI), J. Christopher Mihos (CWRU), John E. Hibbard (NRAO), Torsten Boeker (ESA/RSSD), Ann I. Zabludoff (University of Arizona)
The Toomre Sequence Revisited with HST/NICMOS: Nuclear Brightness Profiles and Colors of Interacting and Merging Galaxies
46 pages, 25 figures, accepted for publication in AJ, article with full resolution images is available at http://www.stsci.edu/~marel/psgzdir/toomrenir.ps.gz
Astron.J.134:2124-2147,2007
10.1086/522782
null
astro-ph
null
We discuss the near-infrared properties of the nuclei in the 11 merging galaxies of the Toomre sequence, based on high spatial resolution J, H, and K imaging data using NICMOS onboard the Hubble Space Telescope (HST). The observations are less affected by dust extinction than our previous HST/WFPC2 observations and offer higher spatial resolution than existing ground-based near-IR data. We see a marginal trend for the nuclei to become bluer with advancing merger stage, which we attribute to a dispersal of dust at late times in the merging process. Our data also indicate a statistically significant trend for the nuclei in the sequence to become more luminous, within an aperture of fixed physical size and after correcting for dust extinction, with advancing merger stage. We derive K-band surface brightness profiles for those nuclei for which the morphology allows a meaningful isophotal analysis, and fit the profiles with a ``Nuker law'' for comparison with other samples of galaxies observed with HST. The majority of the nuclei have steep profiles that can be characterized as power-law type. In general, the Toomre sequence galaxies tend to have steeper profiles and higher central luminosity surface densities than E/S0's. We derive V-K color profiles for the nuclei to further address this possibility, but find that the large amounts of dust extinction complicate their interpretation. Overall, our results are consistent with the generic predictions of N-body simulations of spiral galaxy mergers. If left to evolve and fade for several Gyrs, it is possible that the properties of the Toomre sequence nuclei would resemble theproperties of the nuclei of normal E/S0 galaxies. Our results therefore support the view that mergers of spiral galaxies can lead to the formation of early-type galaxies (Abridged).
[ { "version": "v1", "created": "Mon, 20 Aug 2007 18:26:59 GMT" } ]
2008-11-26T00:00:00
[ [ "Rossa", "Joern", "", "University of Florida" ], [ "Laine", "Seppo", "", "Spitzer Science\n Center, Caltech" ], [ "van der Marel", "Roeland P.", "", "STScI" ], [ "Mihos", "J. Christopher", "", "CWRU" ], [ "Hibbard", "John E.", "", "NRAO" ], [ "Boeker", "Torsten", "", "ESA/RSSD" ], [ "Zabludoff", "Ann I.", "", "University of Arizona" ] ]
0708.2646
Alexander S. Sakharov
A. Rubbia (ETH-Zurich) and A.S. Sakharov (ETH-Zurich, CERN)
Constraining axion by polarized prompt emission from gamma ray bursts
9 pages, 1 figure
Astropart.Phys.29:20-24,2008
10.1016/j.astropartphys.2007.11.003
CERN-TH/2007-146
hep-ph astro-ph gr-qc hep-th
null
A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of invisible axion. The axionic induced dichroism of gamma rays at different energies should cause a misalignment of the polarization plane for higher energy events relative to that one for lower energies events resulting in the loss of statistics needed to form a pattern of the polarization signal to be recognized in a detector. According to this, any evidence of polarized gamma rays coming from an object with extended magnetic field could be interpreted as a constraint on the existence of the invisible axion for a certain parameter range. Based on reports of polarized MeV emission detected in several GRBs we derive a constraint on the axion-photon coupling. This constraint $\g_{a\gamma\gamma}\le 2.2\cdot 10^{-11} {\rm GeV^{-1}}$ calculated for the axion mass $m_a=10^{-3} {\rm eV}$ is competitive with the sensitivity of CAST and becomes even stronger for lower masses.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 12:38:22 GMT" }, { "version": "v2", "created": "Mon, 20 Aug 2007 23:44:51 GMT" }, { "version": "v3", "created": "Tue, 21 Aug 2007 20:38:12 GMT" } ]
2008-11-26T00:00:00
[ [ "Rubbia", "A.", "", "ETH-Zurich" ], [ "Sakharov", "A. S.", "", "ETH-Zurich, CERN" ] ]
0708.2647
David Hochberg
David Hochberg and Maria-Paz Zorzano
Mirror symmetry breaking as a problem in dynamical critical phenomena
9 pages, 3 figures
Physical Review E76, 021109 (2007)
10.1103/PhysRevE.76.021109
null
q-bio.PE cond-mat.stat-mech
null
The critical properties of the Frank model of spontaneous chiral synthesis are discussed by applying results from the field theoretic renormalization group (RG). The long time and long wavelength features of this microscopic reaction scheme belong to the same universality class as multi-colored directed percolation processes. Thus, the following RG fixed points (FP) govern the critical dynamics of the Frank model for d<4: one unstable FP that corresponds to complete decoupling between the two enantiomers, a saddle-point that corresponds to symmetric interspecies coupling, and two stable FPs that individually correspond to unidirectional couplings between the two chiral molecules. These latter two FPs are associated with the breakdown of mirror or chiral symmetry. In this simplified model of molecular synthesis, homochirality is a natural consequence of the intrinsic reaction noise in the critical regime, which corresponds to extremely dilute chemical systems.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 12:10:55 GMT" } ]
2007-08-23T00:00:00
[ [ "Hochberg", "David", "" ], [ "Zorzano", "Maria-Paz", "" ] ]
0708.2648
Richard Szabo
Jacek Brodzki, Varghese Mathai, Jonathan Rosenberg and Richard J. Szabo
Noncommutative correspondences, duality and D-branes in bivariant K-theory
36 pages
Adv.Theor.Math.Phys.13:497-552,2009
null
HWM-07-25, EMPG-07-16
hep-th math.KT
null
We describe a categorical framework for the classification of D-branes on noncommutative spaces using techniques from bivariant K-theory of C*-algebras. We present a new description of bivariant K-theory in terms of noncommutative correspondences which is nicely adapted to the study of T-duality in open string theory. We systematically use the diagram calculus for bivariant K-theory as detailed in our previous paper. We explicitly work out our theory for a number of examples of noncommutative manifolds.
[ { "version": "v1", "created": "Mon, 20 Aug 2007 12:46:29 GMT" } ]
2009-07-07T00:00:00
[ [ "Brodzki", "Jacek", "" ], [ "Mathai", "Varghese", "" ], [ "Rosenberg", "Jonathan", "" ], [ "Szabo", "Richard J.", "" ] ]