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0705.0098
Robin de Jong
Robin de Jong
Gauss map on the theta divisor and Green's functions
10 pages, in: B. Edixhoven, G. van der Geer and B. Moonen (eds.), Modular Forms on Schiermonnikoog. Cambridge University Press 2008
null
null
null
math.AG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In an earlier paper we constructed a Cartier divisor on the theta divisor of a principally polarised abelian variety whose support is precisely the ramification locus of the Gauss map. In this note we discuss a Green's function associated to this locus. For jacobians we relate this Green's function to the canonical Green's function of the corresponding Riemann surface.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:01:17 GMT" }, { "version": "v2", "created": "Wed, 2 May 2012 15:02:20 GMT" } ]
2012-05-03T00:00:00
[ [ "de Jong", "Robin", "" ] ]
0705.0099
Gian Michele Graf
Joseph E. Avron, Sven Bachmann, Gian Michele Graf, Israel Klich
Fredholm determinants and the statistics of charge transport
30 pages, 2 figures, reference added, credit amended
null
10.1007/s00220-008-0449-x
null
math-ph cond-mat.mes-hall math.MP
null
Using operator algebraic methods we show that the moment generating function of charge transport in a system with infinitely many non-interacting Fermions is given by a determinant of a certain operator in the one-particle Hilbert space. The formula is equivalent to a formula of Levitov and Lesovik in the finite dimensional case and may be viewed as its regularized form in general. Our result embodies two tenets often realized in mesoscopic physics, namely, that the transport properties are essentially independent of the length of the leads and of the depth of the Fermi sea.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:07:52 GMT" }, { "version": "v2", "created": "Mon, 14 May 2007 16:45:52 GMT" }, { "version": "v3", "created": "Thu, 16 Aug 2007 13:30:05 GMT" } ]
2009-11-13T00:00:00
[ [ "Avron", "Joseph E.", "" ], [ "Bachmann", "Sven", "" ], [ "Graf", "Gian Michele", "" ], [ "Klich", "Israel", "" ] ]
0705.0100
Dhananjay Mehendale
Dhananjay P. Mehendale
On Hadwiger Conjecture
11 pages. Theorem 5.1 is extended to incorporate the graphs which themselves are less than k-chromatic but have arrived at by suitable contractions, in the sense of algorithm 5.1, from a k-chromatic graph
null
null
null
math.GM
null
We propose an algorithm to reduce a k-chromatic graph to a complete graph of largest possible order through a well defined sequence of contractions. We introduce a new matrix called transparency matrix and state its properties. We then define correct contraction procedure to be executed to get largest possible complete graph from given connected graph. We finally give a characterization for k-chromatic graphs and use it to settle Hadwigers conjecture.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:19:56 GMT" }, { "version": "v2", "created": "Tue, 8 May 2007 13:09:27 GMT" }, { "version": "v3", "created": "Sat, 12 May 2007 04:28:55 GMT" }, { "version": "v4", "created": "Sat, 16 Jun 2007 09:59:58 GMT" }, { "version": "v5", "created": "Thu, 21 Jun 2007 04:17:42 GMT" } ]
2007-06-21T00:00:00
[ [ "Mehendale", "Dhananjay P.", "" ] ]
0705.0101
Qiang Zhao
Qiang Zhao
\chi_{c0,2} decay into light meson pairs and its implication of the scalar meson structures
Minor modifications; Revised version accepted by Phys. Lett. B
Phys.Lett.B659:221-227,2008
10.1016/j.physletb.2007.10.062
null
hep-ph hep-ex
null
In light of the recent data from BES collaboration for $\chi_{c0}\to VV$, $PP$ and $SS$, and from CLEO-c for $\eta\eta$, $\eta^\prime\eta^\prime$ and $\eta\eta^\prime$, we present a detailed analysis of the decays of heavy quarkonia into light meson pairs such as $\chi_{c0,2}\to VV$, $PP$ and $SS$ in a recently proposed parametrization scheme. An overall agreement with the data is achieved in $\chi_{c0,2}\to VV$ and $PP$, while in $\chi_{c0}\to SS$ we find that a possible existence of glueball-$q\bar{q}$ mixings is correlated with the OZI-rule violations, which can be further examined at CLEO-c and BESIII in $\chi_{c0}\to SS$ measurement.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:26:15 GMT" }, { "version": "v2", "created": "Wed, 31 Oct 2007 00:55:25 GMT" } ]
2008-11-26T00:00:00
[ [ "Zhao", "Qiang", "" ] ]
0705.0102
David Pauksztello
David Pauksztello
Compact Corigid Objects in Triangulated Categories and Co-t-structures
21 pages, reorganised paper with added material and examples of t-structures and co-t-structures
null
null
null
math.CT
null
In the work of Hoshino, Kato and Miyachi, the authors look at t-structures induced by a compact object, C, of a triangulated category, T, which is rigid in the sense of Iyama and Yoshino. Hoshino, Kato and Miyachi show that such an object yields a non-degenerate t-structure on T whose heart es equivalent to Mod(End(C)^op). Rigid objects in a triangulated category can be thought of as behaving like chain differential graded algebras (DGAs). Analogously, looking at objects which behave like cochain DGAs naturally gives the dual notion of a corigid object. Here, we see that a compact corigid object, S, of a triangulated category, T, induces a structure similar to a t-structure which we shall call a co-t-structure. We also show that the coheart of this non-degenerate co-t-structure is equivalent to Mod(End(S)^op), and hence an abelian subcategory of T.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:39:31 GMT" }, { "version": "v2", "created": "Tue, 23 Oct 2007 13:58:05 GMT" } ]
2007-10-23T00:00:00
[ [ "Pauksztello", "David", "" ] ]
0705.0103
Reza Asgari
N. Abedpour, M. Neek-Amal, Reza Asgari, F. Shahbazi, N. Nafari, M. Reza Rahimi Tabar
Roughness of undoped graphene and its short-range induced gauge field
5 Pages, 5 figures
Phys. Rev. B 76, 195407 (2007)
10.1103/PhysRevB.76.195407
null
cond-mat.mtrl-sci cond-mat.str-el
null
We present both numerical and analytical study of graphene roughness with a crystal structure including $500 \times 500$ atoms. The roughness can effectively result in a random gauge field and has important consequences for its electronic structure. Our results show that its height fluctuations in small scales have scaling behavior with a temperature dependent roughness exponent in the interval of $ 0.6 < \chi < 0.7 $. The correlation function of height fluctuations depends upon temperature with characteristic length scale of $ \approx 90 {\AA}$ (at room temperature). We show that the correlation function of the induced gauge field has a short-range nature with correlation length of about $\simeq 2-3 {\AA}$. We also treat the problem analytically by using the Martin-Siggia-Rose method. The renormalization group flows did not yield any delocalized-localized transition arising from the graphene roughness. Our results are in good agreement with recent experimental observations.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:03:58 GMT" }, { "version": "v2", "created": "Thu, 8 Nov 2007 05:38:47 GMT" } ]
2009-11-13T00:00:00
[ [ "Abedpour", "N.", "" ], [ "Neek-Amal", "M.", "" ], [ "Asgari", "Reza", "" ], [ "Shahbazi", "F.", "" ], [ "Nafari", "N.", "" ], [ "Tabar", "M. Reza Rahimi", "" ] ]
0705.0104
Markus Bier
Markus Bier and Rene van Roij
Relaxation dynamics in fluids of platelike colloidal particles
low-resolution figures due to file size restrictions, revised version
Phys. Rev. E 76, 021405 (2007)
10.1103/PhysRevE.76.021405
null
cond-mat.soft
null
The relaxation dynamics of a model fluid of platelike colloidal particles is investigated by means of a phenomenological dynamic density functional theory. The model fluid approximates the particles within the Zwanzig model of restricted orientations. The driving force for time-dependence is expressed completely by gradients of the local chemical potential which in turn is derived from a density functional -- hydrodynamic interactions are not taken into account. These approximations are expected to lead to qualitatively reliable results for low densities as those within the isotropic-nematic two-phase region. The formalism is applied to model an initially spatially homogeneous stable or metastable isotropic fluid which is perturbed by switching a two-dimensional array of Gaussian laser beams. Switching on the laser beams leads to an accumulation of colloidal particles in the beam centers. If the initial chemical potential and the laser power are large enough a preferred orientation of particles occurs breaking the symmetry of the laser potential. After switching off the laser beams again the system can follow different relaxation paths: It either relaxes back to the homogeneous isotropic state or it forms an approximately elliptical high-density core which is elongated perpendicular to the dominating orientation in order to minimize the surface free energy. For large supersaturations of the initial isotropic fluid the high-density cores of neighboring laser beams of the two-dimensional array merge into complex superstructures.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:44:38 GMT" }, { "version": "v2", "created": "Fri, 8 Jun 2007 15:10:48 GMT" } ]
2011-09-14T00:00:00
[ [ "Bier", "Markus", "" ], [ "van Roij", "Rene", "" ] ]
0705.0105
Arnab Bhattacharya
Abdul Kadir, Tapas Ganguli, Ravi Kumar, M.R. Gokhale, A.P. Shah, B.M. Arora and Arnab Bhattacharya
Influence of growth parameters on structural properties and bandgap of InN epilayers deposited in a showerhead MOVPE system
4 pages, 2 figures
null
null
null
cond-mat.mtrl-sci cond-mat.other
null
From a detailed analysis of InN epilayers deposited in a close-coupled showerhead metalorganic vapour phase epitaxy (MOVPE) system under various conditions we investigate the effect of growth parameters on the lattice constants of the InN layer. The layers are under significant internal hydrostatic stress which influences the optical properties. Samples typically fall into two broad categories of stress, with resultant luminescence emission around 0.8eV and 1.1eV. We can correlate the internal stress in the layer and the value of the optical absorption edge, and the PL emission wavelength.
[ { "version": "v1", "created": "Tue, 1 May 2007 12:47:04 GMT" } ]
2007-05-23T00:00:00
[ [ "Kadir", "Abdul", "" ], [ "Ganguli", "Tapas", "" ], [ "Kumar", "Ravi", "" ], [ "Gokhale", "M. R.", "" ], [ "Shah", "A. P.", "" ], [ "Arora", "B. M.", "" ], [ "Bhattacharya", "Arnab", "" ] ]
0705.0106
Aaron Keys
Aaron S. Keys and Sharon C. Glotzer
How Do Quasicrystals Grow?
4 pages, 4 figures. Figures and text have been updated to the final version of the article
Phys. Rev. Lett. 99, pp. 235503 (2007)
10.1103/PhysRevLett.99.235503
null
cond-mat.other
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using molecular simulations, we show that the aperiodic growth of quasicrystals is controlled by the ability of the growing quasicrystal `nucleus' to incorporate kinetically trapped atoms into the solid phase with minimal rearrangement. In the system under investigation, which forms a dodecagonal quasicrystal, we show that this process occurs through the assimilation of stable icosahedral clusters by the growing quasicrystal. Our results demonstrate how local atomic interactions give rise to the long-range aperiodicity of quasicrystals.
[ { "version": "v1", "created": "Mon, 30 Apr 2007 19:42:31 GMT" }, { "version": "v2", "created": "Wed, 2 May 2007 19:25:57 GMT" }, { "version": "v3", "created": "Tue, 21 Dec 2010 05:03:22 GMT" } ]
2010-12-22T00:00:00
[ [ "Keys", "Aaron S.", "" ], [ "Glotzer", "Sharon C.", "" ] ]
0705.0107
Thomas Schwetz
Michele Maltoni, Thomas Schwetz
Sterile neutrino oscillations after first MiniBooNE results
30 pages, 12 figures, minor improvements of text and abstract, summary table added, matches version to be published in Phys. Rev. D
Phys.Rev.D76:093005,2007
10.1103/PhysRevD.76.093005
IFT-UAM/CSIC-07-19, CERN-PH-TH/2007-075
hep-ph
null
In view of the recent results from the MiniBooNE experiment we revisit the global neutrino oscillation fit to short-baseline neutrino data by adding one or two sterile neutrinos with eV-scale masses to the three Standard Model neutrinos, and for the first time we consider also the global fit with three sterile neutrinos. Four-neutrino oscillations of the (3+1) type have been only marginally allowed before the recent MiniBooNE results, and become even more disfavored with the new data (at the level of $4\sigma$). In the framework of so-called (3+2) five-neutrino mass schemes we find severe tension between appearance and disappearance experiments at the level of more than $3\sigma$, and hence no satistfactory fit to the global data is possible in (3+2) schemes. This tension remains also when a third sterile neutrino is added, and the quality of the global fit does not improve significantly in a (3+3) scheme. It should be noted, however, that in models with more than one sterile neutrino the MiniBooNE results are in perfect agreement with the LSND appearance evidence, thanks to the possibility of CP violation available in such oscillation schemes. Furthermore, if disappearance data are not taken into account (3+2) oscillations provide an excellent fit to the full MiniBooNE spectrum including the event excess at low energies.
[ { "version": "v1", "created": "Tue, 1 May 2007 13:37:19 GMT" }, { "version": "v2", "created": "Thu, 14 Jun 2007 11:44:12 GMT" }, { "version": "v3", "created": "Tue, 2 Oct 2007 07:31:50 GMT" } ]
2008-11-26T00:00:00
[ [ "Maltoni", "Michele", "" ], [ "Schwetz", "Thomas", "" ] ]
0705.0108
Lars M. Johansen
Lars M. Johansen
Reconstructing weak values without weak measurements
6 pages. Accepted in Phys. Lett. A
Phys. Lett. A 366 (2007) 374-376
10.1016/j.physleta.2007.02.039
null
quant-ph
null
I propose a scheme for reconstructing the weak value of an observable without the need for weak measurements. The post-selection in weak measurements is replaced by an initial projector measurement. The observable can be measured using any form of interaction, including projective measurements. The reconstruction is effected by measuring the change in the expectation value of the observable due to the projector measurement. The weak value may take nonclassical values if the projector measurement disturbs the expectation value of the observable.
[ { "version": "v1", "created": "Tue, 1 May 2007 13:35:45 GMT" } ]
2007-06-13T00:00:00
[ [ "Johansen", "Lars M.", "" ] ]
0705.0109
Richard Hendricks
R.J. Hendricks, D.M. Grant, P.F. Herskind, A. Dantan, M. Drewsen
An all-optical ion-loading technique for scalable microtrap architectures
8 pages, 9 figures
Appl. Phys. B 88, 507 (2007)
10.1007/s00340-007-2698-3
null
quant-ph
null
An experimental demonstration of a novel all-optical technique for loading ion traps, that has particular application to microtrap architectures, is presented. The technique is based on photo-ionisation of an atomic beam created by pulsed laser ablation of a calcium target, and provides improved temporal control compared to traditional trap loading methods. Ion loading rates as high as 125 ions per second have so far been observed. Also described are observations of trap loading where Rydberg state atoms are photo-ionised by the ion Doppler cooling laser.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:14:03 GMT" } ]
2012-02-10T00:00:00
[ [ "Hendricks", "R. J.", "" ], [ "Grant", "D. M.", "" ], [ "Herskind", "P. F.", "" ], [ "Dantan", "A.", "" ], [ "Drewsen", "M.", "" ] ]
0705.0110
Alan Russell
A. Russell, Vladimir I. Fal'ko, A. I. Tartakovskii and M. S. Skolnick
Bistability of optically-induced nuclear spin orientation in quantum dots
4 pages, 4 figures
null
10.1103/PhysRevB.76.195310
null
cond-mat.mes-hall
null
We demonstrate that bistability of the nuclear spin polarization in optically pumped semiconductor quantum dots is a general phenomenon possible in dots with a wide range of parameters. In experiment, this bistability manifests itself via the hysteresis behavior of the electron Zeeman splitting as a function of either pump power or external magnetic field. In addition, our theory predicts that the nuclear polarization can strongly influence the charge dynamics in the dot leading to bistability in the average dot charge.
[ { "version": "v1", "created": "Tue, 1 May 2007 13:53:48 GMT" } ]
2009-11-13T00:00:00
[ [ "Russell", "A.", "" ], [ "Fal'ko", "Vladimir I.", "" ], [ "Tartakovskii", "A. I.", "" ], [ "Skolnick", "M. S.", "" ] ]
0705.0111
Christian Bernhard
Li Yu, D. Munzar, A.V. Boris, P. Yordanov, J. Chaloupka, Th. Wolf, C.T. Lin, B. Keimer, and C. Bernhard
Spectroscopic distinction between the normal state pseudogap and the superconducting gap of cuprate high T_{c} superconductors
4 pages, 4 figures
Phys. Rev. Lett. 100, 177004 (2008)
10.1103/PhysRevLett.100.177004
null
cond-mat.supr-con cond-mat.str-el
null
We report on broad-band infrared ellipsometry measurements of the c-axis conductivity of underdoped RBa_{2}Cu_{3}O_{7-d} (R=Y, Nd, and La) single crystals. Our data provide a detailed account of the spectral weight (SW) redistributions due to the normal state pseudogap (PG) and the superconducting (SC) gap. They show that these phenomena involve different energy scales, exhibit distinct doping dependencies and thus are likely of different origin. In particular, the SW redistribution in the PG state closely resembles the one of a conventional charge- or spin density wave (CDW or SDW) system.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:11:20 GMT" } ]
2015-05-13T00:00:00
[ [ "Yu", "Li", "" ], [ "Munzar", "D.", "" ], [ "Boris", "A. V.", "" ], [ "Yordanov", "P.", "" ], [ "Chaloupka", "J.", "" ], [ "Wolf", "Th.", "" ], [ "Lin", "C. T.", "" ], [ "Keimer", "B.", "" ], [ "Bernhard", "C.", "" ] ]
0705.0112
Joaquin Diaz Alonso
Joaquin Diaz-Alonso and Diego Rubiera-Garcia
Non-topological solitons in field theories with kinetic self-coupling
5 pages, 1 figure, revtex4, minor corrections added
Phys.Lett.B653:445-449,2007
10.1016/j.physletb.2007.08.025
null
hep-th
null
We investigate some fundamental features of a class of non-linear relativistic lagrangian field theories with kinetic self-coupling. We focus our attention upon theories admitting static, spherically symmetric solutions in three space dimensions which are finite-energy and stable. We determine general conditions for the existence and stability of these non-topological soliton solutions. In particular, we perform a linear stability analysis that goes beyond the usual Derrick-like criteria. On the basis of these considerations we obtain a complete characterization of the soliton-supporting members of the aforementioned class of non-linear field theories. We then classify the family of soliton-supporting theories according to the central and asymptotic behaviors of the soliton field, and provide illustrative explicit examples of models belonging to each of the corresponding sub-families. In the present work we restrict most of our considerations to one and many-components scalar models. We show that in these cases the finite-energy static spherically symmetric solutions are stable against charge-preserving perturbations, provided that the vacuum energy of the model vanishes and the energy density is positive definite. We also discuss briefly the extension of the present approach to models involving other types of fields, but a detailed study of this more general scenario will be addressed in a separate publication.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:16:24 GMT" }, { "version": "v2", "created": "Tue, 7 Aug 2007 10:39:48 GMT" } ]
2008-11-26T00:00:00
[ [ "Diaz-Alonso", "Joaquin", "" ], [ "Rubiera-Garcia", "Diego", "" ] ]
0705.0113
Javier Guachalla H.
Javier Guachalla H
The Mathematics
53 pages, 4 figures
null
null
null
math.HO
null
This is an essay that considering the knowledge structure and language of a different nature, attempts to build on an explanation of the object of study and characteristics of the mathematical science. We end up with a learning cycle of mathematics and a paradigm for education, namely Learn to structure.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:20:33 GMT" }, { "version": "v2", "created": "Thu, 10 May 2007 04:37:55 GMT" } ]
2007-05-25T00:00:00
[ [ "H", "Javier Guachalla", "" ] ]
0705.0114
Casey Law
Casey James Law
Surveys of the Galactic Center and the Nature of the Galactic Center Lobe
PhD dissertation at Northwestern University. Figures in this version were modified for astro-ph; original version can be found at http://staff.science.uva.nl/~claw/thesis_claw.pdf
null
10.5281/zenodo.51892
null
astro-ph
null
The Galactic center (GC) is a dense and chaotic region filled with unusual sources, such as intense star forming regions, dense star clusters, nonthermal radio filaments, and a massive black hole. The proximity of the GC region makes it an ideal place to study the unusual processes that tend to manifest themselves in Galactic nuclei. This thesis uses single-dish and interferometric radio continuum, radio recombination line, polarized radio continuum, and mid-IR observations to study the wide variety of physical processes seen in the GC region on physical scales from 0.1 to 100 parsecs. These observations provide one of the most sensitive studies of the radio continuum emission in the central 500 parsecs. I also study the properties of nonthermal radio filaments, which can constrain their origin and the structure of the magnetic field in the GC region. The presence of massive star clusters and a massive black hole suggest that starburst and AGN phenomena can manifest themselves in our Galaxy. This thesis explores this possibility by studying a 150-pc-tall, shell-like structure called the Galactic center lobe (GCL). Our observations examine the spectral index, dust emission, polarized continuum emission, and ionized gas throughout the GCL. I find strong evidence supporting the idea that the GCL is a true three-dimensional shell located in the GC region with nested layers of ionized, magnetized, and mid-IR--emitting components. I compare the physical conditions of the GCL to proposed models for its origin and find best agreement with starburst outflows seen in other galaxies, yet consistent with the currently observed pressure and star formation rate in the central tens of parsecs of our Galaxy. (abridged)
[ { "version": "v1", "created": "Tue, 1 May 2007 13:40:16 GMT" } ]
2016-06-22T00:00:00
[ [ "Law", "Casey James", "" ] ]
0705.0115
Wang Qing
Hong-Hao Zhang, Shao-Zhou Jiang, Qing Wang
Dynamical Computation on Coefficients of Electroweak Chiral Lagrangian from One-doublet and Topcolor-assisted Technicolor Models
52 pages, 15 figures
Phys.Rev.D77:055003,2008
10.1103/PhysRevD.77.055003
TUHEP-TH-07157
hep-ph
null
Based on previous studies deriving the chiral Lagrangian for pseudo scalar mesons from the first principle of QCD, we derive the electroweak chiral Lagrangian and build up a formulation for computing its coefficients from one-doublet technicolor model and a schematic topcolor-assisted technicolor model. We find that the coefficients of the electroweak chiral Lagrangian for the topcolor-assisted technicolor model are divided into three parts: direct TC2 interaction part, TC1 and TC2 induced effective Z' particle contribution part, and ordinary quarks contribution part. The first two parts are computed in this paper and we show that the direct TC2 interaction part is the same as that in the one-doublet technicolor model, while effective Z' contributions are at least proportional to the p^2 order parameter \beta_1 in the electroweak chiral Lagrangian and typical features of topcolor-assisted technicolor model are that it only allows positive T and U parameters and the T parameter varies in the range 0\sim 1/(25\alpha), the upper bound of T parameter will decrease as long as Z' mass become large. The S parameter can be either positive or negative depending on whether the Z' mass is large or small. The Z' mass is also bounded above and the upper bound depend on value of T parameter. We obtain the values for all the coefficients of the electroweak chiral Lagrangian up to order of p^4.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:28:08 GMT" }, { "version": "v2", "created": "Wed, 2 May 2007 05:01:39 GMT" } ]
2008-11-26T00:00:00
[ [ "Zhang", "Hong-Hao", "" ], [ "Jiang", "Shao-Zhou", "" ], [ "Wang", "Qing", "" ] ]
0705.0116
Campagne Jean-Eric
D. Autiero, J. Aysto, A. Badertscher, L. Bezrukov, J. Bouchez, A. Bueno, J. Busto, J.-E. Campagne, Ch. Cavata, L. Chaussard, A. de Bellefon, Y. Declais, J. Dumarchez, J. Ebert, T. Enqvist, A. Ereditato, F. von Feilitzsch, P. Fileviez Perez, M. Goger-Neff, S. Gninenko, W. Gruber, C. Hagner, M. Hess, K. A. Hochmuth, J. Kisiel, L. Knecht, I. Kreslo, V. A. Kudryavtsev, P. Kuusiniemi, T. Lachenmaier, M. Laffranchi, B. Lefievre, P. K. Lightfoot, M. Lindner, J. Maalampi, M. Maltoni, A. Marchionni, T. Marrodan Undagoitia, J. Marteau, A. Meregaglia, M. Messina, M. Mezzetto, A. Mirizzi, L. Mosca, U. Moser, A. Muller, G. Natterer, L. Oberauer, P. Otiougova, T. Patzak, J. Peltoniemi, W. Potzel, C .Pistillo, G.G. Raffelt, E. Rondio, M. Roos, B. Rossi, A. Rubbia, N. Savvinov, T. Schwetz, J. Sobczyk, N. J. C. Spooner, D. Stefan, A. Tonazzo, W. Trzaska, J. Ulbricht, C. Volpe, J. Winter, M. Wurm, A. Zalewska, R. Zimmermann
Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects
50 pages, 26 figures
JCAP 0711:011,2007
10.1088/1475-7516/2007/11/011
null
hep-ph
null
This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large-scale particle detectors proposed in Europe as next generation underground observatories. The proposed apparatus employ three different and, to some extent, complementary detection techniques: GLACIER (liquid Argon TPC), LENA (liquid scintillator) and MEMPHYS (\WC), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to open and outstanding physics issues such as the search for matter instability, the detection of astrophysical- and geo-neutrinos and to the possible use of these detectors in future high-intensity neutrino beams.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:45:11 GMT" }, { "version": "v2", "created": "Tue, 29 May 2007 13:50:28 GMT" } ]
2009-02-11T00:00:00
[ [ "Autiero", "D.", "" ], [ "Aysto", "J.", "" ], [ "Badertscher", "A.", "" ], [ "Bezrukov", "L.", "" ], [ "Bouchez", "J.", "" ], [ "Bueno", "A.", "" ], [ "Busto", "J.", "" ], [ "Campagne", "J. -E.", "" ], [ "Cavata", "Ch.", "" ], [ "Chaussard", "L.", "" ], [ "de Bellefon", "A.", "" ], [ "Declais", "Y.", "" ], [ "Dumarchez", "J.", "" ], [ "Ebert", "J.", "" ], [ "Enqvist", "T.", "" ], [ "Ereditato", "A.", "" ], [ "von Feilitzsch", "F.", "" ], [ "Perez", "P. Fileviez", "" ], [ "Goger-Neff", "M.", "" ], [ "Gninenko", "S.", "" ], [ "Gruber", "W.", "" ], [ "Hagner", "C.", "" ], [ "Hess", "M.", "" ], [ "Hochmuth", "K. A.", "" ], [ "Kisiel", "J.", "" ], [ "Knecht", "L.", "" ], [ "Kreslo", "I.", "" ], [ "Kudryavtsev", "V. A.", "" ], [ "Kuusiniemi", "P.", "" ], [ "Lachenmaier", "T.", "" ], [ "Laffranchi", "M.", "" ], [ "Lefievre", "B.", "" ], [ "Lightfoot", "P. K.", "" ], [ "Lindner", "M.", "" ], [ "Maalampi", "J.", "" ], [ "Maltoni", "M.", "" ], [ "Marchionni", "A.", "" ], [ "Undagoitia", "T. Marrodan", "" ], [ "Marteau", "J.", "" ], [ "Meregaglia", "A.", "" ], [ "Messina", "M.", "" ], [ "Mezzetto", "M.", "" ], [ "Mirizzi", "A.", "" ], [ "Mosca", "L.", "" ], [ "Moser", "U.", "" ], [ "Muller", "A.", "" ], [ "Natterer", "G.", "" ], [ "Oberauer", "L.", "" ], [ "Otiougova", "P.", "" ], [ "Patzak", "T.", "" ], [ "Peltoniemi", "J.", "" ], [ "Potzel", "W.", "" ], [ "Pistillo", "C .", "" ], [ "Raffelt", "G. G.", "" ], [ "Rondio", "E.", "" ], [ "Roos", "M.", "" ], [ "Rossi", "B.", "" ], [ "Rubbia", "A.", "" ], [ "Savvinov", "N.", "" ], [ "Schwetz", "T.", "" ], [ "Sobczyk", "J.", "" ], [ "Spooner", "N. J. C.", "" ], [ "Stefan", "D.", "" ], [ "Tonazzo", "A.", "" ], [ "Trzaska", "W.", "" ], [ "Ulbricht", "J.", "" ], [ "Volpe", "C.", "" ], [ "Winter", "J.", "" ], [ "Wurm", "M.", "" ], [ "Zalewska", "A.", "" ], [ "Zimmermann", "R.", "" ] ]
0705.0117
James Hoskisson Mr
James Hoskisson
Particle Motion in the Rotating Black Ring Metric
36 pages, 19 figures, updated references, section 5 modified to remove ambiguity in discussion
Phys.Rev.D78:064039,2008
10.1103/PhysRevD.78.064039
DCPT-07/17
hep-th gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the equations of motion for geodesics in the neutral rotating Black Ring metric are derived and the separability of these equations is considered. The bulk of the paper is concerned with sets of solutions where the geodesic equations can be examined analytically - specifically geodesics confined to the axis of rotation, geodesics restricted to the equatorial plane, and geodesics that circle through the centre of the ring. The geodesics on the rotational axis behave like a particle in a potential well, while the geodesics confined to the equatorial plane mimic those of the Schwarzschild metric. It is shown that it is impossible to have circular orbits that pass through the ring, but some numerical results are presented which suggest that it is possible to have bound orbits that circle through the ring.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:06:00 GMT" }, { "version": "v2", "created": "Fri, 3 Aug 2007 15:50:45 GMT" }, { "version": "v3", "created": "Sat, 1 Dec 2007 19:42:10 GMT" }, { "version": "v4", "created": "Tue, 10 Feb 2009 17:34:06 GMT" } ]
2009-09-29T00:00:00
[ [ "Hoskisson", "James", "" ] ]
0705.0118
David Pauksztello
David Pauksztello
Homological Epimorphisms of Differential Graded Algebras
14 pages
null
10.1080/00927870802623344
null
math.RA
null
Let R and S be differential graded algebras. In this paper we give a characterisation of when a differential graded R-S-bimodule M induces a full embedding of derived categories M\otimes - :D(S)--> D(R). In particular, this characterisation generalises the theory of Geigle and Lenzing's homological epimorphisms of rings. Furthermore, there is an application of the main result to Dwyer and Greenlees's Morita theory.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:57:49 GMT" } ]
2010-06-03T00:00:00
[ [ "Pauksztello", "David", "" ] ]
0705.0119
Werner Becker
W. Becker, C.Y. Hui
A search for X-ray counterparts of the millisecond pulsars in the globular cluster M28 (NGC 6626)
Submitted for publication to Astronomy & Astrophysics Letter
null
null
null
astro-ph
null
A recent radio survey of globular clusters has increased the number of millisecond pulsars drastically. M28 is now the globular cluster with the third largest population of known pulsars, after Terzan 5 and 47 Tuc. This prompted us to revisit the archival Chandra data on M28 to evaluate whether the newly discovered millisecond pulsars find a counterpart among the various X-ray sources detected in M28 previously. The radio position of PSR J1824-2452H is found to be in agreement with the position of CXC 182431-245217 while some faint unresolved X-ray emission near to the center of M28 is found to be coincident with the millisecond pulsars PSR J1824-2452G, J1824-2452J, J1824-2452I and J1824-2452E.
[ { "version": "v1", "created": "Tue, 1 May 2007 14:57:59 GMT" } ]
2007-05-23T00:00:00
[ [ "Becker", "W.", "" ], [ "Hui", "C. Y.", "" ] ]
0705.0120
Marco Bertola
Marco Bertola, Mikael Gekhtman
Effective inverse spectral problem for rational Lax matrices and applications
33 pages. Version 2 with added references suggested by the referee
Int. Math. Res. Not. 2007 2007:rnm103-39
10.1093/imrn/rnm103
CRM-3239
nlin.SI
null
We reconstruct a rational Lax matrix of size R+1 from its spectral curve (the desingularization of the characteristic polynomial) and some additional data. Using a twisted Cauchy--like kernel (a bi-differential of bi-weight (1-nu,nu)) we provide a residue-formula for the entries of the Lax matrix in terms of bases of dual differentials of weights nu and 1-nu respectively. All objects are described in the most explicit terms using Theta functions. Via a sequence of ``elementary twists'', we construct sequences of Lax matrices sharing the same spectral curve and polar structure and related by conjugations by rational matrices. Particular choices of elementary twists lead to construction of sequences of Lax matrices related to finite--band recurrence relations (i.e. difference operators) sharing the same shape. Recurrences of this kind are satisfied by several types of orthogonal and biorthogonal polynomials. The relevance of formulae obtained to the study of the large degree asymptotics for these polynomials is indicated.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:07:15 GMT" }, { "version": "v2", "created": "Sun, 19 Aug 2007 16:51:39 GMT" } ]
2008-04-08T00:00:00
[ [ "Bertola", "Marco", "" ], [ "Gekhtman", "Mikael", "" ] ]
0705.0121
Jan Honolka
J. Honolka, S. Masmanidis, H.X. Tang, D.D. Awschalom, M.L. Roukes
Magnetotransport properties of strained (Ga0.95, Mn0.05)As epilayers close to the metal-insulator transition: Description using Aronov-Altshuler three-dimensional scaling theory
6 pages, 6 figures
null
10.1103/PhysRevB.75.245310
null
cond-mat.other
null
The magnitude of the anisotropic magnetoresistance (AMR) and the longitudinal resistance in compressively strained (Ga0.95, Mn0.05)As epilayers were measured for the first time down to temperatures as low as 30 mK. Below temperatures of 3K the conductivity decreases ~ T^1/3 over two orders of magnitude in temperature. The conductivity can be well described within the framework of a 3D scaling theory of Anderson's transition in the presence of spin scattering in semiconductors. It is shown that the samples are on the metallic side but very close to the metal-insulator transition (MIT). At lowest temperatures a decrease in the AMR effect is observed, which is assigned to changes in the coupling between the remaining itinerant carriers and the local Mn 5/2-spin moments.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:08:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Honolka", "J.", "" ], [ "Masmanidis", "S.", "" ], [ "Tang", "H. X.", "" ], [ "Awschalom", "D. D.", "" ], [ "Roukes", "M. L.", "" ] ]
0705.0122
Luciano Gottardi
L. Gottardi, A.de Waard, A.Usenko, G.Frossati, M.Podt, J.Flokstra, M.Bassan, V.Fafone, Y.Minenkov, A.Rocchi
Sensitivity of the spherical gravitational wave detector MiniGRAIL operating at 5 K
8 pages, 5 figures, submitted to Physical Review D
Phys.Rev.D76:102005,2007
10.1103/PhysRevD.76.102005
null
gr-qc
null
We present the performances and the strain sensitivity of the first spherical gravitational wave detector equipped with a capacitive transducer and read out by a low noise two-stage SQUID amplifier and operated at a temperature of 5 K. We characterized the detector performance in terms of thermal and electrical noise in the system output sygnal. We measured a peak strain sensitivity of $1.5\cdot 10^{-20} Hz^{-1/2}$ at 2942.9 Hz. A strain sensitivity of better than $5\cdot 10{-20}Hz{-1/2}$ has been obtained over a bandwidth of 30 Hz. We expect an improvement of more than one order of magnitude when the detector will operate at 50 mK. Our results represent the first step towards the development of an ultracryogenic omnidirectional detector sensitive to gravitational radiation in the 3kHz range.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:13:22 GMT" } ]
2008-11-26T00:00:00
[ [ "Gottardi", "L.", "" ], [ "de Waard", "A.", "" ], [ "Usenko", "A.", "" ], [ "Frossati", "G.", "" ], [ "Podt", "M.", "" ], [ "Flokstra", "J.", "" ], [ "Bassan", "M.", "" ], [ "Fafone", "V.", "" ], [ "Minenkov", "Y.", "" ], [ "Rocchi", "A.", "" ] ]
0705.0123
Mustafa Cenk Gursoy
Mustafa Cenk Gursoy
An Energy Efficiency Perspective on Training for Fading Channels
To appear in the Proc. of the 2007 IEEE International Symposium on Information Theory
null
10.1109/ISIT.2007.4557387
null
cs.IT math.IT
null
In this paper, the bit energy requirements of training-based transmission over block Rayleigh fading channels are studied. Pilot signals are employed to obtain the minimum mean-square-error (MMSE) estimate of the channel fading coefficients. Energy efficiency is analyzed in the worst case scenario where the channel estimate is assumed to be perfect and the error in the estimate is considered as another source of additive Gaussian noise. It is shown that bit energy requirement grows without bound as the snr goes to zero, and the minimum bit energy is achieved at a nonzero snr value below which one should not operate. The effect of the block length on both the minimum bit energy and the snr value at which the minimum is achieved is investigated. Flash training schemes are analyzed and shown to improve the energy efficiency in the low-snr regime. Energy efficiency analysis is also carried out when peak power constraints are imposed on pilot signals.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:27:41 GMT" } ]
2016-11-17T00:00:00
[ [ "Gursoy", "Mustafa Cenk", "" ] ]
0705.0124
Mustafa Cenk Gursoy
Mustafa Cenk Gursoy
On the Low-SNR Capacity of Phase-Shift Keying with Hard-Decision Detection
To appear in the Proc. of the 2007 IEEE International Symposium on Information Theory
null
10.1109/ISIT.2007.4557221
null
cs.IT math.IT
null
The low-snr capacity of M-ary PSK transmission over both the additive white Gaussian noise (AWGN) and fading channels is analyzed when hard-decision detection is employed at the receiver. Closed-form expressions for the first and second derivatives of the capacity at zero snr are obtained. The spectral-efficiency/bit-energy tradeoff in the low-snr regime is analyzed by finding the wideband slope and the bit energy required at zero spectral efficiency. Practical design guidelines are drawn from the information-theoretic analysis. The fading channel analysis is conducted for both coherent and noncoherent cases, and the performance penalty in the low-power regime for not knowing the channel is identified.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:38:30 GMT" } ]
2016-11-17T00:00:00
[ [ "Gursoy", "Mustafa Cenk", "" ] ]
0705.0125
Peter Cholak
Peter A. Cholak, Rod Downey, Leo Harrington
The Complexity of Orbits of Computably Enumerable Sets
To appear in the Bulletion of Symbolic Logic
null
10.1090/S0894-0347-08-00604-8
null
math.LO
null
The goal of this paper is to announce there is a single orbit of the c.e. sets with inclusion, $\E$, such that the question of membership in this orbit is $\Sigma^1_1$-complete. This result and proof have a number of nice corollaries: the Scott rank of $\E$ is $\wock +1$; not all orbits are elementarily definable; there is no arithmetic description of all orbits of $\E$; for all finite $\alpha \geq 9$, there is a properly $\Delta^0_\alpha$ orbit (from the proof). A few small corrections made in this version
[ { "version": "v1", "created": "Tue, 1 May 2007 15:53:41 GMT" }, { "version": "v2", "created": "Thu, 1 Nov 2007 13:06:09 GMT" } ]
2015-05-13T00:00:00
[ [ "Cholak", "Peter A.", "" ], [ "Downey", "Rod", "" ], [ "Harrington", "Leo", "" ] ]
0705.0126
Gaspar Bakos A
G. A. Bakos, G. Kovacs, G. Torres, D. A. Fischer, D. W. Latham, R. W. Noyes, D. D. Sasselov, T. Mazeh, A. Shporer, R. P. Butler, R. P. Stefanik, J. M. Fernandez, A. Sozzetti, A. Pal, J. Johnson, G. W. Marcy, J. Winn, B. Sipocz, J. Lazar, I. Papp, P. Sari
HD147506b: A Super-Massive Planet in an Eccentric Orbit Transiting a Bright Star
Revised version sent to ApJ
Astrophys.J.670:826-832,2007
10.1086/521866
null
astro-ph
null
We report the discovery of a massive (Mp = 9.04+/-0.50 MJup) planet transiting the bright (V = 8.7) F8 star HD 147506, with an orbital period of 5.63341+/-0.00013 days and an eccentricity of e = 0.520+/-0.010. From the transit light curve we determine that the radius of the planet is Rp = 0.982^{+0.038}_{0.105}RJup. HD 147506b (also coined HAT-P-2b) has a mass about 9 times the average mass of previously-known transiting exoplanets, and a density of rho = 11.9 g cm-3, greater than that of rocky planets like the Earth. Its mass and radius are marginally consistent with theories of structure of massive giant planets composed of pure H and He, and may require a large (~100 Earth mass) core to account for. The high eccentricity causes a 9-fold variation of insolation of the planet between peri- and apastron. Using follow-up photometry, we find that the center of transit is Tmid = 2,454,212.8559 +/- 0.0007 (HJD), and the transit duration is 0.177 +/-0.002 d.
[ { "version": "v1", "created": "Tue, 1 May 2007 15:52:57 GMT" }, { "version": "v2", "created": "Tue, 3 Jul 2007 20:31:02 GMT" } ]
2008-11-26T00:00:00
[ [ "Bakos", "G. A.", "" ], [ "Kovacs", "G.", "" ], [ "Torres", "G.", "" ], [ "Fischer", "D. A.", "" ], [ "Latham", "D. W.", "" ], [ "Noyes", "R. W.", "" ], [ "Sasselov", "D. D.", "" ], [ "Mazeh", "T.", "" ], [ "Shporer", "A.", "" ], [ "Butler", "R. P.", "" ], [ "Stefanik", "R. P.", "" ], [ "Fernandez", "J. M.", "" ], [ "Sozzetti", "A.", "" ], [ "Pal", "A.", "" ], [ "Johnson", "J.", "" ], [ "Marcy", "G. W.", "" ], [ "Winn", "J.", "" ], [ "Sipocz", "B.", "" ], [ "Lazar", "J.", "" ], [ "Papp", "I.", "" ], [ "Sari", "P.", "" ] ]
0705.0127
Dimitris Stamatellos
D. Stamatellos (1), A. P. Whitworth (1), T. Bisbas (1), S. Goodwin (2) ((1) Cardiff University, (2) Sheffield University)
Radiative transfer and the energy equation in SPH simulations of star formation
Submitted to A&A, recommended for publication
null
10.1051/0004-6361:20077373
null
astro-ph
null
We introduce and test a new and highly efficient method for treating the thermal and radiative effects influencing the energy equation in SPH simulations of star formation. The method uses the density, temperature and gravitational potential of each particle to estimate a mean optical depth, which then regulates the particle's heating and cooling. The method captures -- at minimal computational cost -- the effects of (i) the rotational and vibrational degrees of freedom of H2, H2 dissociation, H0 ionisation, (ii) opacity changes due to ice mantle melting, sublimation of dust, molecular lines, H-, bound-free and free-free processes and electron scattering; (iv) external irradiation; and (v) thermal inertia. The new algorithm reproduces the results of previous authors and/or known analytic solutions. The computational cost is comparable to a standard SPH simulation with a simple barotropic equation of state. The method is easy to implement, can be applied to both particle- and grid-based codes, and handles optical depths 0<tau<10^{11}.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:03:54 GMT" }, { "version": "v2", "created": "Thu, 2 Aug 2007 14:33:35 GMT" } ]
2009-11-13T00:00:00
[ [ "Stamatellos", "D.", "", "Cardiff University" ], [ "Whitworth", "A. P.", "", "Cardiff University" ], [ "Bisbas", "T.", "", "Cardiff University" ], [ "Goodwin", "S.", "", "Sheffield University" ] ]
0705.0128
Mustafa Cenk Gursoy
Sami Akin, Mustafa Cenk Gursoy
Training Optimization for Gauss-Markov Rayleigh Fading Channels
To appear in the Proc. of the 2007 IEEE International Conference on Communications
null
10.1109/ICC.2007.994
null
cs.IT math.IT
null
In this paper, pilot-assisted transmission over Gauss-Markov Rayleigh fading channels is considered. A simple scenario, where a single pilot signal is transmitted every T symbols and T-1 data symbols are transmitted in between the pilots, is studied. First, it is assumed that binary phase-shift keying (BPSK) modulation is employed at the transmitter. With this assumption, the training period, and data and training power allocation are jointly optimized by maximizing an achievable rate expression. Achievable rates and energy-per-bit requirements are computed using the optimal training parameters. Secondly, a capacity lower bound is obtained by considering the error in the estimate as another source of additive Gaussian noise, and the training parameters are optimized by maximizing this lower bound.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:04:39 GMT" } ]
2016-11-17T00:00:00
[ [ "Akin", "Sami", "" ], [ "Gursoy", "Mustafa Cenk", "" ] ]
0705.0129
Benjamin Piot A
B. A. Piot, D. K. Maude, M. Henini, Z. R. Wasilewski, J. A. Gupta, K. J. Friedland, R. Hey, K. H. Ploog, U. Gennser, A. Cavanna, D. Mailly, R. Airey, and G. Hill
Influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors
Published in Phys. Rev. B
Phys. Rev. B 75, 155332 (2007)
10.1103/PhysRevB.75.155332
null
cond-mat.mes-hall
null
In a recent paper [B. A. Piot et al., Phys. Rev. B 72, 245325 (2005)], we have shown that the lifting of the electron spin degeneracy in the integer quantum Hall effect at high filling factors should be interpreted as a magnetic-field-induced Stoner transition. In this work, we extend the analysis to investigate the influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors. The single-particle Zeeman energy is tuned through the application of an additional in-plane magnetic field. Both the evolution of the spin polarization of the system and the critical magnetic field for spin splitting are well described as a function of the tilt angle of the sample in the magnetic field.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:11:04 GMT" } ]
2009-11-13T00:00:00
[ [ "Piot", "B. A.", "" ], [ "Maude", "D. K.", "" ], [ "Henini", "M.", "" ], [ "Wasilewski", "Z. R.", "" ], [ "Gupta", "J. A.", "" ], [ "Friedland", "K. J.", "" ], [ "Hey", "R.", "" ], [ "Ploog", "K. H.", "" ], [ "Gennser", "U.", "" ], [ "Cavanna", "A.", "" ], [ "Mailly", "D.", "" ], [ "Airey", "R.", "" ], [ "Hill", "G.", "" ] ]
0705.0130
Mustafa Cenk Gursoy
Qingyun Wang, Mustafa Cenk Gursoy
Performance Analysis for Multichannel Reception of OOFSK Signaling
Proc. of the 2007 IEEE Wireless Communications and Networking Conference
null
10.1109/WCNC.2007.444
null
cs.IT math.IT
null
In this paper, the error performance of on-off frequency shift keying (OOFSK) modulation over fading channels is analyzed when the receiver is equipped with multiple antennas. The analysis is conducted in two cases: the coherent scenario where the fading is perfectly known at the receiver, and the noncoherent scenario where neither the receiver nor the transmitter knows the fading coefficients. For both cases, the maximum a posteriori probability (MAP) detection rule is derived and analytical probability of error expressions are obtained. The effect of fading correlation among the receiver antennas is also studied. Simulation results indicate that for sufficiently low duty cycle values, lower probability of error values with respect to FSK signaling are achieved. Equivalently, when compared to FSK modulation, OOFSK with low duty cycle requires less energy to achieve the same probability of error, which renders this modulation a more energy efficient transmission technique.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:11:28 GMT" } ]
2016-11-17T00:00:00
[ [ "Wang", "Qingyun", "" ], [ "Gursoy", "Mustafa Cenk", "" ] ]
0705.0131
Christof Sparber
Johannes Giannoulis, Alexander Mielke, Christof Sparber
Interaction of modulated pulses in the nonlinear Schroedinger equation with periodic potential
null
null
null
null
math.AP math-ph math.MP nlin.SI
null
We consider a cubic nonlinear Schroedinger equation with periodic potential. In a semiclassical scaling the nonlinear interaction of modulated pulses concentrated in one or several Bloch bands is studied. The notion of closed mode systems is introduced which allows for the rigorous derivation of a finite system of amplitude equations describing the macroscopic dynamics of these pulses.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:14:04 GMT" } ]
2007-07-18T00:00:00
[ [ "Giannoulis", "Johannes", "" ], [ "Mielke", "Alexander", "" ], [ "Sparber", "Christof", "" ] ]
0705.0132
Mustafa Cenk Gursoy
Mustafa Cenk Gursoy
Error Probability Analysis of Peaky Signaling over Fading Channels
Proc. of the 40th Annual Asilomar Conference on Signals, Systems, and Computers, 2006
null
null
null
cs.IT math.IT
null
In this paper, the performance of signaling strategies with high peak-to-average power ratio is analyzed in both coherent and noncoherent fading channels. Two recently proposed modulation schemes, namely on-off binary phase-shift keying and on-off quaternary phase-shift keying, are considered. For these modulation formats, the optimal decision rules used at the detector are identified and analytical expressions for the error probabilities are obtained. Numerical techniques are employed to compute the error probabilities. It is concluded that increasing the peakedness of the signals results in reduced error rates for a given power level and hence improve the energy efficiency.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:20:05 GMT" } ]
2007-07-13T00:00:00
[ [ "Gursoy", "Mustafa Cenk", "" ] ]
0705.0133
S. I. Kruglov
S. I. Kruglov
Effective Lagrangian at Cubic Order in Electromagnetic Fields and Vacuum Birefringence
10 pages, no figures, added note, published version
Phys.Lett.B652:146-149,2007
10.1016/j.physletb.2007.06.069
null
hep-ph astro-ph hep-th
null
The effective Lagrangian of electromagnetic fields at the cubic order in field strength has been considered. This generalized Lagrangian is motivated by electrodynamics on non-commutative spaces. We find the canonical and symmetrical energy-momentum tensors and show that they possess non-zero traces. The propagation of a linearly polarized laser beam in the external transverse magnetic field is investigated. We evaluate the induced ellipticity which allows us to obtain a constraint on parameters introduced from the PVLAS experimental data.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:29:14 GMT" }, { "version": "v2", "created": "Sat, 26 May 2007 17:03:53 GMT" }, { "version": "v3", "created": "Thu, 9 Aug 2007 15:56:32 GMT" } ]
2008-11-26T00:00:00
[ [ "Kruglov", "S. I.", "" ] ]
0705.0134
Roman Schubert
Roman Schubert
Semiclassical wave propagation for large times
40 pages, 1 figure, This paper has been withdrawn by the author due to a gap in the proof of the dispersive estimates
null
null
null
math-ph math.AP math.MP nlin.CD
null
We study solutions of the time dependent Schr\"odinger equation on Riemannian manifolds with oscillatory initial conditions given by Lagrangian states. Semiclassical approximations describe these solutions for small h (where h is the semiclassical parameter), but their accuracy for large times is in general only understood up to the Ehrenfest time T ~ ln(1/h), and the most difficult case is the one where the underlying classical system is chaotic. We show that on surfaces of constant negative curvature semiclassical approximations remain accurate for times at least up to T ~ h^(-1/2) in the case that the Lagrangian state is associated with an unstable manifold of the geodesic flow.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:29:45 GMT" }, { "version": "v2", "created": "Sat, 17 Dec 2011 13:55:59 GMT" } ]
2011-12-20T00:00:00
[ [ "Schubert", "Roman", "" ] ]
0705.0135
Davar Khoshnevisan
Davar Khoshnevisan and Yimin Xiao
Packing-Dimension Profiles and Fractional Brownian Motion
null
null
10.1017/S0305004108001394
null
math.PR math.CA
null
In order to compute the packing dimension of orthogonal projections Falconer and Howroyd (1997) introduced a family of packing dimension profiles ${\rm Dim}_s$ that are parametrized by real numbers $s>0$. Subsequently, Howroyd (2001) introduced alternate $s$-dimensional packing dimension profiles $\hbox{${\rm P}$-$\dim$}_s$ and proved, among many other things, that $\hbox{${\rm P}$-$\dim$}_s E={\rm Dim}_s E$ for all integers $s>0$ and all analytic sets $E\subseteq\R^N$. The goal of this article is to prove that $\hbox{${\rm P}$-$\dim$}_s E={\rm Dim}_s E$ for all real numbers $s>0$ and analytic sets $E\subseteq\R^N$. This answers a question of Howroyd (2001, p. 159). Our proof hinges on a new property of fractional Brownian motion.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:30:48 GMT" } ]
2019-05-01T00:00:00
[ [ "Khoshnevisan", "Davar", "" ], [ "Xiao", "Yimin", "" ] ]
0705.0136
Peter Koval
Peter Koval, Stephan Fritzsche and Andrey Surzhykov
Angular distribution studies on the two-photon ionization of hydrogen-like ions: Relativistic description
16 pages, 4 figures, published in J Phys B
2004 J. Phys. B: At. Mol. Opt. Phys. 37, 375-388
10.1088/0953-4075/37/2/006
null
physics.atom-ph
null
The angular distribution of the emitted electrons, following the two-photon ionization of the hydrogen-like ions, is studied within the framework of second order perturbation theory and the Dirac equation. Using a density matrix approach, we have investigated the effects which arise from the polarization of the incoming light as well as from the higher multipoles in the expansion of the electron--photon interaction. For medium- and high-Z ions, in particular, the non-dipole contributions give rise to a significant change in the angular distribution of the emitted electrons, if compared with the electric-dipole approximation. This includes a strong forward emission while, in dipole approxmation, the electron emission always occurs symmetric with respect to the plane which is perpendicular to the photon beam. Detailed computations for the dependence of the photoelectron angular distributions on the polarization of the incident light are carried out for the ionization of H, Xe$^{53+}$, and U$^{91+}$ (hydrogen-like) ions.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:32:32 GMT" } ]
2007-05-23T00:00:00
[ [ "Koval", "Peter", "" ], [ "Fritzsche", "Stephan", "" ], [ "Surzhykov", "Andrey", "" ] ]
0705.0137
E. V. Sampathkumaran
Niharika Mohapatra, E.V. Sampathkumaran
Effect of a small disruption of the Ca site on the geometrically frustrated magnetic behavior of Ca3CoRhO6
10 pages including 5 figures
null
10.1016/j.ssc.2007.05.005
null
cond-mat.str-el
null
The compound, Ca3CoRhO6, containing magnetic Co-Rh chains intervened by Ca ions, has been known to be one of the few exhibiting partially disordered antiferromagnetic structure (PDA) due to geometrical frustration. Here, we report the influence of partial replacement of Ca by Y on the magnetic anomalies by investigating the solid solution, Ca(3-x)Y(x)CoRhO6 by bulk measurements. There are profound changes in the magnetic behavior, the most notable one being that the features attributable to spin-chain magnetism and PDA structure get suppressed dramatically by a small replacement of Ca by Y (x= 0.15), despite the fact that the magnetic chain is not disrupted. This finding suggests that this compound is on the verge of PDA-structural-instability.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:42:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Mohapatra", "Niharika", "" ], [ "Sampathkumaran", "E. V.", "" ] ]
0705.0138
R. Dean Astumian
R. Dean Astumian
Symmetry Relations for Trajectories of a Brownian Motor
null
null
10.1103/PhysRevE.76.020102
null
cond-mat.stat-mech cond-mat.soft
null
A Brownian Motor is a nanoscale or molecular device that combines the effects of thermal noise, spatial or temporal asymmetry, and directionless input energy to drive directed motion. Because of the input energy, Brownian motors function away from thermodynamic equilibrium and concepts such as linear response theory, fluctuation dissipation relations, and detailed balance do not apply. The {\em generalized} fluctuation-dissipation relation, however, states that even under strongly thermodynamically non-equilibrium conditions the ratio of the probability of a transition to the probability of the time-reverse of that transition is the exponent of the change in the internal energy of the system due to the transition. Here, we derive an extension of the generalized fluctuation dissipation theorem for a Brownian motor for the ratio between the probability for the motor to take a forward step and the probability to take a backward step.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:47:42 GMT" }, { "version": "v2", "created": "Tue, 15 May 2007 17:13:10 GMT" } ]
2009-11-13T00:00:00
[ [ "Astumian", "R. Dean", "" ] ]
0705.0139
Mark Hertzberg
M. P. Hertzberg (MIT), R. L. Jaffe (MIT), M. Kardar (MIT), and A. Scardicchio (Princeton)
Casimir Forces in a Piston Geometry at Zero and Finite Temperatures
Updated to match version published in PRD, 13 pages, 5 figures
Phys.Rev.D76:045016,2007
10.1103/PhysRevD.76.045016
MIT-CTP-3703
quant-ph cond-mat.stat-mech hep-th
null
We study Casimir forces on the partition in a closed box (piston) with perfect metallic boundary conditions. Related closed geometries have generated interest as candidates for a repulsive force. By using an optical path expansion we solve exactly the case of a piston with a rectangular cross section, and find that the force always attracts the partition to the nearest base. For arbitrary cross sections, we can use an expansion for the density of states to compute the force in the limit of small height to width ratios. The corrections to the force between parallel plates are found to have interesting dependence on the shape of the cross section. Finally, for temperatures in the range of experimental interest we compute finite temperature corrections to the force (again assuming perfect boundaries).
[ { "version": "v1", "created": "Tue, 1 May 2007 16:48:58 GMT" }, { "version": "v2", "created": "Sun, 18 Nov 2007 01:44:53 GMT" } ]
2008-11-26T00:00:00
[ [ "Hertzberg", "M. P.", "", "MIT" ], [ "Jaffe", "R. L.", "", "MIT" ], [ "Kardar", "M.", "", "MIT" ], [ "Scardicchio", "A.", "", "Princeton" ] ]
0705.0140
Davar Khoshnevisan
Davar Khoshnevisan
Dynamical percolation on general trees
24 pages; to appear in Probability Theory and Related Fields
null
10.1007/s00440-007-0061-6
null
math.PR
null
H\"aggstr\"om, Peres, and Steif (1997) have introduced a dynamical version of percolation on a graph $G$. When $G$ is a tree they derived a necessary and sufficient condition for percolation to exist at some time $t$. In the case that $G$ is a spherically symmetric tree, H\"aggstr\"om, Peres, and Steif (1997) derived a necessary and sufficient condition for percolation to exist at some time $t$ in a given target set $D$. The main result of the present paper is a necessary and sufficient condition for the existence of percolation, at some time $t\in D$, in the case that the underlying tree is not necessary spherically symmetric. This answers a question of Yuval Peres (personal communication). We present also a formula for the Hausdorff dimension of the set of exceptional times of percolation.
[ { "version": "v1", "created": "Tue, 1 May 2007 16:57:47 GMT" } ]
2007-05-23T00:00:00
[ [ "Khoshnevisan", "Davar", "" ] ]
0705.0141
Kevin Pearson
K. J. Pearson
Are Superhumps Good Measures of the Mass Ratio for AM CVn Systems?
7 pages, 2 tables, to appear in Monthly Notices of the Royal Astronomical Society
Mon.Not.Roy.Astron.Soc.379:183-189,2007
10.1111/j.1365-2966.2007.11932.x
null
astro-ph
null
We extend recent work that included the effect of pressure forces to derive the precession rate of eccentric accretion discs in cataclysmic variables to the case of double degenerate systems. We find that the logical scaling of the pressure force in such systems results in predictions of unrealistically high primary masses. Using the prototype AM CVn as a calibrator for the magnitude of the effect, we find that there is no scaling that applies consistently to all the systems in the class. We discuss the reasons for the lack of a superhump period to mass ratio relationship analogous to that known for SU UMa systems and suggest that this is because these secondaries do not have a single valued mass-radius relationship. We highlight the unreliability of mass-ratios derived by applying the SU UMa expression to the AM CVn binaries.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:19:53 GMT" } ]
2009-06-23T00:00:00
[ [ "Pearson", "K. J.", "" ] ]
0705.0142
Krzysztof Stanek
Krzysztof Zbigniew Stanek
A Modest Proposal for the Astronomical Community
7 pages, no figures, one link;
null
null
null
astro-ph
null
Inspired by a recent astro-ph posting, I propose a creation of an Alternative History astro-ph archive (althistastro-ph). Such an archive would serve as a final resting place for the various telescope (and possibly other) proposals that were not successful. As we all know, from both submitting proposals and also from serving on various time allocation committees, many excellent proposals ``do not make it''. Creating such an AltHist archive would serve many goals, including venting the frustration of the authors and also providing possible amusement for the readers. These are worthy goals, but they alone would not warrant creating such an archive. The truly useful role of AltHistAstro-ph archive would be to match astronomers with unappreciated ideas with other astronomers with underutilized resources, hopefully leading in some cases to resurrection of old proposals and resulting publications in the regular astro-ph archive. Given the possible danger of a low signal-to-noise and possible confusion, a creation of a separate archive seems like a good idea, although it should be noted that low signal-to-noise is achieved on astro-ph quite often already. Finally, I include my own excellent, but rejected (twice), HST proposal, as an example of a potential AltHistAstro-ph posting.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:25:38 GMT" } ]
2007-05-23T00:00:00
[ [ "Stanek", "Krzysztof Zbigniew", "" ] ]
0705.0143
J. Antonio Garcia Zenteno
J. Antonio Garcia
DSR and Canonical Transformations: A Comment on a ``A Lagrangian for DSR particle and the role of noncommutativity''
3 pages. Accepted in PRD. v2 Fixed typos, reference added, version for PRD
Phys.Rev.D76:048501,2007
10.1103/PhysRevD.76.048501
null
hep-th gr-qc math-ph math.MP
null
The aim of this comment is to call to the attention of DSR readers a basic fact. The introduction of noncommutative structures in problems like the one addressed in [1] is not necessary for the understanding of DSR physics. It can be described just as the relativistic free particle problem in a different parametrization.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:17:27 GMT" }, { "version": "v2", "created": "Sat, 18 Aug 2007 02:26:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Garcia", "J. Antonio", "" ] ]
0705.0144
Micheline Vigue-Poirrier
Micheline Vigu\'e-Poirrier (Paris 13)
Formality of function spaces
8 pages
null
null
null
math.AT
null
Let $X$ be a nilpotent space such that there exists $p\geq 1$ with $H^p(X,\mathbb Q) \ne 0$ and $H^n(X,\mathbb Q)=0$ if $n>p$. Let $Y$ be a m-connected space with $m\geq p+1$ and $H^*(Y,\mathbb Q)$ is finitely generated as algebra. We assume that $X$ is formal and there exists $p$ odd such that $H^p(X,\mathbb Q) \ne 0$. We prove that if the space $\mathcal F(X,Y)$ of continuous maps from $X$ to $Y$ is formal, then $Y$ has the rational homotopy type of a product of Eilenberg Mac Lane spaces. At the opposite, we exhibit an example of a formal space $\mathcal F(S^2,Y)$ where $Y$ is not rationally equivalent to a product of Eilenberg Mac Lane spaces.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:18:32 GMT" } ]
2007-05-23T00:00:00
[ [ "Vigué-Poirrier", "Micheline", "", "Paris 13" ] ]
0705.0145
Mao-Chang Liang
Mao-Chang Liang, Yuk L. Yung, and Donald E. Shemansky
Photolytically generated aerosols in the mesosphere and thermosphere of Titan
A typo in Table 1 was made in the previous version. The corrected tholin abundance is 4.6x10^11. ApJL in press. Will be published on June 1st, or May 21 online
null
10.1086/518785
null
astro-ph
null
Analysis of the Cassini Ultraviolet Imaging Spectrometer (UVIS) stellar and solar occultations at Titan to date include 12 species: N$_{2}$ (nitrogen), CH$_{4}$ (methane), C$_{2}$H$_{2}$ (acetylene), C$_{2}$H$_{4}$ (ethylene), C$_{2}$H$_{6}$ (ethane), C$_{4}$H$_{2}$ (diacetylene), C$_{6}$H$_{6}$ (benzene), C$_{6}$N$_{2}$ (dicyanodiacetylene), C$_{2}$N$_{2}$ (cyanogen), HCN (hydrogen cyanide), HC$_{3}$N (cyanoacetylene), and aerosols distinguished by a structureless continuum extinction (absorption plus scattering) of photons in the EUV. The introduction of aerosol particles, retaining the same refractive index properties as tholin with radius $\sim$125 \AA and using Mie theory, provides a satisfactory fit to the spectra. The derived vertical profile of aerosol density shows distinct structure, implying a reactive generation process reaching altitudes more than 1000 km above the surface. A photochemical model presented here provides a reference basis for examining the chemical and physical processes leading to the distinctive atmospheric opacity at Titan. We find that dicyanodiacetylene is condensable at $\sim$650 km, where the atmospheric temperature minimum is located. This species is the simplest molecule identified to be condensable. Observations are needed to confirm the existence and production rates of dicyanodiacetylene.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:22:23 GMT" }, { "version": "v2", "created": "Thu, 3 May 2007 23:03:25 GMT" } ]
2009-11-13T00:00:00
[ [ "Liang", "Mao-Chang", "" ], [ "Yung", "Yuk L.", "" ], [ "Shemansky", "Donald E.", "" ] ]
0705.0146
Lucas Labadie
L. Labadie (MPIA), E. Le Coarer (LAOG), R. Maurand (LAOG), P. Labeye (CEA Leti), P. Kern (LAOG), B. Arezki (LAOG), J.-E. Broquin (LAOG)
Mid-infrared laser light nulling experiment using single-mode conductive waveguides
Accepted in A&A, 7 pages, 5 figures
null
10.1051/0004-6361:20067005
null
astro-ph
null
Aims: In the context of space interferometry missions devoted to the search of exo-Earths, this paper investigates the capabilities of new single mode conductive waveguides at providing modal filtering in an infrared and monochromatic nulling experiment; Methods: A Michelson laser interferometer with a co-axial beam combination scheme at 10.6 microns is used. After introducing a Pi phase shift using a translating mirror, dynamic and static measurements of the nulling ratio are performed in the two cases where modal filtering is implemented and suppressed. No additional active control of the wavefront errors is involved. Results: We achieve on average a statistical nulling ratio of 2.5e-4 with a 1-sigma upper limit of 6e-4, while a best null of 5.6e-5 is obtained in static mode. At the moment, the impact of external vibrations limits our ability to maintain the null to 10 to 20 seconds.; Conclusions: A positive effect of SM conductive waveguide on modal filtering has been observed in this study. Further improvement of the null should be possible with proper mechanical isolation of the setup.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:28:16 GMT" } ]
2009-11-13T00:00:00
[ [ "Labadie", "L.", "", "MPIA" ], [ "Coarer", "E. Le", "", "LAOG" ], [ "Maurand", "R.", "", "LAOG" ], [ "Labeye", "P.", "", "CEA Leti" ], [ "Kern", "P.", "", "LAOG" ], [ "Arezki", "B.", "", "LAOG" ], [ "Broquin", "J. -E.", "", "LAOG" ] ]
0705.0147
R. Srikanth
R. Srikanth and Srikanth Hebri
G\"odel Incompleteness and the Black Hole Information Paradox
14 pages, 2 figures; revised according to journal requirements
Quantum Information Processing 7, 291 (2008)
10.1007/s11128-008-0089-2
null
quant-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Semiclassical reasoning suggests that the process by which an object collapses into a black hole and then evaporates by emitting Hawking radiation may destroy information, a problem often referred to as the black hole information paradox. Further, there seems to be no unique prediction of where the information about the collapsing body is localized. We propose that the latter aspect of the paradox may be a manifestation of an inconsistent self-reference in the semiclassical theory of black hole evolution. This suggests the inadequacy of the semiclassical approach or, at worst, that standard quantum mechanics and general relavity are fundamentally incompatible. One option for the resolution for the paradox in the localization is to identify the G\"odel-like incompleteness that corresponds to an imposition of consistency, and introduce possibly new physics that supplies this incompleteness. Another option is to modify the theory in such a way as to prohibit self-reference. We discuss various possible scenarios to implement these options, including eternally collapsing objects, black hole remnants, black hole final states, and simple variants of semiclassical quantum gravity.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:57:11 GMT" }, { "version": "v2", "created": "Tue, 6 Nov 2007 15:55:08 GMT" }, { "version": "v3", "created": "Mon, 22 Dec 2008 17:34:08 GMT" } ]
2008-12-22T00:00:00
[ [ "Srikanth", "R.", "" ], [ "Hebri", "Srikanth", "" ] ]
0705.0148
Sumiyoshi Abe
Sumiyoshi Abe (1), Christian Beck (2), and E. G. D. Cohen (3)((1) Mie University, Japan and ISMANS, France, (2) Queen Mary, University of London, UK, (3) The Rockefeller University, USA)
Superstatistics, thermodynamics, and fluctuations
16 pages, no figures. The title changed, some explanations and references added. Accepted for publication in Phys. Rev. E
null
10.1103/PhysRevE.76.031102
null
cond-mat.stat-mech cond-mat.dis-nn
null
A thermodynamic-like formalism is developed for superstatistical systems based on conditional entropies. This theory takes into account large-scale variations of intensive variables of systems in nonequilibrium stationary states. Ordinary thermodynamics is recovered as a special case of the present theory, and corrections to it can be systematically evaluated. A generalization of Einstein's relation for fluctuations is presented using a maximum entropy condition.
[ { "version": "v1", "created": "Tue, 1 May 2007 17:58:40 GMT" }, { "version": "v2", "created": "Fri, 20 Jul 2007 14:26:06 GMT" } ]
2009-11-13T00:00:00
[ [ "Abe", "Sumiyoshi", "" ], [ "Beck", "Christian", "" ], [ "Cohen", "E. G. D.", "" ] ]
0705.0149
Sergey Fedosov
S. N. Fedosov, A. F. Butenko, and A. E. Sergeeva
Two components of depolarization currents in PVDF caused by relaxation of homo- and heterocharge
6 pages, 3 figures. Submitted to phys. stat. sol. (a)
null
null
null
cond-mat.mtrl-sci
null
The procedure has been developed for extracting homocharge and heterocharge currents from experimentally measured thermally stimulated depolarization currents of corona poled PVDF. Application of different depolarization modes supplemented with the isothermal currents allowed to obtain such parameters of relaxation processes, as activation energies, characteristic frequencies and time constants.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:07:59 GMT" } ]
2007-05-23T00:00:00
[ [ "Fedosov", "S. N.", "" ], [ "Butenko", "A. F.", "" ], [ "Sergeeva", "A. E.", "" ] ]
0705.0150
Myung-Sin Song
Palle E. T. Jorgensen, Myung-Sin Song
Comparison of Discrete and Continuous Wavelet Transforms
22 pages, Springer Encyclopedia of Complexity and Systems Science, the full version with figures is available at http://www.siue.edu/~msong/Research/ency.pdf
null
null
null
cs.CE
null
In this paper we outline several points of view on the interplay between discrete and continuous wavelet transforms; stressing both pure and applied aspects of both. We outline some new links between the two transform technologies based on the theory of representations of generators and relations. By this we mean a finite system of generators which are represented by operators in Hilbert space. We further outline how these representations yield sub-band filter banks for signal and image processing algorithms.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:24:52 GMT" }, { "version": "v2", "created": "Fri, 24 Aug 2007 17:53:30 GMT" } ]
2011-11-09T00:00:00
[ [ "Jorgensen", "Palle E. T.", "" ], [ "Song", "Myung-Sin", "" ] ]
0705.0151
Hooman Davoudiasl
Hooman Davoudiasl and Amarjit Soni
Strong CP, Up-Quark Mass, and the Randall-Sundrum Microscope
7 pages. New discussions and references added. Main previous conclusions unchanged
Phys.Rev.D76:095015,2007
10.1103/PhysRevD.76.095015
BNL-HET-07/6
hep-ph
null
In the Randall-Sundrum model, setting the ratio of up and down quark masses $m_u/m_d << 1$, relevant to the strong CP problem, does not require chiral symmetry or fine-tuning, due to exponential bulk fermion profiles. We point out that such geometric suppression of the mass of a fermion magnifies the masses of its corresponding Kaluza-Klein (KK) states. In this sense, these KK states act as "microscopes" for probing light quark and lepton masses. In simple realizations, this hypothesis can be testable at future colliders, like the LHC, by measuring the spectrum of level-1 KK fermions. The microscope can then provide an experimental test for the vanishing of $m_u$ in the ultraviolet, independently of non-perturbative determinations, by lattice simulations or other means, at hadronic scales. We also briefly comment on application of our microscope idea to other fermions, such as the electron and neutrinos.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:25:20 GMT" }, { "version": "v2", "created": "Mon, 27 Aug 2007 22:54:05 GMT" } ]
2008-11-26T00:00:00
[ [ "Davoudiasl", "Hooman", "" ], [ "Soni", "Amarjit", "" ] ]
0705.0152
Dietrich Belitz
D. Belitz, T. R. Kirkpatrick and Ronojoy Saha
Criticality in inhomogeneous magnetic systems: Application to quantum ferromagnets
4pp, 4 eps figs, contains additional information compared to PRL version. PRl, in press
Phys. Rev. Lett. 99, 147203 (2007)
10.1103/PhysRevLett.99.147203
null
cond-mat.stat-mech cond-mat.str-el
null
We consider a $\phi^4$-theory with a position-dependent distance from the critical point. One realization of this model is a classical ferromagnet subject to non-uniform mechanical stress. We find a sharp phase transition where the envelope of the local magnetization vanishes uniformly. The first-order transition in a quantum ferromagnet also remains sharp. The universal mechanism leading to a tricritical point in an itinerant quantum ferromagnet is suppressed, and in principle one can recover a quantum critical point with mean-field exponents. Observable consequences of these results are discussed.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:26:52 GMT" }, { "version": "v2", "created": "Fri, 24 Aug 2007 17:22:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Belitz", "D.", "" ], [ "Kirkpatrick", "T. R.", "" ], [ "Saha", "Ronojoy", "" ] ]
0705.0153
Richard Woodard
E. O. Kahya and R. P. Woodard (University of Florida)
A Generic Test of Modified Gravity Models which Emulate Dark Matter
4 pages, uses RevTex, no figures
Phys.Lett.B652:213-216,2007
10.1016/j.physletb.2007.07.029
UFIFT-QG-07-01
astro-ph gr-qc hep-ph
null
We propose a generic test for models in which gravity is modified to do away with dark matter. These models tend to have gravitons couple to a different metric than ordinary matter. A strong test of such models comes from comparing the arrival time of the gravitational wave pulse from a cosmological event such as a supernova with the arrival times of the associated pulses of neutrinos and photons. For SN 1987a we show that the gravity wave would have arrived 5.3 days after the neutrino pulse.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:33:22 GMT" } ]
2009-06-23T00:00:00
[ [ "Kahya", "E. O.", "", "University of Florida" ], [ "Woodard", "R. P.", "", "University of Florida" ] ]
0705.0154
Edward L. Fitzpatrick
E.L. Fitzpatrick and D. Massa
An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
To appear in the Astrophysical Journal, Part 1, July 1, 2007. Figures and Tables which will appear only in the electronic version of the Journal can be obtained via anonymous ftp from ftp://ftp.astronomy.villanova.edu . After logging in, change directories to "fitz/FMV_EXTINCTION". A README file describes the various files present in the directory
Astrophys.J.663:320-341,2007
10.1086/518158
null
astro-ph
null
We study the IR-through-UV interstellar extinction curves towards 328 Galactic B and late-O stars. We use a new technique which employs stellar atmosphere models in lieu of unreddened "standard" stars. This technique is capable of virtually eliminating spectral mismatch errors in the curves. It also allows a quantitative assessment of the errors and enables a rigorous testing of the significance of relationships between various curve parameters, regardless of whether their uncertainties are correlated. Analysis of the curves gives the following results: (1) In accord with our previous findings, the central position of the 2175 A extinction bump is mildly variable, its width is highly variable, and the two variations are unrelated. (2) Strong correlations are found among some extinction properties within the UV region, and within the IR region. (3) With the exception of a few curves with extreme (i.e., large) values of R(V), the UV and IR portions of Galactic extinction curves are not correlated with each other. (4) The large sightline-to-sightline variation seen in our sample implies that any average Galactic extinction curve will always reflect the biases of its parent sample. (5) The use of an average curve to deredden a spectral energy distribution (SED) will result in significant errors, and a realistic error budget for the dereddened SED must include the observed variance of Galactic curves. While the observed large sightline-to-sightline variations, and the lack of correlation among the various features of the curves, make it difficult to meaningfully characterize average extinction properties, they demonstrate that extinction curves respond sensitively to local conditions. Thus, each curve contains potentially unique information about the grains along its sightline.
[ { "version": "v1", "created": "Tue, 1 May 2007 18:37:10 GMT" } ]
2009-06-23T00:00:00
[ [ "Fitzpatrick", "E. L.", "" ], [ "Massa", "D.", "" ] ]
0705.0155
Frederick K. Lamb
Frederick K. Lamb and Stratos Boutloukos
Accreting Neutron Stars in Low-Mass X-Ray Binary Systems
22 pages, 7 figures, updated list of sources and references, to appear in "Short-period Binary Stars: Observation, Analyses, and Results", eds. E.F. Milone, D.A. Leahy, and D. Hobill (Dordrecht: Springer, http://www.springerlink.com)
null
10.1007/978-1-4020-6544-6_5
null
astro-ph
null
Using the Rossi X-ray Timing Explorer (RossiXTE), astronomers have discovered that disk-accreting neutron stars with weak magnetic fields produce three distinct types of high-frequency X-ray oscillations. These oscillations are powered by release of the binding energy of matter falling into the strong gravitational field of the star or by the sudden nuclear burning of matter that has accumulated in the outermost layers of the star. The frequencies of the oscillations reflect the orbital frequencies of gas deep in the gravitational field of the star and/or the spin frequency of the star. These oscillations can therefore be used to explore fundamental physics, such as strong-field gravity and the properties of matter under extreme conditions, and important astrophysical questions, such as the formation and evolution of millisecond pulsars. Observations using RossiXTE have shown that some two dozen neutron stars in low-mass X-ray binary systems have the spin rates and magnetic fields required to become millisecond radio-emitting pulsars when accretion ceases, but that few have spin rates above about 600 Hz. The properties of these stars show that the paucity of spin rates greater than 600 Hz is due in part to the magnetic braking component of the accretion torque and to the limited amount of angular momentum that can be accreted in such systems. Further study will show whether braking by gravitational radiation is also a factor. Analysis of the kilohertz oscillations has provided the first evidence for the existence of the innermost stable circular orbit around dense relativistic stars that is predicted by strong-field general relativity. It has also greatly narrowed the possible descriptions of ultradense matter.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:15:06 GMT" }, { "version": "v2", "created": "Thu, 28 Jun 2007 05:52:47 GMT" } ]
2015-11-11T00:00:00
[ [ "Lamb", "Frederick K.", "" ], [ "Boutloukos", "Stratos", "" ] ]
0705.0156
Cristina Bena
Cristina Bena, Ines Safi
Emission and absorption noise in the fractional quantum Hall effect
26 pages, 11 figures
null
10.1103/PhysRevB.76.125317
null
cond-mat.str-el cond-mat.mes-hall
null
We compute the high-frequency emission and absorption noise in a fractional quantum Hall effect (FQHE) sample at arbitrary temperature. We model the edges of the FQHE as chiral Luttinger liquids (LL) and we use the non-equilibrium perturbative Keldysh formalism. We find that the non-symmetrized high frequency noise contains important signatures of the electron-electron interactions that can be used to test the Luttinger liquid physics, not only in FQHE edge states, but possibly also in other one-dimensional systems such as carbon nanotubes. In particular we find that the emission and absorption components of the excess noise (defined as the difference between the noise at finite voltage and at zero voltage) are different in an interacting system, as opposed to the non-interacting case when they are identical. We study the resonance features which appear in the noise at the Josephson frequency (proportional to the applied voltage), and we also analyze the effect of the distance between the measurement point and the backscattering site. Most of our analysis is performed in the weak backscattering limit, but we also compute and discuss briefly the high-frequency noise in the tunneling regime.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:27:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Bena", "Cristina", "" ], [ "Safi", "Ines", "" ] ]
0705.0157
Mattias Marklund
M. Marklund, L. Stenflo, P. K. Shukla
Magnetosonic solitons in a dusty plasma slab
7 pages, 6 figures
null
10.1017/S0022377807006964
null
physics.plasm-ph
null
The existence of magnetosonic solitons in dusty plasmas is investigated. The nonlinear magnetohydrodynamic equations for a warm dusty magnetoplasma are thus derived. A solution of the nonlinear equations is presented. It is shown that, due to the presence of dust, static structures are allowed. This is in sharp contrast to the formation of the so called shocklets in usual magnetoplasmas. A comparatively small number of dust particles can thus drastically alter the behavior of the nonlinear structures in magnetized plasmas.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:28:56 GMT" }, { "version": "v2", "created": "Tue, 31 Jul 2007 20:06:55 GMT" } ]
2015-05-13T00:00:00
[ [ "Marklund", "M.", "" ], [ "Stenflo", "L.", "" ], [ "Shukla", "P. K.", "" ] ]
0705.0158
Laszlo Kish
Laszlo B. Kish, Robert Mingesz, Zoltan gingl
Thermal noise informatics: Totally secure communication via a wire; Zero-power communication; and Thermal noise driven computing
Plenary Talk at the 4th International Symposium on Fluctuations and Noise, Florence, Italy, May 23, 2007. Results are featured in New Scientist (technology section), May 23, 2007, by Jason Palmer
null
10.1117/12.727078
null
physics.gen-ph physics.data-an
null
Very recently, it has been shown that thermal noise and its artificial versions (Johnson-like noises) can be utilized as an information carrier with peculiar properties therefore it may be proper to call this topic Thermal Noise Informatics. Zero Power (Stealth) Communication, Thermal Noise Driven Computing, and Totally Secure Classical Communication are relevant examples. In this paper, while we will briefly describe the first and the second subjects, we shall focus on the third subject, the secure classical communication via wire. This way of secure telecommunication utilizes the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The communicator is unconditionally secure at the conceptual (circuit theoretical) level and this property is (so far) unique in communication systems based on classical physics. The communicator is superior to quantum alternatives in all known aspects, except the need of using a wire. In the idealized system, the eavesdropper can extract zero bit of information without getting uncovered. The scheme is naturally protected against the man-in-the-middle attack. The communication can take place also via currently used power lines or phone (wire) lines and it is not only a point-to-point communication like quantum channels but network-ready. Tests have been carried out on a model-line with ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance. This simple device has single-wire secure key generation/sharing rates of 0.1, 1, 10, and 100 bit/second for copper wires with diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity).
[ { "version": "v1", "created": "Tue, 1 May 2007 19:38:58 GMT" }, { "version": "v2", "created": "Wed, 30 May 2007 13:13:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Kish", "Laszlo B.", "" ], [ "Mingesz", "Robert", "" ], [ "gingl", "Zoltan", "" ] ]
0705.0159
John Hammersley
John Hammersley
Numerical metric extraction in AdS/CFT
38 pages, 16 figures; v2 reference added, minor corrections; v3 some changes to method and appendices, new sections added on validating the solutions and extensions to less symmetric cases, version accepted for publication in General Relativity and Gravitation
Gen.Rel.Grav.40:1619-1652,2008
10.1007/s10714-007-0564-6
null
hep-th gr-qc
null
An iterative method for recovering the bulk information in asymptotically AdS spacetimes is presented. We consider zero energy spacelike geodesics and their relation to the entanglement entropy in three dimensions to determine the metric in certain symmetric cases. A number of comparisons are made with an alternative extraction method presented in arXiv:hep-th/0609202, and the two methods are then combined to allow metric recovery in the most general type of static, spherically symmetric setups. We conclude by extracting the mass and density profiles for a toy model example of a gas of radiation in (2+1)-dimensional AdS.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:43:21 GMT" }, { "version": "v2", "created": "Fri, 25 May 2007 09:12:57 GMT" }, { "version": "v3", "created": "Fri, 23 Nov 2007 17:06:59 GMT" } ]
2008-11-26T00:00:00
[ [ "Hammersley", "John", "" ] ]
0705.0160
Laszlo Kish
L.B. Kish, G. Schmera, Ch. Kwan, J. Smulko, P. Heszler, C.-G. Granqvist
Fluctuation-enhanced sensing
Keynote Talk at SPIE's 4th international symposium on Fluctuations and Noise, Conference Noise and Fluctuations in Circuits, Devices and Materials, Florence, Italy, May 20-24, 2007
null
10.1117/12.726838
null
physics.gen-ph physics.data-an
null
We present a short survey on fluctuation-enhanced gas sensing. We compare some of its main characteristics with those of classical sensing. We address the problem of linear response, information channel capacity, missed alarms and false alarms.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:55:50 GMT" } ]
2009-11-13T00:00:00
[ [ "Kish", "L. B.", "" ], [ "Schmera", "G.", "" ], [ "Kwan", "Ch.", "" ], [ "Smulko", "J.", "" ], [ "Heszler", "P.", "" ], [ "Granqvist", "C. -G.", "" ] ]
0705.0161
Jia Shao
Jia Shao, Plamen Ch. Ivanov, Boris Podobnik, H. Eugene Stanley
Quantitative relations between corruption and economic factors
10 pages, 9 figures
Eur. Phys. J. B. 56 157-166(2007)
10.1140/epjb/e2007-00098-2
null
q-fin.GN physics.data-an physics.soc-ph
null
We report quantitative relations between corruption level and economic factors, such as country wealth and foreign investment per capita, which are characterized by a power law spanning multiple scales of wealth and investments per capita. These relations hold for diverse countries, and also remain stable over different time periods. We also observe a negative correlation between level of corruption and long-term economic growth. We find similar results for two independent indices of corruption, suggesting that the relation between corruption and wealth does not depend on the specific measure of corruption. The functional relations we report have implications when assessing the relative level of corruption for two countries with comparable wealth, and for quantifying the impact of corruption on economic growth and foreign investments.
[ { "version": "v1", "created": "Tue, 1 May 2007 19:56:52 GMT" } ]
2009-11-13T00:00:00
[ [ "Shao", "Jia", "" ], [ "Ivanov", "Plamen Ch.", "" ], [ "Podobnik", "Boris", "" ], [ "Stanley", "H. Eugene", "" ] ]
0705.0162
M. E. Carrington
M.E. Carrington and E. Kovalchuk
QED Electrical Conductivity using the 2PI Effective Action
24 pages, 21 figures
Phys.Rev.D76:045019,2007
10.1103/PhysRevD.76.045019
null
hep-ph
null
In this article we calculate the electrical conductivity in QED using the 2PI effective action. We use a modified version of the usual 2PI effective action which is defined with respect to self-consistent solutions of the 2-point functions. We show that the green functions obtained from this modified effective action satisfy ward identities and that the conductivity obtained from the kubo relation is gauge invariant. We work to 3-loop order in the modified 2PI effective action and show explicitly that the resulting expression for the conductivity contains the square of the amplitude that corresponds to all binary collision and production processes.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:48:05 GMT" } ]
2008-11-26T00:00:00
[ [ "Carrington", "M. E.", "" ], [ "Kovalchuk", "E.", "" ] ]
0705.0163
S. L. Bridle
Masahiro Takada (Tohoku Univ., Japan), Sarah Bridle (University College London)
Probing dark energy with cluster counts and cosmic shear power spectra: including the full covariance
32 pages, 15 figures. Revised version, invited original contribution to gravitational lensing focus issue, New Journal of Physics
New J.Phys.9:446,2007
10.1088/1367-2630/9/12/446
null
astro-ph
null
(Abridged) Combining cosmic shear power spectra and cluster counts is powerful to improve cosmological parameter constraints and/or test inherent systematics. However they probe the same cosmic mass density field, if the two are drawn from the same survey region, and therefore the combination may be less powerful than first thought. We investigate the cross-covariance between the cosmic shear power spectra and the cluster counts based on the halo model approach, where the cross-covariance arises from the three-point correlations of the underlying mass density field. Fully taking into account the cross-covariance as well as non-Gaussian errors on the lensing power spectrum covariance, we find a significant cross-correlation between the lensing power spectrum signals at multipoles l~10^3 and the cluster counts containing halos with masses M>10^{14}Msun. Including the cross-covariance for the combined measurement degrades and in some cases improves the total signal-to-noise ratios up to plus or minus 20% relative to when the two are independent. For cosmological parameter determination, the cross-covariance has a smaller effect as a result of working in a multi-dimensional parameter space, implying that the two observables can be considered independent to a good approximation. We also discuss that cluster count experiments using lensing-selected mass peaks could be more complementary to cosmic shear tomography than mass-selected cluster counts of the corresponding mass threshold. Using lensing selected clusters with a realistic usable detection threshold (S/N~6 for a ground-based survey), the uncertainty on each dark energy parameter may be roughly halved by the combined experiments, relative to using the power spectra alone.
[ { "version": "v1", "created": "Wed, 2 May 2007 15:13:56 GMT" }, { "version": "v2", "created": "Sat, 22 Sep 2007 13:39:51 GMT" } ]
2009-06-23T00:00:00
[ [ "Takada", "Masahiro", "", "Tohoku Univ., Japan" ], [ "Bridle", "Sarah", "", "University\n College London" ] ]
0705.0164
Andrei Linde
Andrei Linde
Inflationary Cosmology
60 pages, 10 figs, based on a talk given at the 22nd IAP Colloquium, "Inflation+25", Paris, June 2006
Lect.Notes Phys.738:1-54,2008
10.1007/978-3-540-74353-8_1
null
hep-th astro-ph gr-qc hep-ph
null
I give a general review of the history of inflationary cosmology and of its present status.
[ { "version": "v1", "created": "Wed, 2 May 2007 19:26:43 GMT" }, { "version": "v2", "created": "Wed, 16 May 2007 05:06:28 GMT" } ]
2009-09-29T00:00:00
[ [ "Linde", "Andrei", "" ] ]
0705.0165
Sheng Wang
Sheng Wang (Brookhaven; Columbia), Lam Hui (Columbia; ISCAP), Morgan May (Brookhaven), Zoltan Haiman (Columbia)
Is Modified Gravity Required by Observations? An Empirical Consistency Test of Dark Energy Models
7 pages, 3 figures. v2: constraints on DGP theory added; references added; final version published in Phys. Rev. D
Phys.Rev.D76:063503,2007
10.1103/PhysRevD.76.063503
null
astro-ph hep-ph hep-th
null
We apply the technique of parameter-splitting to existing cosmological data sets, to check for a generic failure of dark energy models. Given a dark energy parameter, such as the energy density Omega_Lambda or equation of state w, we split it into two meta-parameters with one controlling geometrical distances, and the other controlling the growth of structure. Observational data spanning Type Ia Supernovae, the cosmic microwave background (CMB), galaxy clustering, and weak gravitational lensing statistics are fit without requiring the two meta-parameters to be equal. This technique checks for inconsistency between different data sets, as well as for internal inconsistency within any one data set (e.g., CMB or lensing statistics) that is sensitive to both geometry and growth. We find that the cosmological constant model is consistent with current data. Theories of modified gravity generally predict a relation between growth and geometry that is different from that of general relativity. Parameter-splitting can be viewed as a crude way to parametrize the space of such theories. Our analysis of current data already appears to put sharp limits on these theories: assuming a flat universe, current data constrain the difference Omega_Lambda(geom) - Omega_Lambda(grow) to be -0.0044 +/- 0.0058 (68% C.L.); allowing the equation of state w to vary, the difference w(geom) - w(grow) is constrained to be 0.37 +/- 0.37 (68% C.L.). Interestingly, the region w(grow) > w(geom), which should be generically favored by theories that slow structure formation relative to general relativity, is quite restricted by data already. We find w(grow) < -0.80 at 2 sigma. As an example, the best-fit flat Dvali-Gabadadze-Porrati (DGP) model approximated by our parametrization lies beyond the 3 sigma contour for constraints from all the data sets.
[ { "version": "v1", "created": "Wed, 2 May 2007 05:49:41 GMT" }, { "version": "v2", "created": "Tue, 16 Oct 2007 19:22:42 GMT" } ]
2008-11-26T00:00:00
[ [ "Wang", "Sheng", "", "Brookhaven; Columbia" ], [ "Hui", "Lam", "", "Columbia; ISCAP" ], [ "May", "Morgan", "", "Brookhaven" ], [ "Haiman", "Zoltan", "", "Columbia" ] ]
0705.0166
S. L. Bridle
Sarah Bridle (University College London), Lindsay King (IoA, Cambridge)
Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements
14 pages and 9 figures. Replaced with final version accepted in "Gravitational Lensing" Focus Issue of the New Journal of Physics at http://www.iop.org/EJ/abstract/1367-2630/9/12/E09
New J.Phys.9:444,2007
10.1088/1367-2630/9/12/444
null
astro-ph
null
Cosmic shear constrains cosmology by exploiting the apparent alignments of pairs of galaxies due to gravitational lensing by intervening mass clumps. However galaxies may become (intrinsically) aligned with each other, and with nearby mass clumps, during their formation. This effect needs to be disentangled from the cosmic shear signal to place constraints on cosmology. We use the linear intrinsic alignment model as a base and compare it to an alternative model and data. If intrinsic alignments are ignored then the dark energy equation of state is biased by ~50 per cent. We examine how the number of tomographic redshift bins affects uncertainties on cosmological parameters and find that when intrinsic alignments are included two or more times as many bins are required to obtain 80 per cent of the available information. We investigate how the degradation in the dark energy figure of merit depends on the photometric redshift scatter. Previous studies have shown that lensing does not place stringent requirements on the photometric redshift uncertainty, so long as the uncertainty is well known. However, if intrinsic alignments are included the requirements become a factor of three tighter. These results are quite insensitive to the fraction of catastrophic outliers, assuming that this fraction is well known. We show the effect of uncertainties in photometric redshift bias and scatter. Finally we quantify how priors on the intrinsic alignment model would improve dark energy constraints.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:25:39 GMT" }, { "version": "v2", "created": "Fri, 18 Apr 2008 18:10:33 GMT" } ]
2009-06-23T00:00:00
[ [ "Bridle", "Sarah", "", "University College London" ], [ "King", "Lindsay", "", "IoA,\n Cambridge" ] ]
0705.0167
Joohyung Kim
Joohyung Kim
A duality between pairs of split decompositions for a $Q$-polynomial distance-regular graph
14 pages
null
null
null
math.CO
null
Let $\Gamma$ denote a $Q$-polynomial distance-regular graph with diameter $D \geq 3$ and standard module $V$. Recently Ito and Terwilliger introduced four direct sum decompositions of $V$; we call these the $(\mu,\nu)$--{\it split decompositions} of $V$, where $\mu, \nu \in \lbrace \downarrow, \uparrow \rbrace$. In this paper we show that the ($\downarrow,\downarrow$)--split decomposition and the ($\uparrow,\uparrow$)--split decomposition are dual with respect to the standard Hermitian form on $V$. We also show that the ($\downarrow,\uparrow$)--split decomposition and the ($\uparrow,\downarrow$)--split decomposition are dual with respect to the standard Hermitian form on $V$.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:12:21 GMT" } ]
2007-05-23T00:00:00
[ [ "Kim", "Joohyung", "" ] ]
0705.0168
Erkan Nane
Boris Baeumer, Mark M. Meerschaert and Erkan Nane
Brownian subordinators and fractional Cauchy problems
18 pages, minor spelling corrections
Trans. Amer. Math. Soc.361 (2009), 3915-3930.
10.1090/S0002-9947-09-04678-9
null
math.PR math.AP
null
A Brownian time process is a Markov process subordinated to the absolute value of an independent one-dimensional Brownian motion. Its transition densities solve an initial value problem involving the square of the generator of the original Markov process. An apparently unrelated class of processes, emerging as the scaling limits of continuous time random walks, involve subordination to the inverse or hitting time process of a classical stable subordinator. The resulting densities solve fractional Cauchy problems, an extension that involves fractional derivatives in time. In this paper, we will show a close and unexpected connection between these two classes of processes, and consequently, an equivalence between these two families of partial differential equations.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:26:33 GMT" }, { "version": "v2", "created": "Wed, 9 May 2007 20:25:31 GMT" } ]
2009-06-25T00:00:00
[ [ "Baeumer", "Boris", "" ], [ "Meerschaert", "Mark M.", "" ], [ "Nane", "Erkan", "" ] ]
0705.0169
Christopher Night
Christopher Night, Rosanne Di Stefano, Megan Schwamb
Beyond Caustic Crossings: Properties of Binary Microlensing Light Curves
17 pages, 17 figures, submitted to ApJ
null
10.1086/590320
KITP-07-18
astro-ph
null
Binary microlensing light curves have a variety of morphologies. Many are indistinguishable from point lens light curves. Of those that deviate from the point lens form, caustic crossing light curves have tended to dominate identified binary lens events. Other distinctive signatures of binary lenses include significant asymmetry, multiple peaks, and repeating events. We have quantified, using high resolution simulations, the theoretically expected relative numbers of each type of binary lens event, based on its measurable characteristics. We find that a microlensing survey with current levels of photometric uncertainty and sampling should find at least as many non-caustic crossing binary lens events as caustic crossing events; in future surveys with more sensitive photometry, the contribution of distinctive non-caustic crossing events will be even greater. To try to explain why caustic crossing light curves appear to be so dominant among the published binary lensing events, we investigate the influence of several physical effects, including blending, sampling rate, and various binary populations.
[ { "version": "v1", "created": "Wed, 2 May 2007 18:59:24 GMT" } ]
2009-11-13T00:00:00
[ [ "Night", "Christopher", "" ], [ "Di Stefano", "Rosanne", "" ], [ "Schwamb", "Megan", "" ] ]
0705.0170
Alexandra Pettet
Alexandra Pettet, Juan Souto
The spine which was no spine
null
null
null
null
math.GT
null
Let T_n be the Teichmueller space of flat metrics on the n-dimensional torus and identify SL(n,Z) with the corresponding mapping class group. We prove that the subset Y consisting of those points at which the systoles generate the fundamental group of the torus is, for n > 4, not contractible. In particular, Y is not an SL(n,Z)-equivariant deformation retract of T_n.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:30:41 GMT" } ]
2007-05-23T00:00:00
[ [ "Pettet", "Alexandra", "" ], [ "Souto", "Juan", "" ] ]
0705.0171
Wim de Boer
Wim de Boer, Johannes Bol, Alexander Furgeri, Steffen Mueller, Christian Sander, (University of Karlsruhe, Germany), Eleni Berdermann, Michal Pomorski (GSI, Darmstadt, Germany), Mika Huhtinen (CERN, Geneva, Switzerland)
Radiation hardness of diamond and silicon sensors compared
6 pages, 4 figurs, invited talk at the Hasselt Diamond Workshop, Feb. 2007
Phys.StatusSolidi204:3009,2007
10.1002/pssa.200776327
null
physics.ins-det
null
The radiation hardness of silicon charged particle sensors is compared with single crystal and polycrystalline diamond sensors, both experimentally and theoretically. It is shown that for Si- and C-sensors, the NIEL hypothesis, which states that the signal loss is proportional to the Non-Ionizing Energy Loss, is a good approximation to the present data. At incident proton and neutron energies well above 0.1 GeV the radiation damage is dominated by the inelastic cross section, while at non-relativistic energies the elastic cross section prevails. The smaller inelastic nucleon-Carbon cross section and the light nuclear fragments imply that at high energies diamond is an order of magnitude more radiation hard than silicon, while at energies below 0.1 GeV the difference becomes significantly smaller.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:32:55 GMT" } ]
2015-05-13T00:00:00
[ [ "de Boer", "Wim", "", "GSI, Darmstadt, Germany" ], [ "Bol", "Johannes", "", "GSI, Darmstadt, Germany" ], [ "Furgeri", "Alexander", "", "GSI, Darmstadt, Germany" ], [ "Mueller", "Steffen", "", "GSI, Darmstadt, Germany" ], [ "Sander", "Christian", "", "GSI, Darmstadt, Germany" ], [ "Berdermann", "Eleni", "", "GSI, Darmstadt, Germany" ], [ "Pomorski", "Michal", "", "GSI, Darmstadt, Germany" ], [ "Huhtinen", "Mika", "", "CERN, Geneva,\n Switzerland" ] ]
0705.0172
Andrew Essin
Andrew M. Essin and J. E. Moore
Topological insulators beyond the Brillouin zone via Chern parity
12 pages, 10 figures
Phys. Rev. B 76, 165307 (2007)
10.1103/PhysRevB.76.165307
null
cond-mat.mes-hall
null
The topological insulator is an electronic phase stabilized by spin-orbit coupling that supports propagating edge states and is not adiabatically connected to the ordinary insulator. In several ways it is a spin-orbit-induced analogue in time-reversal-invariant systems of the integer quantum Hall effect (IQHE). This paper studies the topological insulator phase in disordered two-dimensional systems, using a model graphene Hamiltonian introduced by Kane and Mele as an example. The nonperturbative definition of a topological insulator given here is distinct from previous efforts in that it involves boundary phase twists that couple only to charge, does not refer to edge states, and can be measured by pumping cycles of ordinary charge. In this definition, the phase of a Slater determinant of electronic states is determined by a Chern parity analogous to Chern number in the IQHE case. Numerically we find, in agreement with recent network model studies, that the direct transition between ordinary and topological insulators that occurs in band structures is a consequence of the perfect crystalline lattice. Generically these two phases are separated by a metallic phase, which is allowed in two dimensions when spin-orbit coupling is present. The same approach can be used to study three-dimensional topological insulators.
[ { "version": "v1", "created": "Wed, 2 May 2007 17:35:30 GMT" } ]
2009-12-16T00:00:00
[ [ "Essin", "Andrew M.", "" ], [ "Moore", "J. E.", "" ] ]
0705.0173
Izhar Neder
I. Neder, N. Ofek, Y. Chung, M. Heiblum, D. Mahalu, and V. Umansky
Interference between two independent electrons: observation of two-particle Aharonov-Bohm interference
16 pages, 4 figures
null
null
null
cond-mat.mes-hall quant-ph
null
Very much like the ubiquitous quantum interference of a single particle with itself, quantum interference of two independent, but indistinguishable, particles is also possible. This interference is a direct result of quantum exchange statistics, however, it is observed only in the joint probability to find the particles in two separated detectors. Here we report the first observation of such interference fringes between two independent and non-interacting electrons in an interferometer proposed by Yurke et al. and Samuelsson et al. Our experiment resembles the "Hanbury Brown and Twiss" (HBT) experiment, which was performed with classical waves. In the experiment, two independent and mutually incoherent electron beams were each partitioned into two trajectories. The combined four trajectories enclosed an Aharonov-Bohm (AB) flux (but not the two trajectories of a single electron). While individual currents were found to be independent of the AB flux, as expected, the cross-correlation between current fluctuations in two opposite points across the device exhibited strong AB oscillations. This is a direct signature of orbital entanglement between two electrons even though they never interact with each other.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:43:37 GMT" } ]
2007-05-23T00:00:00
[ [ "Neder", "I.", "" ], [ "Ofek", "N.", "" ], [ "Chung", "Y.", "" ], [ "Heiblum", "M.", "" ], [ "Mahalu", "D.", "" ], [ "Umansky", "V.", "" ] ]
0705.0174
Kai Chen
Kai Chen, Che-Ming Li, Qiang Zhang, Yu-Ao Chen, Alexander Goebel, Shuai Chen, Alois Mair, Jian-Wei Pan
Experimental realization of one-way quantum computing with two-photon four-qubit cluster states
4 pages, 3 figures
Phys. Rev. Lett. 99, 120503 (2007)
10.1103/PhysRevLett.99.120503
null
quant-ph
null
We report an experimental realization of one-way quantum computing on a two-photon four-qubit cluster state. This is accomplished by developing a two-photon cluster state source entangled both in polarization and spatial modes. With this special source, we implemented a highly efficient Grover's search algorithm and high-fidelity two qubits quantum gates. Our experiment demonstrates that such cluster states could serve as an ideal source and a building block for rapid and precise optical quantum computation.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:57:12 GMT" }, { "version": "v2", "created": "Tue, 18 Sep 2007 11:01:19 GMT" } ]
2012-10-30T00:00:00
[ [ "Chen", "Kai", "" ], [ "Li", "Che-Ming", "" ], [ "Zhang", "Qiang", "" ], [ "Chen", "Yu-Ao", "" ], [ "Goebel", "Alexander", "" ], [ "Chen", "Shuai", "" ], [ "Mair", "Alois", "" ], [ "Pan", "Jian-Wei", "" ] ]
0705.0175
Victor H. Moll
Victor H. Moll
The integrals in Gradshteyn and Ryzhik. Part 3: Combinations of Logarithms and Exponentials
5 pages
null
null
null
math.CA
null
We present the evaluation of a family of exponential-logarithmic integrals. These have integrands of the form P(exp(x),ln(x)) where P is a polynomial. The examples presented here appear in sections 4.33, 4.34 and 4.35 in the classical table of integrals by I. Gradshteyn and I. Ryzhik.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:46:39 GMT" } ]
2007-05-23T00:00:00
[ [ "Moll", "Victor H.", "" ] ]
0705.0176
Lu Zou
Lu Zou, Ji Wang, Prem Basnet, Elizabeth K. Mann
Line tension and structure of smectic liquid crystal multilayers at the air-water interface
21 pages, 6 figures
null
10.1103/PhysRevE.76.031602
null
cond-mat.soft
null
At the air/water interface, 4,-8-alkyl[1,1,-biphenyl]-4-carbonitrile (8CB) domains with different thicknesses coexist in the same Langmuir film, as multiple bilayers on a monolayer. The edge dislocation at the domain boundary leads to line tension, which determines the domain shape and dynamics. By observing the domain relaxation process starting from small distortions, we find that the line tension is linearly dependent on the thickness difference between the coexisting phases in the film. Comparisons with theoretical treatments in the literature suggest that the edge dislocation at the boundary locates near the center of the film, which means that the 8CB multilayers are almost symmetric with respect to the air/water interface.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:53:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Zou", "Lu", "" ], [ "Wang", "Ji", "" ], [ "Basnet", "Prem", "" ], [ "Mann", "Elizabeth K.", "" ] ]
0705.0177
Sergey Fedosov
S. N. Fedosov, A. E. Sergeeva, T. A. Revenyuk, A. F. Butenko
Application of Corona Discharge for Poling Ferroelectric and Nonlinear Optical Polymers
4 pages, 3 figures
null
null
null
cond-mat.mtrl-sci
null
Four modifications of the corona triode are described for charging polar polymers with ferroelectric or non-linear optical properties. Advantages of the constant current modification of corona poling are illustrated and discussed.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:07:13 GMT" } ]
2007-05-23T00:00:00
[ [ "Fedosov", "S. N.", "" ], [ "Sergeeva", "A. E.", "" ], [ "Revenyuk", "T. A.", "" ], [ "Butenko", "A. F.", "" ] ]
0705.0178
Abhishek Parakh
Abhishek Parakh
Oblivious Transfer based on Key Exchange
10 pages
Cryptologia, Volume 32, Issue 1 January 2008, pages 37 - 44
10.1080/01611190701593228
null
cs.CR
null
Key-exchange protocols have been overlooked as a possible means for implementing oblivious transfer (OT). In this paper we present a protocol for mutual exchange of secrets, 1-out-of-2 OT and coin flipping similar to Diffie-Hellman protocol using the idea of obliviously exchanging encryption keys. Since, Diffie-Hellman scheme is widely used, our protocol may provide a useful alternative to the conventional methods for implementation of oblivious transfer and a useful primitive in building larger cryptographic schemes.
[ { "version": "v1", "created": "Wed, 2 May 2007 02:56:25 GMT" } ]
2008-01-10T00:00:00
[ [ "Parakh", "Abhishek", "" ] ]
0705.0179
Victor H. Moll
Victor H. Moll
The integrals in Gradshteyn and Ryzhik. Part 4: The Gamma function
9 pages
null
null
null
math.CA
null
We present a systematic derivation of some definite integrals in the classical table of Gradshteyn and Ryzhik that can be reduced to the gamma function.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:55:40 GMT" } ]
2007-05-23T00:00:00
[ [ "Moll", "Victor H.", "" ] ]
0705.0180
Dietrich Bodeker
D. Bodeker (Bielefeld U), K. Rummukainen (Oulu U)
Non-abelian plasma instabilities for strong anisotropy
28 pages, 17 figures
JHEP0707:022,2007
10.1088/1126-6708/2007/07/022
null
hep-ph
null
We numerically investigate gauge field instabilities in anisotropic SU(2) plasmas using weak field initial conditions. The growth of unstable modes is stopped by non-abelian effects for moderate anisotropy. If we increase the anisotropy the growth continues beyond the non-abelian saturation bound. We find strong indications that the continued growth is not due to over-saturation of infrared field modes, but instead due to very rapid growth of high momentum modes which are not unstable in the weak field limit. The saturation amplitude strongly depends on the initial conditions. For strong initial fields we do not observe the sustained growth.
[ { "version": "v1", "created": "Tue, 1 May 2007 20:56:41 GMT" } ]
2008-11-26T00:00:00
[ [ "Bodeker", "D.", "", "Bielefeld U" ], [ "Rummukainen", "K.", "", "Oulu U" ] ]
0705.0181
Pawel Kurzynski
Andrzej Grudka and Pawel Kurzynski
Is there contextuality for a single qubit?
4 pages, 1 figure, comments welcome
Phys. Rev. Lett. 100, 160401 (2008)
10.1103/PhysRevLett.100.160401
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was presented by Cabello and Nakamura [A. Cabello, Phys. Rev. Lett. 90, 190401 (2003)], that the Kochen-Specker theorem applies to two dimensions if one uses Positive Operator-Valued Measures. We show that contextuality in their models is not of the Kochen-Specker type. It is rather the result of not keeping track of the whole system on which the measurement is performed. This is connected to the fact that there is no one-to-one correspondence between POVM elements and projectors on the extended Hilbert space and the same POVM element has to originate from two different projectors when used in Cabello's and Nakamura's models. Moreover, we propose a hidden-variable formulation of the above models.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:27:33 GMT" }, { "version": "v2", "created": "Tue, 1 Jul 2008 09:38:35 GMT" } ]
2008-07-24T00:00:00
[ [ "Grudka", "Andrzej", "" ], [ "Kurzynski", "Pawel", "" ] ]
0705.0182
Simon Glover
S. C. O. Glover and A.-K. Jappsen
Star formation at very low metallicity. I: Chemistry and cooling at low densities
55 pages, 1 figure. Accepted by ApJ. This revised version fixes a number of typographical errors
Astrophys.J.666:1-19,2007
10.1086/519445
null
astro-ph
null
We present a simplified chemical and thermal model designed to allow computationally efficient study of the thermal evolution of metal-poor gas within large numerical simulations. Our main simplification is the neglect of the molecular chemistry of the heavy elements. The only molecular chemistry retained within the model is the formation and destruction of molecular hydrogen. Despite this major simplification, the model allows for accurate treatment of the thermal evolution of the gas within a large volume of parameter space. It is valid for temperatures 50 < T < 10000 K and metallicities 0 < Z < 0.1 Z_solar. In gas with a metallicity Z = 0.1 Z_solar, and in the absence of an incident ultraviolet radiation field, it is valid for hydrogen number densities n_H < 500 / t_char cm^-3, where t_char is the size in Myr of the characteristic physical timescale of interest in the problem. If Z << 0.1 Z_solar, or if a strong ultraviolet radiation field is present, then the model remains accurate up to significantly higher densities. We also discuss some possible applications of this model.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:50:52 GMT" }, { "version": "v2", "created": "Thu, 23 Aug 2007 16:29:23 GMT" } ]
2009-06-23T00:00:00
[ [ "Glover", "S. C. O.", "" ], [ "Jappsen", "A. -K.", "" ] ]
0705.0183
Stuart White
Roger R. Smith, Stuart A. White and Alan D. Wiggins
Normalizers of Irreducible Subfactors
33 Pages
null
null
null
math.OA
null
We consider normalizers of an irreducible inclusion $N\subseteq M$ of $\mathrm{II}_1$ factors. In the infinite index setting an inclusion $uNu^*\subseteq N$ can be strict, forcing us to also investigate the semigroup of one-sided normalizers. We relate these normalizers of $N$ in $M$ to projections in the basic construction and show that every trace one projection in the relative commutant $N'\cap < M,e_N>$ is of the form $u^*e_Nu$ for some unitary $u\in M$ with $uNu^*\subseteq N$. This enables us to identify the normalizers and the algebras they generate in several situations. In particular each normalizer of a tensor product of irreducible subfactors is a tensor product of normalizers modulo a unitary. We also examine normalizers of irreducible subfactors arising from subgroup--group inclusions $H\subseteq G$. Here the normalizers are the normalizing group elements modulo a unitary from $L(H)$. We are also able to identify the finite trace $L(H)$-bimodules in $\ell^2(G)$ as double cosets which are also finite unions of left cosets.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:41:06 GMT" } ]
2007-05-23T00:00:00
[ [ "Smith", "Roger R.", "" ], [ "White", "Stuart A.", "" ], [ "Wiggins", "Alan D.", "" ] ]
0705.0184
Li-Ming Si
Li-Ming Si and Ji-Xuan Hou
Quantum phase transition and entanglement in Li atom system
5 pages, 2 figures
Science in China Series G: Physics, Mechanics & Astronomy, 2008, Vol. 51, No. 11, pp: 1677-1681
10.1007/s11433-008-0180-9
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the quantum phase transition and entanglement in s1=1/2 and s2=1 spin pair system by the exact diagonalization method. We show that, for this exactly solvable quantum bi-spin system, entanglement appears before quantum phase transition and disappears after it. Moreover, we show that the von Neumann entropy, as a measure of entanglement, can reveal quantum phase transition in this system.
[ { "version": "v1", "created": "Tue, 1 May 2007 21:41:41 GMT" }, { "version": "v2", "created": "Mon, 20 Oct 2008 14:48:41 GMT" } ]
2009-11-13T00:00:00
[ [ "Si", "Li-Ming", "" ], [ "Hou", "Ji-Xuan", "" ] ]
0705.0185
Jonathan Braithwaite
J. Braithwaite (MPA Garching, CITA Toronto)
The stability of poloidal magnetic fields in rotating stars
A&A accepted. Animations available at http://www.cita.utoronto.ca/~jon/research/rp_anims.html
null
10.1051/0004-6361:20065903
null
astro-ph
null
The stability of large-scale magnetic fields in rotating stars is explored, using 3D numerical hydrodynamics to follow the evolution of an initial poloidal field. It is found that the field is subject to an instability, located initially on the magnetic equator, whereby the gas is displaced in a direction parallel to the magnetic axis. If the magnetic axis is parallel to the rotation axis, the rotation does not affect the initial linear growth of the instability, but does restrict the growth of the instability outside of the equatorial zone. The magnetic energy decays on a timescale which is a function of the Alfv\'en crossing time and the rotation speed, but short compared to any evolutionary timescale. No evidence is found for a possible stable end state to evolve from an initial axisymmetric poloidal field. The field of an oblique rotator is similarly unstable, in both cases regardless of the rotation speed.
[ { "version": "v1", "created": "Tue, 1 May 2007 23:30:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Braithwaite", "J.", "", "MPA Garching, CITA Toronto" ] ]
0705.0186
Yang Liu
Yang Liu and Karin A. Dahmen
No-passing Rule in the Ground State Evolution of the Random-Field Ising Model
7 pages, 4 figures
Phys. Rev. E 76, 031106 (2007)
10.1103/PhysRevE.76.031106
null
cond-mat.stat-mech cond-mat.dis-nn
null
We exactly prove the no-passing rule in the ground state evolution of the random-field Ising model (RFIM) with monotonically varying external field. In particular, we show that the application of the no-passing rule can speed up the calculation of the zero-temperature equilibrium $M(H)$ curve dramatically.
[ { "version": "v1", "created": "Tue, 1 May 2007 23:01:17 GMT" } ]
2008-02-23T00:00:00
[ [ "Liu", "Yang", "" ], [ "Dahmen", "Karin A.", "" ] ]
0705.0187
Saeed Saremi
Saeed Saremi
RKKY in half-filled bipartite lattices: graphene as an example
v3. The published version. 6 pages, 1 figure
Phys. Rev. B 76, 184430 (2007) (6 pages)
10.1103/PhysRevB.76.184430
null
cond-mat.str-el
null
We first present a simple proof that for any bipartite lattice at half filling the RKKY interaction is antiferromagnetic between impurities on opposite (i.e., A and B) sublattices and is ferromagnetic between impurities on the same sublattices. This result is valid on all length scales. We then focus on the honeycomb lattice and examine the theorem in the long distance limit by performing the low energy calculation using Dirac electrons. To find the universal (cutoff free) result we perform the calculation in smooth cutoff schemes, as we show that the calculation based on a sharp cutoff leads to wrong results. We also find the long distance behavior of the RKKY interaction between "plaquette" impurities in both coherent and incoherent regimes.
[ { "version": "v1", "created": "Wed, 2 May 2007 19:28:29 GMT" }, { "version": "v2", "created": "Wed, 9 May 2007 22:44:04 GMT" }, { "version": "v3", "created": "Mon, 26 Nov 2007 21:05:46 GMT" } ]
2007-11-26T00:00:00
[ [ "Saremi", "Saeed", "" ] ]
0705.0188
Serge Tabachnikov
D. Genin, B. Khesin, S. Tabachnikov
Geodesics on an ellipsoid in Minkowski space
null
null
null
null
math.DG math.DS
null
We describe the geometry of geodesics on a Lorentz ellipsoid: give explicit formulas for the first integrals (pseudo-confocal coordinates), curvature, geodesically equivalent Riemannian metric, the invariant area-forms on the time- and space-like geodesics and invariant 1-form on the space of null geodesics. We prove a Poncelet-type theorem for null geodesics on the ellipsoid: if such a geodesic close up after several oscillations in the "pseudo-Riemannian belt", so do all other null geodesics on this ellipsoid.
[ { "version": "v1", "created": "Tue, 1 May 2007 23:44:26 GMT" } ]
2007-05-23T00:00:00
[ [ "Genin", "D.", "" ], [ "Khesin", "B.", "" ], [ "Tabachnikov", "S.", "" ] ]
0705.0189
Yousaf Mahmood Butt
Yousaf Butt
Note on XMM-Newton observations of the first unidentified TeV gamma-ray source TeV J2032+4130 by Horns et al. astro-ph/0705.0009
null
null
null
null
astro-ph
null
I comment on the -- apparent -- diffuse X-ray emission reported by Horns et al. in their XMM observations of TeV J2032+4130
[ { "version": "v1", "created": "Wed, 2 May 2007 19:33:50 GMT" } ]
2007-05-23T00:00:00
[ [ "Butt", "Yousaf", "" ] ]
0705.0190
Dima Arinkin
D. Arinkin
Cohomology of line bundles on compactified Jacobians
12 pages; second version with minor changes throughout the text
null
null
null
math.AG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let C be an integral projective curve with surficial singularities. We prove that topologically trivial line bundles on the compactified Jacobian of C are in one-to-one correspondence with line bundles on C (the autoduality conjecture), and compute the cohomology of the line bundles. We also show that the natural Fourier-Mukai functor between the derived categories of quasi-coherent sheaves on the Jacobian and on the compactified Jacobian is fully faithful.
[ { "version": "v1", "created": "Wed, 2 May 2007 01:23:05 GMT" }, { "version": "v2", "created": "Tue, 3 Aug 2010 19:52:36 GMT" } ]
2010-08-04T00:00:00
[ [ "Arinkin", "D.", "" ] ]
0705.0191
Florentin Smarandache
Florentin Smarandache
On Solving General Linear Equations in the Set of Natural Numbers
4 pages
In the book G\'eneralistions et G\'en\'eralit\'es, by F. Smarandache, Ed. Nouvelle, F\`es, Morocco, pp. 36-38, 1984
null
null
math.GM
null
In this paper one shows if the number of natural solutions of a general linear equation is limited or not. Also, it is presented a method of solving the Diophantine equation $ax-by=c$ in the set of natural numbers, and an example of solving in $N$ a Diophantine equation with three variables.
[ { "version": "v1", "created": "Wed, 2 May 2007 01:44:36 GMT" } ]
2007-05-23T00:00:00
[ [ "Smarandache", "Florentin", "" ] ]
0705.0192
Jan Lang
D.E.Edmunds (Cardiff University), J.Lang (The Ohio State University)
Asymptotics for eigenvalues of a non-linear integral system
LaTeX, 13 pages
null
null
Ohio State University MRI Preprints 06-10
math.SP math.CA
null
We show the asymptotic behavior of the eigenvalues of the non-linear integral system related to the (p,q)-Laplacian.
[ { "version": "v1", "created": "Wed, 2 May 2007 02:13:18 GMT" } ]
2007-05-23T00:00:00
[ [ "Edmunds", "D. E.", "", "Cardiff University" ], [ "Lang", "J.", "", "The Ohio State University" ] ]
0705.0193
Alireza Abdollahi
Alireza Abdollahi
1-Factorizations of Cayley graphs
null
null
null
null
math.CO math.GR
null
In this note we prove that all connected Cayley graphs of every finite group $Q \times H$ are 1-factorizable, where $Q$ is any non-trivial group of 2-power order and $H$ is any group of odd order.
[ { "version": "v1", "created": "Wed, 2 May 2007 02:17:45 GMT" } ]
2007-05-23T00:00:00
[ [ "Abdollahi", "Alireza", "" ] ]
0705.0194
Alireza Abdollahi
A. Abdollahi, H. R. Maimani and R. Torabi
On the automorphism group of a possible symmetric $(81,16,3)$ design
null
null
null
null
math.CO math.GR
null
In this paper we study the automorphism group of a possible symmetric $(81,16,3)$ design.
[ { "version": "v1", "created": "Wed, 2 May 2007 02:30:28 GMT" } ]
2007-05-23T00:00:00
[ [ "Abdollahi", "A.", "" ], [ "Maimani", "H. R.", "" ], [ "Torabi", "R.", "" ] ]
0705.0195
Chinping Chen
Lin He and Chinping Chen
Effect of temperature-dependent shape anisotropy on coercivity with aligned Stoner-Wohlfarth soft ferromagnets
22 pages, 2 figures, 1 table, Accepted by Phys. Rev. B
Phy. Rev. B 75, 184424 (2007)
10.1103/PhysRevB.75.184424
null
cond-mat.mtrl-sci
null
The temperature variation effect of shape anisotropy on the coercivity, HC(T), for the aligned Stoner-Wohlfarth (SW) soft ferromagnets, such as fcc Ni, fcc Co and bcc Fe, are investigated within the framework of Neel-Brown (N-B) analysis. An extended N-B equation is thus proposed,by introducing a single dimensionless correction function, the reduced magnetization, m(\tao) = MS(T)/MS(0), in which \tao = T/TC is the reduced temperature, MS(T) is the saturation magnetization, and TC is the Curie temperature. The factor, m(\tao), accounts for the temperature-dependent effect of the shape anisotropy. The constants, H0 and E0, are for the switching field at zero temperature and the potential barrier at zero field, respectively. According to this newly derived equation, the blocking temperature above which the properties of superparamagnetism show up is described by the expression, TB = E0m^2(\tao)/[kBln(t/t0)], with the extra correction factor m^2(\tao). The possible effect on HC(T) and the blocking temperature, TB, attributed to the downshift of TC resulting from the finite size effect has been discussed also.
[ { "version": "v1", "created": "Wed, 2 May 2007 02:42:12 GMT" } ]
2009-11-13T00:00:00
[ [ "He", "Lin", "" ], [ "Chen", "Chinping", "" ] ]
0705.0196
Nobukuni Hamamoto Dr
Nobukuni Hamamoto, Makito Oi, Naoki Onishi
Cranked Hartree-Fock-Bogoliubov Calculation for Rotating Bose-Einstein Condensates
accepted to Phys. Rev. A
null
10.1103/PhysRevA.75.063614
null
cond-mat.other nucl-th
null
A rotating bosonic many-body system in a harmonic trap is studied with the 3D-Cranked Hartree-Fock-Bogoliubov method at zero temperature, which has been applied to nuclear many-body systems at high spin. This method is a variational method extended from the Hartree-Fock theory, which can treat the pairing correlations in a self-consistent manner. An advantage of this method is that a finite-range interaction between constituent particles can be used in the calculation, unlike the original Gross-Pitaevskii approach. To demonstrate the validity of our method, we present a calculation for a toy model, that is, a rotating system of ten bosonic particles interacting through the repulsive quadrupole-quadrupole interaction in a harmonic trap. It is found that the yrast states, the lowest-energy states for the given total angular momentum, does not correspond to the Bose-Einstein condensate, except a few special cases. One of such cases is a vortex state, which appears when the total angular momentum $L$ is twice the particle number $N$ (i.e., $L=2N$).
[ { "version": "v1", "created": "Wed, 2 May 2007 03:01:32 GMT" } ]
2009-11-13T00:00:00
[ [ "Hamamoto", "Nobukuni", "" ], [ "Oi", "Makito", "" ], [ "Onishi", "Naoki", "" ] ]
0705.0197
Tshilidzi Marwala
Tshilidzi Marwala, Unathi Mahola and Snehashish Chakraverty
Fault Classification in Cylinders Using Multilayer Perceptrons, Support Vector Machines and Guassian Mixture Models
10 pages, 2 figures, 4 tables
Computer Assisted Mechanics and Engineering Sciences, Vol. 14, No. 2, 2007.
null
null
cs.AI
null
Gaussian mixture models (GMM) and support vector machines (SVM) are introduced to classify faults in a population of cylindrical shells. The proposed procedures are tested on a population of 20 cylindrical shells and their performance is compared to the procedure, which uses multi-layer perceptrons (MLP). The modal properties extracted from vibration data are used to train the GMM, SVM and MLP. It is observed that the GMM produces 98%, SVM produces 94% classification accuracy while the MLP produces 88% classification rates.
[ { "version": "v1", "created": "Wed, 2 May 2007 03:13:28 GMT" } ]
2007-05-23T00:00:00
[ [ "Marwala", "Tshilidzi", "" ], [ "Mahola", "Unathi", "" ], [ "Chakraverty", "Snehashish", "" ] ]