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0705.3798
Remco Hofstad van der
Remco van der Hofstad, Mark Holmes, Gordon Slade
Extension of the generalised inductive approach to the lace expansion: Full proof
null
null
null
null
math.PR math-ph math.MP
null
This paper extends the inductive approach to the lace expansion of van der Hofstad and Slade in order to prove Gaussian asymptotic behaviour for models with critical dimension other than 4. The results are applied by Holmes to study sufficiently spread-out lattice trees in dimensions d>8 and may also be applicable to percolation in dimensions d>6.
[ { "version": "v1", "created": "Fri, 25 May 2007 15:43:24 GMT" } ]
2007-05-28T00:00:00
[ [ "van der Hofstad", "Remco", "" ], [ "Holmes", "Mark", "" ], [ "Slade", "Gordon", "" ] ]
0705.3799
Eli Dwek
Eli Dwek, Frederic Galliano, and Anthony P. Jones
The Evolution of Dust in the Early Universe with Applications to the Galaxy SDSS J1148+5251
35 pages, 11 figures, accepted for publication in the Astrophysical Journal
Astrophys.J.662:927-939,2007
10.1086/518430
null
astro-ph
null
Dusty hyperluminous galaxies in the early universe provide unique environments for studying the role of massive stars in the formation and destruction of dust. At redshifts above ~ 6, when the universe was less than ~ 1 Gyr old, dust could have only condensed in the explosive ejecta of Type II supernovae (SNe), since most of the progenitors of the AGB stars, the major alternative source of interstellar dust, did not have time to evolve off the main sequence since the onset of star formation. In this paper we present analytical models for the evolution of the gas, dust, and metals in high redshift galaxies, with a special application to SDSS J1148+5251, a hyperluminous quasar at z = 6.4. We find that an average supernova must condense at least 1 Msun of dust to account for the observed dust mass in this quasar. Observationally, it is in excess of the largest dust yield of ~0.02 Msun found thus far in the ejecta of any SN. If future observations find this to be a typical supernova dust yield, then additional processes, such as accretion onto preexisting grains, or condensation around the AGN will need to be invoked to account for the large amount of dust in this and similar objects. The galaxy's star formation history is still uncertain, and current observations of the gas, metal, and dust contents of J1148 can be reproduced by either an intensive and short burst of star formation (~ 1000 Msun/yr) with a duration of ~ 100 Myr, or a much lower star formation rate (~ 100 Msun/yr) occurring over the lifetime of the galaxy.
[ { "version": "v1", "created": "Fri, 25 May 2007 15:47:09 GMT" } ]
2009-11-13T00:00:00
[ [ "Dwek", "Eli", "" ], [ "Galliano", "Frederic", "" ], [ "Jones", "Anthony P.", "" ] ]
0705.3800
David Whelan
D.G. Whelan, D. Devost, V. Charmandaris, J.A. Marshall, J.R. Houck
Spitzer/IRS Imaging and Spectroscopy of the luminous infrared galaxy NGC 6052 (Mrk 297)
20 pages in preprint form, estimated 7 pages in ApJ Aeptember 10, 2007, v666n 2 issue, six encapsulated postscript figures
Astrophys.J.666:896-902,2007
10.1086/520104
null
astro-ph
null
We present photometric and spectroscopic data of the interacting starburst galaxy NGC 6052 obtained with the Spitzer Space Telescope. The mid-infrared (MIR) spectra of the three brightest spatially resolved regions in the galaxy are remarkably similar and are consistent with dust emission from young nearly coeval stellar populations. Analysis of the brightest infrared region of the system, which contributes ~18.5 % of the total 16\micron flux, indicates that unlike similar off-nuclear infrared-bright regions found in Arp 299 or NGC 4038/9, its MIR spectrum is inconsistent with an enshrouded hot dust (T > 300K) component. Instead, the three brightest MIR regions all display dust continua of temperatures less than ~ 200K. These low dust temperatures indicate the dust is likely in the form of a patchy screen of relatively cold material situated along the line of sight. We also find that emission from polycyclic aromatic hydrocarbons (PAHs) and the forbidden atomic lines is very similar for each region. We conclude that the ionization regions are self-similar and come from young (about 6 Myr) stellar populations. A fourth region, for which we have no MIR spectra, exhibits MIR emission similar to tidal tail features in other interacting galaxies.
[ { "version": "v1", "created": "Fri, 25 May 2007 15:51:56 GMT" } ]
2009-11-13T00:00:00
[ [ "Whelan", "D. G.", "" ], [ "Devost", "D.", "" ], [ "Charmandaris", "V.", "" ], [ "Marshall", "J. A.", "" ], [ "Houck", "J. R.", "" ] ]
0705.3801
Josep Marti
Josep Marti, Josep M. Paredes, Ishwara Chandra C. H., Valenti Bosch-Ramon
Deep radio images of the HEGRA and Whipple TeV sources in the Cygnus OB2 region
10 pages, 8 figures, 1 online catalogue. Accepted for publication in Astronomy & Astrophysics
null
10.1051/0004-6361:20077712
null
astro-ph
null
Context. The modern generation of Cherenkov telescopes has revealed a new population of gamma-ray sources in the Galaxy. Some of them have been identified with previously known X-ray binary systems while other remain without clear counterparts a lower energies. Our initial goal here was reporting on extensive radio observations of the first extended and yet unidentified source, namely TeV J2032+4130. This object was originally detected by the HEGRA telescope in the direction of the Cygnus OB2 region and its nature has been a matter of debate during the latest years. Aims. We aim to pursue our radio exploration of the TeV J2032+4130 position that we initiated in a previous paper but taking now into account the latest results from new Whipple and MILAGRO TeV telescopes. Methods. Our investigation is mostly based on interferometric radio observations with the Giant Metre Wave Radio Telescope (GMRT) close to Pune (India) and the Very Large Array (VLA) in New Mexico (USA). We also conducted near infrared observations with the 3.5 m telescope and the OMEGA2000 camera at the Centro Astronomico Hispano Aleman (CAHA) in Almeria (Spain). Results. We present deep radio maps centered on the TeV J2032+4130 position at different wavelengths. In particular, our 49 and 20 cm maps cover a field of view larger than half a degree that fully includes the Whipple position and the peak of MILAGRO emission. Our most important result here is a catalogue of 153 radio sources detected at 49 cm within the GMRT antennae primary beam with a full width half maximum (FWHM) of 43 arc-minute. Moreover, our multi-configuration VLA images reveal the non-thermal extended emission previously reported by us with improved angular resolution.
[ { "version": "v1", "created": "Fri, 25 May 2007 15:53:03 GMT" } ]
2009-11-13T00:00:00
[ [ "Marti", "Josep", "" ], [ "Paredes", "Josep M.", "" ], [ "H.", "Ishwara Chandra C.", "" ], [ "Bosch-Ramon", "Valenti", "" ] ]
0705.3802
Alexander Lenz
Alexander Lenz
Theoretical status of $B_s$-mixing and lifetimes of heavy hadrons
6 pages, invited talk at Hadron Collider Physics Symposium 2007, La Biodola, Isola d'Elba, Italy, misprints in Note added corrected
Nucl.Phys.Proc.Suppl.177-178:81-86,2008
10.1016/j.nuclphysbps.2007.11.089
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the theoretical status of the lifetime ratios $\tau_{B^+} / \tau_{B_d}$, $\tau_{B_s} / \tau_{B_d}$, $\tau_{\Lambda_b} / \tau_{B_d}$ and $\tau_{B_c}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$. $\Delta M_s$ and $\Delta \Gamma_s$ suffer from large uncertainties due to the badly known decay constants, while the ratio $\Delta \Gamma_s / \Delta M_s$ can be determined with almost no non-perturbative uncertainties, therefore it can be used perfectly to find possible new physics contributions in the mixing parameters. We suggest a very clear method of visualizing the bounds on new physics and demonstrate this by combining the latest experimental numbers on the mixing quantities quantities with theory - one already gets some hints for new physics contributions, but more precise experimental numbers are needed to draw some definite conclusions. We conclude with a ranking list of all the discussed quantities according to their current theoretical uncertainties and point out possible improvements.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:08:56 GMT" }, { "version": "v2", "created": "Mon, 28 May 2007 12:02:54 GMT" }, { "version": "v3", "created": "Sun, 1 Jul 2012 16:47:34 GMT" } ]
2012-07-03T00:00:00
[ [ "Lenz", "Alexander", "" ] ]
0705.3803
J\=anis C\=irulis
J\{=}anis C\={\i}rulis (University of Latvia)
On implications in sectionally pseudocomplemented posets
10 pages, no figures, typos corrected
Acta Sci. Math. (Szeged) 74 (2008), 477--491
null
null
math.LO
null
A sectionally pseudocomplemented poset P is one which has the top element and in which every principal order filter is a pseudocomplemented poset. The sectional pseudocomplements give rise to an implication-like operation on P which coincides with the relative pseudocomplementation if P is relatively psudocomplemented. We characterise this operation and study some elementary properties of upper semilattices, lower semilattices and lattices equipped with this kind of implication. We deal also with a few weaker versions of implication. Sectionally pseudocomplemented lattices have already been studied in the literature.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:25:26 GMT" }, { "version": "v2", "created": "Fri, 25 May 2007 20:15:35 GMT" } ]
2013-01-07T00:00:00
[ [ "C\\=ırulis", "J\\{=}anis", "", "University of Latvia" ] ]
0705.3804
Koji Terashi
Koji Terashi (for the CDF and D0 Collaborations)
Exclusive e+e-, Di-photon and Di-jet Production at the Tevatron
4 pages, To be submitted to the proceedings of the 42nd Rencontres de Moriond - QCD and High Energy Hadronic Interactions, La Thuile, Italy, 17-24 March 2007
null
null
null
hep-ex
null
Results from studies on exclusive production of electron-position pair, di-photon, and di-jet production at CDF in proton-antiproton collisions at the Fermilab Tevatron are presented. The first observation and cross section measurements of exclusive e+e- and di-jet production in hadron-hadron collisions are emphasized.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:42:30 GMT" } ]
2019-08-14T00:00:00
[ [ "Terashi", "Koji", "", "for the CDF and D0 Collaborations" ] ]
0705.3805
Fernando Sols
F. Sols, F. Guinea, and A. H. Castro Neto
Coulomb blockade in graphene nanoribbons
4 pages, 2 figures
Phys. Rev. Lett. 99, 166803 (2007)
10.1103/PhysRevLett.99.166803
null
cond-mat.mes-hall
null
We propose that recent transport experiments revealing the existence of an energy gap in graphene nanoribbons may be understood in terms of Coulomb blockade. Electron interactions play a decisive role at the quantum dots which form due to the presence of necks arising from the roughness of the graphene edge. With the average transmission as the only fitting parameter, our theory shows good agreement with the experimental data.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:30:59 GMT" }, { "version": "v2", "created": "Mon, 22 Oct 2007 14:28:53 GMT" } ]
2009-11-13T00:00:00
[ [ "Sols", "F.", "" ], [ "Guinea", "F.", "" ], [ "Neto", "A. H. Castro", "" ] ]
0705.3806
Oded Regev
Avraham Ben-Aroya, Oded Regev, Ronald de Wolf
A Hypercontractive Inequality for Matrix-Valued Functions with Applications to Quantum Computing and LDCs
This is the full version of a paper that will appear in the proceedings of the IEEE FOCS 08 conference
null
10.1109/FOCS.2008.45
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bonami-Beckner hypercontractive inequality is a powerful tool in Fourier analysis of real-valued functions on the Boolean cube. In this paper we present a version of this inequality for matrix-valued functions on the Boolean cube. Its proof is based on a powerful inequality by Ball, Carlen, and Lieb. We also present a number of applications. First, we analyze maps that encode $n$ classical bits into $m$ qubits, in such a way that each set of $k$ bits can be recovered with some probability by an appropriate measurement on the quantum encoding; we show that if $m<0.7 n$, then the success probability is exponentially small in $k$. This result may be viewed as a direct product version of Nayak's quantum random access code bound. It in turn implies strong direct product theorems for the one-way quantum communication complexity of Disjointness and other problems. Second, we prove that error-correcting codes that are locally decodable with 2 queries require length exponential in the length of the encoded string. This gives what is arguably the first ``non-quantum'' proof of a result originally derived by Kerenidis and de Wolf using quantum information theory, and answers a question by Trevisan.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:23:30 GMT" }, { "version": "v2", "created": "Thu, 14 Aug 2008 16:14:12 GMT" } ]
2016-11-15T00:00:00
[ [ "Ben-Aroya", "Avraham", "" ], [ "Regev", "Oded", "" ], [ "de Wolf", "Ronald", "" ] ]
0705.3807
Christine Kuntscher
Simone Frank, Christine A. Kuntscher, Ivan Gregora, Touru Yamauchi, and Yutaka Ueda
Pressure-induced changes in the optical properties of quasi-one-dimensional $\beta$-Na$_{0.33}$V$_2$O$_5$
7 pages, 5 figures
Phys. Rev. B 76, 075128 (2007)
10.1103/PhysRevB.76.075128
null
cond-mat.str-el
null
The pressure-induced changes in the optical properties of $\beta$-Na$_{0.33}$V$_2$O$_5$ single crystals at room temperature were studied by polarization-dependent Raman and far-infrared reflectivity measurements under high pressure. From the changes in the Raman- and infrared-active phonon modes in the pressure range 9 - 12 GPa a transfer of charge between the different V sites can be inferred. The importance of electron-phonon coupling in the low-pressure regime is discussed.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:20:55 GMT" } ]
2018-02-02T00:00:00
[ [ "Frank", "Simone", "" ], [ "Kuntscher", "Christine A.", "" ], [ "Gregora", "Ivan", "" ], [ "Yamauchi", "Touru", "" ], [ "Ueda", "Yutaka", "" ] ]
0705.3808
Doyoon Kim
Doyoon Kim
Parabolic equations with measurable coefficients in $L_p$-spaces with mixed norms
null
null
null
null
math.AP
null
The unique solvability of parabolic equations in Sobolev spaces with mixed norms is presented. The second order coefficients (except $a^{11}$) are assumed to be only measurable in time and one spatial variable, and VMO in the other spatial variables. The coefficient $a^{11}$ is measurable in one spatial variable and VMO in the other variables.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:11:18 GMT" } ]
2007-05-28T00:00:00
[ [ "Kim", "Doyoon", "" ] ]
0705.3809
Kai Schwenzer
Markus Q. Huber, Reinhard Alkofer, Christian S. Fischer and Kai Schwenzer
The infrared behavior of Landau gauge Yang-Mills theory in d=2, 3 and 4 dimensions
10 pages, 10 figures, version to be published in Phys. Lett. B
Phys.Lett.B659:434-440,2008
10.1016/j.physletb.2007.10.073
null
hep-ph hep-lat hep-th
null
We develop a general power counting scheme for the infrared limit of Landau gauge SU(N) Yang-Mills theory in arbitrary dimensions. Employing a skeleton expansion, we find that the infrared behavior is qualitatively independent of the spacetime dimension d. In the cases d=2, 3 and 4 even the quantitative results for the infrared exponents of the vertices differ only slightly. Therefore, corresponding lattice simulations provide interesting qualitative information for the physical case. We furthermore find that the loop integrals depend only weakly on the numerical values of the IR exponents.
[ { "version": "v1", "created": "Fri, 25 May 2007 16:28:47 GMT" }, { "version": "v2", "created": "Mon, 29 Oct 2007 10:01:28 GMT" } ]
2008-11-26T00:00:00
[ [ "Huber", "Markus Q.", "" ], [ "Alkofer", "Reinhard", "" ], [ "Fischer", "Christian S.", "" ], [ "Schwenzer", "Kai", "" ] ]
0705.3810
Maria Joita M.
Maria Joita
Crossed products of locally C*-algebras and Morita equivalence
25 pages, presented at: ICM 2006, Section "Operator Algebras and Functional Analysis, minor corrections
null
null
null
math.OA math.FA
null
We introduce the notion of strong Morita equivalence for group actions on locally C*-algebras and prove that the crossed products associated with two strongly Morita equivalent continuous inverse limit actions of a locally compact group G on the locally C*-algebras A and B are strongly Morita equivalent. This generalizes a result of F. Combes, Proc. London Math. Soc. 49(1984) and R. E. Curto, P.S. Muhly, D. P. Williams, Proc. Amer. Soc. 90(1984).
[ { "version": "v1", "created": "Fri, 25 May 2007 16:33:50 GMT" }, { "version": "v2", "created": "Tue, 2 Oct 2007 20:14:14 GMT" } ]
2007-10-02T00:00:00
[ [ "Joita", "Maria", "" ] ]
0705.3811
Mikhail Shifman
M. Shifman, A. Yung
Confinement in N=1 SQCD: One Step Beyond Seiberg's Duality
30 pages, 3 figures; v2 a reference added, minor comments added; final version to be published in PRD
Phys.Rev.D76:045005,2007
10.1103/PhysRevD.76.045005
FTPI-MINN-07/18, UMN-TH-2605/07, ITEP-TH-20/07
hep-th hep-ph
null
We consider N=1 supersymmetric quantum chromodynamics (SQCD) with the gauge group U(N_c) and N_c+N quark flavors. N_c flavors are massless; the corresponding squark fields develop (small) vacuum expectation values (VEVs) on the Higgs branch. Extra N flavors are endowed with small (and equal) mass terms. We study this theory through its Seiberg's dual: U(N) gauge theory with N_c +N flavors of "dual quark" fields plus a gauge-singlet mesonic field M. The original theory is referred to as "quark theory" while the dual one is termed "monopole theory." The suggested mild deformation of Seiberg's procedure changes the dynamical regime of the monopole theory from infrared free to asymptotically free at large distances. We show that, upon condensation of the "dual quarks," the dual theory supports non-Abelian flux tubes (strings). Seiberg's duality is extended beyond purely massless states to include light states on both sides. Being interpreted in terms of the quark theory, the monopole-theory flux tubes are supposed to carry chromoelectric fields. The string junctions -- confined monopole-theory monopoles -- can be viewed as "constituent quarks" of the original quark theory. We interpret closed strings as glueballs of the original quark theory. Moreover, there are string configurations formed by two junctions connected by a pair of different non-Abelian strings. These can be considered as constituent quark mesons of the quark theory.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:08:20 GMT" }, { "version": "v2", "created": "Mon, 2 Jul 2007 16:28:02 GMT" } ]
2010-05-27T00:00:00
[ [ "Shifman", "M.", "" ], [ "Yung", "A.", "" ] ]
0705.3812
Ursula Hamenstaedt
Ursula Hamenstaedt
Dynamics of the Teichmueller flow on compact invariant sets
Final version
null
null
null
math.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let Q(S) be the moduli space of area one holomorphic quadratic differentials for an oriented surface S of genus g with m punctures and 3g-3+m>1. We show that the supremum over all compact subsets K of Q(S) of the asymptotic growth rate of the number of periodic orbits of the Teichmueller flow which are contained in K equals h=6g-6+2m. Moreover, h is also the supremum of the topological entropies of the restriction of the Teichmueller flow to compact invariant subsets of Q(S).
[ { "version": "v1", "created": "Fri, 25 May 2007 17:27:29 GMT" }, { "version": "v2", "created": "Thu, 24 Jan 2008 16:15:39 GMT" }, { "version": "v3", "created": "Wed, 14 Jul 2010 10:02:38 GMT" } ]
2010-07-15T00:00:00
[ [ "Hamenstaedt", "Ursula", "" ] ]
0705.3813
Carlos Saavedra Dr
O. Jim\'enez, X. S\'anchez-Lozano, A. Delgado, C. Saavedra
Experimental scheme for unambiguous discrimination of linearly independent symmetric states
null
null
10.1103/PhysRevA.76.062107
null
quant-ph
null
We propose an optimal discrimination scheme for a case of four linearly independent nonorthogonal symmetric quantum states, based on linear optics only. The probability of discrimination is in agreement with the optimal probability for unambiguous discrimination among N symmetric states [Phys. Lett. A \textbf{250}, 223 (1998)]. The experimental setup can be extended for the case of discrimination among $2^M$ nonorthogonal symmetric quantum states.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:28:37 GMT" }, { "version": "v2", "created": "Mon, 28 May 2007 18:27:19 GMT" } ]
2009-11-13T00:00:00
[ [ "Jiménez", "O.", "" ], [ "Sánchez-Lozano", "X.", "" ], [ "Delgado", "A.", "" ], [ "Saavedra", "C.", "" ] ]
0705.3814
Maria-Paola Lombardo
Massimo D'Elia, Francesco Di Renzo, Maria Paola Lombardo
The strongly interacting Quark Gluon Plasma, and the critical behaviour of QCD at imaginary chemical potential
9 pages, 10 figures; one typo fixed, beta value specified
Phys.Rev.D76:114509,2007
10.1103/PhysRevD.76.114509
GEF-TH-13/07
hep-lat hep-ph nucl-th
null
We explore the highly non-perturbative hot region of the QCD phase diagram close to Tc by use of an imaginary chemical potential mu which avoids the sign problem. The number density and the quark number susceptibility are consistent with a critical behaviour associated with the transition line in the negative mu^2 half-plane. We compare the analytic continuation of these results with various phenomenological models, none of which provides a satisfactory description of data, a failure on which we make some comments. These results complement and extend the information obtained via the analysis of the susceptibilities evaluated at zero mu, yielding a simple description of the candidate strongly interacting QGP phase. As a byproduct of our analysis we investigate the Polyakov loop and its hermitian conjugate. Our data offer a vivid evidence of the importance of the complex nature of the functional integral measure, which results in L (mu) ne \bar L(mu) for a real chemical potential.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:36:26 GMT" }, { "version": "v2", "created": "Thu, 7 Jun 2007 17:23:33 GMT" } ]
2008-11-26T00:00:00
[ [ "D'Elia", "Massimo", "" ], [ "Di Renzo", "Francesco", "" ], [ "Lombardo", "Maria Paola", "" ] ]
0705.3815
Brian Rebel
MINOS Collaboration
Measurement of the Atmospheric Muon Charge Ratio at TeV Energies with MINOS
16 pages, 17 figures
Phys.Rev.D76:052003,2007
10.1103/PhysRevD.76.052003
FERMILAB-PUB-07-134-E
hep-ex
null
The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 meters-water-equivalent in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be 1.374 +/- 0.004 (stat.) +0.012 -0.010(sys.). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the two standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3 -- 1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:44:27 GMT" }, { "version": "v2", "created": "Wed, 30 May 2007 18:40:09 GMT" }, { "version": "v3", "created": "Thu, 31 May 2007 15:21:26 GMT" }, { "version": "v4", "created": "Thu, 26 Jul 2007 22:14:36 GMT" } ]
2012-08-27T00:00:00
[ [ "MINOS Collaboration", "", "" ] ]
0705.3816
Harald Merkel
M. Weis, P. Bartsch, D. Baumann, J. Bermuth, A. M. Bernstein, K. Bohinc, R. B\"ohm, M. Ding, M. O. Distler, I. Ewald, J. M. Friedrich, J. Friedrich, M. Kahrau, M. Kohl, K. W. Krygier, A. Liesenfeld, H. Merkel, P. Merle, U. M\"uller, R. Neuhausen, M. M. Pavan, Th. Pospischil, M. Potokar, G. Rosner, H. Schmieden, M. Seimetz, S. \v{S}irca, A. Wagner, Th. Walcher
Separated cross sections in \pi^0 electroproduction at threshold at Q^2 = 0.05 GeV^2/c^2
6 pages, 4 figures
Eur.Phys.J.A38:27-33,2008
10.1140/epja/i2007-10644-6
null
nucl-ex
null
The differential cross sections \sigma_0=\sigma_T+\epsilon \sigma_L, \sigma_{LT}, and \sigma_{TT} of \pi^0 electroproduction from the proton were measured from threshold up to an additional center of mass energy of 40 MeV, at a value of the photon four-momentum transfer of Q^2= 0.05 GeV^2/c^2 and a center of mass angle of \theta=90^\circ. By an additional out-of-plane measurement with polarized electrons \sigma_{LT'} was determined. This showed for the first time the cusp effect above the \pi^+ threshold in the imaginary part of the s-wave. The predictions of Heavy Baryon Chiral Perturbation Theory are in disagreement with these data. On the other hand, the data are somewhat better predicted by the MAID phenomenological model and are in good agreement with the dynamical model DMT.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:37:31 GMT" } ]
2008-11-26T00:00:00
[ [ "Weis", "M.", "" ], [ "Bartsch", "P.", "" ], [ "Baumann", "D.", "" ], [ "Bermuth", "J.", "" ], [ "Bernstein", "A. M.", "" ], [ "Bohinc", "K.", "" ], [ "Böhm", "R.", "" ], [ "Ding", "M.", "" ], [ "Distler", "M. O.", "" ], [ "Ewald", "I.", "" ], [ "Friedrich", "J. M.", "" ], [ "Friedrich", "J.", "" ], [ "Kahrau", "M.", "" ], [ "Kohl", "M.", "" ], [ "Krygier", "K. W.", "" ], [ "Liesenfeld", "A.", "" ], [ "Merkel", "H.", "" ], [ "Merle", "P.", "" ], [ "Müller", "U.", "" ], [ "Neuhausen", "R.", "" ], [ "Pavan", "M. M.", "" ], [ "Pospischil", "Th.", "" ], [ "Potokar", "M.", "" ], [ "Rosner", "G.", "" ], [ "Schmieden", "H.", "" ], [ "Seimetz", "M.", "" ], [ "Širca", "S.", "" ], [ "Wagner", "A.", "" ], [ "Walcher", "Th.", "" ] ]
0705.3817
Pavel A. Ritto Mijangos
P. A. Ritto
Non extensive statistic of Tsallis in the heartbeat of healthy humans
This article has been published in Spanish with minor changes in the text. The abstract shows now the right 'q'
Rev. Mex. Fis. 57(4) (2011) 362-367
null
null
physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is studied the MIT-BIH Normal Sinus Rhythm Database using a statistical technique of analysis, that is based on the Wavelet and Hilbert Transforms. With that technique, it was previously found, that there is a collective and intrinsic dynamical behavior up to a scale of 64 heartbeats. Now it is shown, that using the Biorthogonal wavelet bior3.1 such a behavior reaches the scale 1024. That result confirms, that the circulatory system is out of equilibrium. According to the Statistical Mechanics of Tsallis, and a recent interpretation of G. Wilk et al. respect to the non extensive parameter q, the healthy human being is characterized by q=1.70+/-0.01.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:08:50 GMT" }, { "version": "v2", "created": "Sat, 26 May 2007 17:39:13 GMT" }, { "version": "v3", "created": "Wed, 12 Dec 2007 18:39:46 GMT" }, { "version": "v4", "created": "Tue, 6 Apr 2010 01:44:33 GMT" }, { "version": "v5", "created": "Wed, 10 Aug 2011 05:26:09 GMT" } ]
2011-08-11T00:00:00
[ [ "Ritto", "P. A.", "" ] ]
0705.3818
Johannes Bauer
J. Bauer and A.C. Hewson
Field dependent quasiparticles in a strongly correlated local system II
7 pages, 9 figures
Phys. Rev. B 76 (2007), 035119
10.1103/PhysRevB.76.035119
null
cond-mat.str-el
null
We extend the renormalized quasiparticle description of the symmetric Anderson model in a magnetic field $H$, developed in earlier work, to the non-symmetric model. The renormalized parameters are deduced from the low energy NRG fixed point for arbitrary field values. We find quasiparticle resonance widths, $\tilde\Delta_\sigma(H)$, which depend in general on the spin $\sigma$ as well as $H$. The low temperature static properties can be expressed completely in terms of these parameters, which can also be used as inputs for a renormalized perturbation theory. We show that taking into account repeated quasiparticle scattering gives results for the longitudinal and transverse dynamic spin susceptibilities which are in very good agreement with those obtained from direct NRG calculations.
[ { "version": "v1", "created": "Fri, 25 May 2007 17:51:10 GMT" } ]
2009-11-13T00:00:00
[ [ "Bauer", "J.", "" ], [ "Hewson", "A. C.", "" ] ]
0705.3819
Maria Joita M.
Maria Joita
On Morita equivalence of group actions on locally C*-algebras
11 pages
null
null
null
math.OA math.FA
null
We extend to the context of locally C*-algebras a result of F. Combes [Proc. London Math. Soc. 49(1984), 289-306].
[ { "version": "v1", "created": "Fri, 25 May 2007 18:03:23 GMT" } ]
2007-05-28T00:00:00
[ [ "Joita", "Maria", "" ] ]
0705.3820
Francisco Santos
Oswin Aichholzer, Thomas Hackl, Michael Hoffmann, Clemens Huemer, Attila Por, Francisco Santos, Bettina Speckmann, Birgit Vogtenhuber
Maximizing Maximal Angles for Plane Straight-Line Graphs
15 pages, 14 figures. Apart of minor corrections, some proofs that were omitted in the previous version are now included
In "Algorithms and Data Structures, WADS 2007, Halifax, Canada, August 15-17, 2007", Frank Dehne et al. (Eds.), LNCS 4619, Springer-Verlag, 2007, pp. 458-469
10.1007/978-3-540-73951-7_40
null
cs.CG cs.DM math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let $G=(S, E)$ be a plane straight-line graph on a finite point set $S\subset\R^2$ in general position. The incident angles of a vertex $p \in S$ of $G$ are the angles between any two edges of $G$ that appear consecutively in the circular order of the edges incident to $p$. A plane straight-line graph is called $\phi$-open if each vertex has an incident angle of size at least $\phi$. In this paper we study the following type of question: What is the maximum angle $\phi$ such that for any finite set $S\subset\R^2$ of points in general position we can find a graph from a certain class of graphs on $S$ that is $\phi$-open? In particular, we consider the classes of triangulations, spanning trees, and paths on $S$ and give tight bounds in most cases.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:10:45 GMT" }, { "version": "v2", "created": "Mon, 12 Oct 2009 19:07:20 GMT" } ]
2010-06-15T00:00:00
[ [ "Aichholzer", "Oswin", "" ], [ "Hackl", "Thomas", "" ], [ "Hoffmann", "Michael", "" ], [ "Huemer", "Clemens", "" ], [ "Por", "Attila", "" ], [ "Santos", "Francisco", "" ], [ "Speckmann", "Bettina", "" ], [ "Vogtenhuber", "Birgit", "" ] ]
0705.3821
Gerasim Kokarev
Gerasim Kokarev
On pseudo-harmonic maps in conformal geometry
errors corrected, revised versions of the results, the proof of the factorisation theorem is re-written, references updated, 32 pages
Proc. London Math. Soc. 99 (2009), 168-194.
10.1112/plms/pdn056
null
math.DG math.AP
null
We extend harmonic map techniques to the setting of more general differential equations in conformal geometry. We obtain an extension of Siu's rigidity to Kahler-Weyl geometry and apply the latter to Vaisman's conjecture. Other applications include topological obstructions to the existence of Kahler-Weyl structures. For example, we show that no co-compact lattice in SO(1,n), n>2, can be the fundamental group of a compact Kahler-Weyl manifold of certain type.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:15:36 GMT" }, { "version": "v2", "created": "Fri, 15 Jun 2007 12:44:07 GMT" }, { "version": "v3", "created": "Wed, 7 May 2008 14:18:09 GMT" } ]
2014-02-26T00:00:00
[ [ "Kokarev", "Gerasim", "" ] ]
0705.3822
Christina Sormani
Christina Sormani, Guofang Wei
The Cut-off Covering Spectrum
44 pages, 4 figures; v3 numbered as will be published, minor clarifications of some statements and details added to some proofs, inserted extra background Section 2.1
Transactions of the American Mathematical Society 362 (2010), 2339-2391.
null
null
math.MG math.SP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the $R$ cut-off covering spectrum and the cut-off covering spectrum of a complete length space or Riemannian manifold. The spectra measure the sizes of localized holes in the space and are defined using covering spaces called $\delta$ covers and $R$ cut-off $\delta$ covers. They are investigated using $\delta$ homotopies which are homotopies via grids whose squares are mapped into balls of radius $\delta$. On locally compact spaces, we prove that these new spectra are subsets of the closure of the length spectrum. We prove the $R$ cut-off covering spectrum is almost continuous with respect to the pointed Gromov-Hausdorff convergence of spaces and that the cut-off covering spectrum is also relatively well behaved. This is not true of the covering spectrum defined in our earlier work which was shown to be well behaved on compact spaces. We close by analyzing these spectra on Riemannian manifolds with lower bounds on their sectional and Ricci curvature and their limit spaces.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:25:33 GMT" }, { "version": "v2", "created": "Thu, 1 May 2008 14:21:16 GMT" }, { "version": "v3", "created": "Wed, 17 Sep 2008 12:50:01 GMT" } ]
2010-02-05T00:00:00
[ [ "Sormani", "Christina", "" ], [ "Wei", "Guofang", "" ] ]
0705.3823
Fabio Perroni
Fabio Perroni
A note on toric Deligne-Mumford stacks
Version2: typos corrected; we add sections 6 and 7 where we relate the present work with the paper of Iwanari: arXiv:math/0610548 and that of Fantechi-Mann-Nironi: arXiv:0708.1254. Accepted for publication in the Tohoku Math. J
null
null
null
math.AG
null
We give a new description of the data needed to specify a morphism from a scheme to a toric Deligne-Mumford stack. The description is given in terms of a collection of line bundles and sections which satisfy certain conditions. As applications, we characterize any toric Deligne-Mumford stack as a product of roots of line bundles over the rigidified stack, describe the torus action, describe morphisms between toric Deligne-Mumford stacks with complete coarse moduli spaces in terms of homogeneous polynomials, and compare two different definitions of toric stacks.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:31:50 GMT" }, { "version": "v2", "created": "Tue, 8 Apr 2008 13:11:38 GMT" } ]
2008-04-08T00:00:00
[ [ "Perroni", "Fabio", "" ] ]
0705.3824
Johannes Bauer
J. Bauer and A.C. Hewson
Field dependent quasiparticles in the infinite dimensional Hubbard model
14 pages, 21 figures
Phys. Rev. B 76 (2007), 035118.
10.1103/PhysRevB.76.035118
null
cond-mat.str-el
null
We present dynamical mean field theory (DMFT) results for the local spectral densities of the one- and two-particle response functions for the infinite dimensional Hubbard model in a magnetic field. We look at the different regimes corresponding to half-filling, near half-filling and well away from half-filling, for intermediate and strong values of the local interaction $U$. The low energy results are analyzed in terms of quasiparticles with field dependent parameters. The renormalized parameters are determined by two different methods, both based on numerical renormalization group (NRG) calculations, and we find good agreement. Away from half-filling the quasiparticle weights, $z_\sigma(H)$, differ according to the spin type $\sigma=\uparrow$ or $\sigma=\downarrow$. Using the renormalized parameters, we show that DMFT-NRG results for the local longitudinal and transverse dynamic spin susceptibilities in an arbitrary field can be understood in terms of repeated scattering of these quasiparticles. We also check Luttinger's theorem for the Hubbard model and find it to be satisfied in all parameter regimes and for all values of the magnetic field.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:17:54 GMT" } ]
2009-11-13T00:00:00
[ [ "Bauer", "J.", "" ], [ "Hewson", "A. C.", "" ] ]
0705.3825
Fei Yen
F. Yen, C. dela Cruz, B. Lorenz, E. Galstyan, Y. Y. Sun, M. Gospodinov, and C. W. Chu
Magnetic Phase Diagrams of Multiferroic Hexagonal RMnO3 (R=Er, Yb, Tm, and Ho)
23 pages, 16 figures, to be published in JMR's Aug. focus issue on multiferroics
J. Mater. Research, Volume: 22, #: 8. Pages: 2163-2173 (2007)
10.1557/jmr.2007.0271
null
cond-mat.str-el
null
The magnetic phase diagrams of RMnO3 (R = Er, Yb, Tm, Ho) are investigated up to 14 Tesla via magnetic and dielectric measurements. The stability range of the AFM order below the Neel temperature of the studied RMnO3 extends to far higher magnetic fields than previously assumed. Magnetic irreversibility indicating the presence of a spontaneous magnetic moment is found near 50 K for R=Er, Yb, and Tm. At very low temperatures and low magnetic fields the phase boundary defined by the ordering of the rare earth moments is resolved. The sizable dielectric anomalies observed along all phase boundaries are evidence for strong spin-lattice coupling in the hexagonal RMnO3. In HoMnO3 the strong magnetoelastic distortions are investigated in more detail via magnetostriction experiments up to 14 Tesla. The results are discussed based on existing data on magnetic symmetries and the interactions between the Mn-spins, the rare earth moments, and the lattice.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:40:16 GMT" } ]
2016-06-29T00:00:00
[ [ "Yen", "F.", "" ], [ "Cruz", "C. dela", "" ], [ "Lorenz", "B.", "" ], [ "Galstyan", "E.", "" ], [ "Sun", "Y. Y.", "" ], [ "Gospodinov", "M.", "" ], [ "Chu", "C. W.", "" ] ]
0705.3826
Peter M. Magyar
Peter Magyar
Notes on Schubert classes of a loop group
null
null
null
null
math.RT math.KT
null
In these notes, we survey the homology of the loop group Omega(K) of a compact group K, also known as the affine Grassmannian of a complex loop group. Using the Bott picture of H_*(Omega(K)), the homology algebra or Pontryagin ring, we obtain two new results: A. Factorization of affine Schubert homology classes. B. Definition of affine Schubert polynomials representing the affine Schubert homology classes in all types, in terms similar to ordinary Schubert polynomials.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:45:03 GMT" } ]
2007-05-28T00:00:00
[ [ "Magyar", "Peter", "" ] ]
0705.3827
William P. Minicozzi ii
Tobias H. Colding and William P. Minicozzi II
Width and mean curvature flow
Includes applications to flows by powers of mean curvature
null
null
null
math.DG math.AP math.GT
null
Given a Riemannian metric on a homotopy $n$-sphere, sweep it out by a continuous one-parameter family of closed curves starting and ending at point curves. Pull the sweepout tight by, in a continuous way, pulling each curve as tight as possible yet preserving the sweepout. We show: Each curve in the tightened sweepout whose length is close to the length of the longest curve in the sweepout must itself be close to a closed geodesic. In particular, there are curves in the sweepout that are close to closed geodesics. Finding closed geodesics on the 2-sphere by using sweepouts goes back to Birkhoff in 1917. As an application, we bound from above, by a negative constant, the rate of change of the width for a one-parameter family of convex hypersurfaces that flows by mean curvature. The width is loosely speaking up to a constant the square of the length of the shortest closed curve needed to ``pull over'' $M$. This estimate is sharp and leads to a sharp estimate for the extinction time; cf. [CM1], [CM2] where a similar bound for the rate of change for the two dimensional width is shown for homotopy 3-spheres evolving by the Ricci flow (see also Perelman).
[ { "version": "v1", "created": "Fri, 25 May 2007 18:56:50 GMT" }, { "version": "v2", "created": "Wed, 13 Jun 2007 14:49:09 GMT" } ]
2007-06-13T00:00:00
[ [ "Colding", "Tobias H.", "" ], [ "Minicozzi", "William P.", "II" ] ]
0705.3828
Samir Mathur
Samir D. Mathur
Falling into a black hole
8 pages, 5 figures (this essay received an honorable mention in the 2007 essay competition of the Gravity Research Foundation)
Int.J.Mod.Phys.D17:583-589,2008
10.1142/S0218271808012309
null
hep-th
null
String theory tells us that quantum gravity has a dual description as a field theory (without gravity). We use the field theory dual to ask what happens to an object as it falls into the simplest black hole: the 2-charge extremal hole. In the field theory description the wavefunction of a particle is spread over a large number of `loops', and the particle has a well-defined position in space only if it has the same `position' on each loop. For the infalling particle we find one definition of `same position' on each loop, but there is a different definition for outgoing particles and no canonical definition in general in the horizon region. Thus the meaning of `position' becomes ill-defined inside the horizon.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:57:06 GMT" } ]
2008-11-26T00:00:00
[ [ "Mathur", "Samir D.", "" ] ]
0705.3829
Deirdre Shoemaker
Birjoo Vaishnav, Ian Hinder, Frank Herrmann, Deirdre Shoemaker
Matched Filtering of Numerical Relativity Templates of Spinning Binary Black Holes
null
Phys.Rev.D76:084020,2007
10.1103/PhysRevD.76.084020
null
gr-qc astro-ph
null
Tremendous progress has been made towards the solution of the binary-black-hole problem in numerical relativity. The waveforms produced by numerical relativity will play a role in gravitational wave detection as either test-beds for analytic template banks or as template banks themselves. As the parameter space explored by numerical relativity expands, the importance of quantifying the effect that each parameter has on first the detection of gravitational waves and then the parameter estimation of their sources increases. In light of this, we present a study of equal-mass, spinning binary-black-hole evolutions through matched filtering techniques commonly used in data analysis. We study how the match between two numerical waveforms varies with numerical resolution, initial angular momentum of the black holes and the inclination angle between the source and the detector. This study is limited by the fact that the spinning black-hole-binaries are oriented axially and the waveforms only contain approximately two and a half orbits before merger. We find that for detection purposes, spinning black holes require the inclusion of the higher harmonics in addition to the dominant mode, a condition that becomes more important as the black-hole-spins increase. In addition, we conduct a preliminary investigation of how well a template of fixed spin and inclination angle can detect target templates of arbitrary spin and inclination for the axial case considered here.
[ { "version": "v1", "created": "Fri, 25 May 2007 18:57:53 GMT" }, { "version": "v2", "created": "Sun, 27 May 2007 18:36:30 GMT" } ]
2008-11-26T00:00:00
[ [ "Vaishnav", "Birjoo", "" ], [ "Hinder", "Ian", "" ], [ "Herrmann", "Frank", "" ], [ "Shoemaker", "Deirdre", "" ] ]
0705.3830
Sergey Smirnov
S. Smirnov, D. Bercioux, and M. Grifoni
Bloch's theory in periodic structures with Rashba's spin-orbit interaction
6 pages, 5 figures
Europhysics Letters 80, 27003 (2007)
10.1209/0295-5075/80/27003
null
cond-mat.mes-hall
null
We consider a two-dimensional electron gas with Rashba's spin-orbit interaction and two in-plane potentials superimposed along directions perpendicular to each other. The first of these potentials is assumed to be a general periodic potential while the second one is totally arbitrary. A general form for Bloch's amplitude is found and an eigen-value problem for the band structure of the system is derived. We apply the general result to the two particular cases in which either the second potential represents a harmonic in-plane confinement or it is zero. We find that for a harmonic confinement regions of the Brillouin zone with high polarizations are associated with the ones of large group velocity.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:48:39 GMT" }, { "version": "v2", "created": "Wed, 19 Sep 2007 15:34:36 GMT" } ]
2007-09-19T00:00:00
[ [ "Smirnov", "S.", "" ], [ "Bercioux", "D.", "" ], [ "Grifoni", "M.", "" ] ]
0705.3831
Tomohisa Takimi
Tomohisa Takimi
Relationship between various supersymmetric lattice models
26 pages, no figure, (v3) modified the eq. (3.15) and (3.18) and related statement in the derivation of Sugino model from the Catterall model in the previous version (v2)
JHEP0707:010,2007
10.1088/1126-6708/2007/07/010
RIKEN-TH-99
hep-lat hep-th
null
We comment on the relationships between several supersymmetric lattice models; the ``orbifold lattice theory'' by Cohen-Kaplan-Katz-Unsal (CKKU), lattice regularization of the topological field theory by Sugino and the ``geometrical approach'' by Catterall. We point out that these three models have close relationships; the N =(2,2) model by Catterall [Catterall] and the two-dimensional N = (2,2) lattice theory being similar to Sugino's construction [Sugino] can be derived by appropriate truncation of fields in the two-dimensional N = (4,4) orbifold lattice theory by CKKU [Cohen et al]. Catterall's N = (2,2) description possesses extra degrees of freedom compared to the target N = (2,2) theory. If we remove those extra degrees of freedom in a way keeping supersymmetry on the lattice, Catterall's description reduces to a model of the Sugino type.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:23:18 GMT" }, { "version": "v2", "created": "Sat, 26 May 2007 13:17:08 GMT" }, { "version": "v3", "created": "Tue, 19 Jun 2007 10:26:30 GMT" } ]
2008-11-26T00:00:00
[ [ "Takimi", "Tomohisa", "" ] ]
0705.3832
Christian Beck
Christian Beck
Superstatistics: Theoretical concepts and physical applications
28 pages, 9 figures. To appear in G. Radons et al.(eds): Anomalous Transport: Foundations and Applications (Wiley-VCH, 2007)
null
null
null
cond-mat.stat-mech
null
A review of the superstatistics concept is provided, including various recent applications to complex systems.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:11:40 GMT" } ]
2007-05-28T00:00:00
[ [ "Beck", "Christian", "" ] ]
0705.3833
Rupert Frank
Rafael D. Benguria, Rupert L. Frank, Michael Loss
The sharp constant in the Hardy-Sobolev-Maz'ya inequality in the three dimensional upper half-space
9 pages
null
null
null
math-ph math.AP math.MP
null
It is shown that the sharp constant in the Hardy-Sobolev-Maz'ya inequality on the three dimensional upper half space is given by the Sobolev constant. This is achieved by a duality argument relating the problem to a Hardy-Littlewood-Sobolev type inequality whose sharp constant is determined as well.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:13:10 GMT" } ]
2007-05-28T00:00:00
[ [ "Benguria", "Rafael D.", "" ], [ "Frank", "Rupert L.", "" ], [ "Loss", "Michael", "" ] ]
0705.3834
L\'aszl\'o M. Feh\'er
L\'aszl\'o M. Feh\'er, Zsolt Patakfalvi
The incidence class and the hierarchy of orbits
12 pages
Central European Journal of Mathematics 7 (2009) no 3, 429-441
10.2478/s11533-009-0026-3
null
math.AG math.AT
null
R. Rim\'anyi defined the incidence class of two singularities X and Y as $[X]|_Y$, the restriction of the Thom polynomial of X to Y. He conjectured that (under mild conditions) the incidence is not zero if and only if Y is in the closure of X. Generalizing this notion we define the incidence class of two orbits X and Y of a representation. We give a sufficient condition (positivity) for Y to have the property that the incidence class $[X]|_Y$ is not zero if and only if Y is in the closure of X for any other orbit X. We show that for many interesting cases, e.g. the quiver representations of Dynkin type positivity holds for all orbits. In other words in these cases the incidence classes completely determine the hierarchy of the orbits. We also study the case of singularities where positivity doesn't hold for all orbits.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:18:57 GMT" } ]
2013-06-25T00:00:00
[ [ "Fehér", "László M.", "" ], [ "Patakfalvi", "Zsolt", "" ] ]
0705.3835
James P. Kneller
James P. Kneller, Gail C. McLaughlin, Justin Brockman
Oscillation Effects and Time Variation of the Supernova Neutrino Signal
null
Phys.Rev.D77:045023,2008
10.1103/PhysRevD.77.045023
null
astro-ph
null
The neutrinos detected from the next Galactic core-collapse supernova will contain valuable information on the internal dynamics of the explosion. One mechanism leading to a temporal evolution of the neutrino signal is the variation of the induced neutrino flavor mixing driven by changes in the density profile. With one and two dimensional hydrodynamical simulations we identify the behavior and properties of prominent features of the explosion. Using these results we demonstrate the time variation of the neutrino crossing probabilities due to changes in the MSW neutrino transformations as the star explodes by using the S-matrix - Monte Carlo - approach to neutrino propagation. After adopting spectra for the neutrinos emitted from the proto-neutron star we calculate for a Galactic supernova the evolution of the positron spectra within a water Cerenkov detector and the ratio of charged current to neutral current event rates for a heavy water - SNO like - detector and find that these detector signals are feasible probes of a number of explosion features.
[ { "version": "v1", "created": "Fri, 25 May 2007 19:35:29 GMT" } ]
2008-11-26T00:00:00
[ [ "Kneller", "James P.", "" ], [ "McLaughlin", "Gail C.", "" ], [ "Brockman", "Justin", "" ] ]
0705.3836
Zlatko Tesanovic
Zlatko Tesanovic
Emergence of Cooper pairs, d-wave duality and the phase diagram of cuprate superconductors
6 pages + 2 figures
Nature Physics 4, 408 - 414 (2008)
10.1038/nphys910
null
cond-mat.str-el cond-mat.supr-con
null
BCS theory describes the formation of Cooper pairs and their instant "Bose condensation" into a superconducting state. Helium atoms are preformed bosons and, in addition to their condensed superfluid state, can also form a quantum solid, lacking phase-coherence. Here we show that the fate of Cooper pairs can be more varied than the BCS or helium paradigms. In copper-oxide d-wave superconductors (dSC) Cooper pairs are intrinsically non-local objects, with both center-of-mass and relative motions. As doping decreases, the center-of mass fluctuations force a correlated dSC into a state with enhanced diamagnetism and robust but short-ranged superconducting order. At extreme underdoping, the relative fluctuations take over and two pseudogaps -- ``small'' (charge) and ``large'' (spin) -- emerge naturally from the theory, as Cooper pairs ``disintegrate'' and charge ``detaches'' from spin-singlet bonds. The ensuing ground state(s) are governed by diagonal (mostly antiferromagnetic) rather than by superconducting (off-diagonal) correlations. The theory is used to account for several recent experiments and to draw general conclusions about the phase diagram.
[ { "version": "v1", "created": "Mon, 28 May 2007 15:50:42 GMT" } ]
2008-07-22T00:00:00
[ [ "Tesanovic", "Zlatko", "" ] ]
0705.3837
Liam McAllister
Daniel Baumann, Anatoly Dymarsky, Igor R. Klebanov, Liam McAllister, Paul J. Steinhardt
A Delicate Universe
4 pages, 2 figures
Phys.Rev.Lett.99:141601,2007
10.1103/PhysRevLett.99.141601
null
hep-th astro-ph
null
We investigate whether explicit models of warped D-brane inflation are possible in string compactifications. To this end, we study the potential for D3-brane motion in a warped conifold that includes holomorphically-embedded D7-branes involved in moduli stabilization. The presence of the D7-branes significantly modifies the inflaton potential. We construct an example based on a very simple and symmetric embedding due to Kuperstein, z_1 = constant, in which it is possible to fine-tune the potential so that slow roll inflation can occur. The resulting model is rather delicate: inflation occurs in the vicinity of an inflection point, and the cosmological predictions are extremely sensitive to the precise shape of the potential.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:01:05 GMT" } ]
2008-11-26T00:00:00
[ [ "Baumann", "Daniel", "" ], [ "Dymarsky", "Anatoly", "" ], [ "Klebanov", "Igor R.", "" ], [ "McAllister", "Liam", "" ], [ "Steinhardt", "Paul J.", "" ] ]
0705.3838
Graeme Smith
Graeme Smith
The private classical capacity with a symmetric side channel and its application to quantum cryptography
8 pages, 1 figure
Phys. Rev. A 78, 022306 (2008)
10.1103/PhysRevA.78.022306
null
quant-ph
null
We study the symmetric-side-channel-assisted private capacity of a quantum channel, for which we provide a single-letter formula. This capacity is additive, convex, and, for degradable channels, equal to the unassisted private capacity. While a channel's (unassisted) capacity for for private classical communication may be strictly larger than its quantum capacity, we will show that these capacities are equal for degradable channels, thus demonstrating the equivalence of privacy and quantum coherence in this context. We use these ideas to find new bounds on the key rate of quantum key distribution protocols with one-way classical post-processing. For the Bennett-Brassard-84 (BB84) protocol, our results demonstrate that collective attacks are strictly stronger than individual attacks.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:04:51 GMT" } ]
2008-08-07T00:00:00
[ [ "Smith", "Graeme", "" ] ]
0705.3839
Huajun Huang Dr
Huajun Huang
Some Extensions of Witt's Theorem
null
null
null
null
math.AG math.RT
null
We extend Witt's theorem to several kinds of simultaneous isometries of subspaces. We determine sufficient and necessary conditions for the extension of an isometry of subspaces $\phi:E\to E'$ to an isometry $\phi_V:V\to V'$ that also sends a given subspace to another, or a given self-dual flag to another, or a Witt's decomposition to another and a special self-dual flag to another. We also determine sufficient and necessary conditions for the isometry of generic flags or the simultaneous isometry of (subspace, self-dual flag) pairs.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:05:49 GMT" } ]
2007-05-29T00:00:00
[ [ "Huang", "Huajun", "" ] ]
0705.3840
Markus Wohlgenannt
T. D. Nguyen, J. Rybicki, Y. Sheng, M. Wohlgenannt
Device-spectroscopy of magnetic field effects in a polyfluorene organic light-emitting diode
4 pages, two figures
null
10.1103/PhysRevB.77.035210
null
cond-mat.soft cond-mat.dis-nn
null
We perform charge-induced absorption and electroluminescence spectroscopy in a polyfluorene organic magnetoresistive device. Our experiments allow us to measure the singlet exciton, triplet exciton and polaron densities in a live device under an applied magnetic field, and to distinguish between three different models that were proposed to explain organic magnetoresistance. These models are based on different spin-dependent interactions, namely exciton formation, triplet exciton-polaron quenching and bipolaron formation. We show that the singlet exciton, triplet exciton and polaron densities and conductivity all increase with increasing magnetic field. Our data are inconsistent with the exciton formation and triplet-exciton polaron quenching models.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:06:27 GMT" } ]
2009-11-13T00:00:00
[ [ "Nguyen", "T. D.", "" ], [ "Rybicki", "J.", "" ], [ "Sheng", "Y.", "" ], [ "Wohlgenannt", "M.", "" ] ]
0705.3841
Michael Andreas Schmidt
Michael Andreas Schmidt
Renormalization Group Evolution in the type I + II seesaw model
14 pages, 5 figures; v4: added contribution from missing box diagram with charged leptons to Eqs. (14f,14g) and corrected sign mistakes in (14h). This led to corrections to Eqs. (17,18,B5d,B5e) and third row of Tab. II
Phys.Rev.D76:073010,2007
10.1103/PhysRevD.76.073010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We carefully analyze the renormalization group equations in the type I + II seesaw scenario in the extended standard model (SM) and minimal supersymmetric standard model (MSSM). Furthermore, we present analytic formulae of the mixing angles and phases and discuss the RG effect on the different mixing parameters in the type II seesaw scenario. The renormalization group equations of the angles have a contribution which is proportional to the mass squared difference for a hierarchical spectrum. This is in contrast to the inverse proportionality to the mass squared difference in the effective field theory case.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:07:41 GMT" }, { "version": "v2", "created": "Mon, 22 Oct 2007 16:02:57 GMT" }, { "version": "v3", "created": "Mon, 9 Apr 2012 01:46:11 GMT" }, { "version": "v4", "created": "Sat, 28 May 2022 04:02:13 GMT" } ]
2022-05-31T00:00:00
[ [ "Schmidt", "Michael Andreas", "" ] ]
0705.3842
George Lusztig
G. Lusztig
A survey of total positivity
8 pages
null
null
null
math.RT
null
We survey the history of totally positive matrices and the generalization to Lie groups. We describe a reduction of a bilinear form to a canonical form (generalizing the case of symplectic nondegenerate forms) using ideas from total positivity; we also place this in a Lie group context. We give a short exposition of results of Fock and Goncharov on the study of homomorphisms of the fundamental group of a closed surface into a Lie group.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:11:22 GMT" } ]
2007-05-29T00:00:00
[ [ "Lusztig", "G.", "" ] ]
0705.3843
Michele Trenti
M. Trenti (1) and M. Stiavelli (1 and 2) ((1) STScI, (2) JHU)
Distribution of the very first PopIII stars and their relation to bright z~6 quasars
30 pages, 9 figures, ApJ accepted
Astrophys.J.667:38-48,2007
10.1086/520502
null
astro-ph
null
We discuss the link between dark matter halos hosting the first PopIII stars and the rare, massive, halos that are generally considered to host bright quasars at high redshift z~6. The main question that we intend to answer is whether the super-massive black holes powering these QSOs grew out from the seeds planted by the first intermediate massive black holes created in the universe. This question involves a dynamical range of 10^13 in mass and we address it by combining N-body simulations of structure formation to identify the most massive halos at z~6 with a Monte Carlo method based on linear theory to obtain the location and formation times of the first light halos within the whole simulation box. We show that the descendants of the first ~10^6 Msun virialized halos do not, on average, end up in the most massive halos at z~6, but rather live in a large variety of environments. The oldest PopIII progenitors of the most massive halos at z~6, form instead from density peaks that are on average one and a half standard deviations more common than the first PopIII star formed in the volume occupied by one bright high-z QSO. The intermediate mass black hole seeds planted by the very first PopIII stars at z>40 can easily grow to masses m_BH>10^9.5 Msun by z=6 assuming Eddington accretion with radiative efficiency \epsilon~0.1. Quenching of the black hole accretion is therefore crucial to avoid an overabundance of supermassive black holes at lower redshift. This can be obtained if the mass accretion is limited to a fraction \eta~6*10^{-3} of the total baryon mass of the halo hosting the black hole. The resulting high end slope of the black hole mass function at z=6 is \alpha ~ -3.7, a value within the 1\sigma error bar for the bright end slope of the observed quasar luminosity function at z=6.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:13:20 GMT" } ]
2009-06-23T00:00:00
[ [ "Trenti", "M.", "", "STScI" ], [ "Stiavelli", "M.", "", "1 and 2" ] ]
0705.3844
Jay Hubisz
Csaba Cs\'aki, Jay Hubisz, and Seung J. Lee
Radion Phenomenology in Realistic Warped Space Models
28 pages, 7 figures
Phys.Rev.D76:125015,2007
10.1103/PhysRevD.76.125015
null
hep-ph
null
We investigate the phenomenology of the Randall-Sundrum radion in realistic models of electroweak symmetry breaking with bulk gauge and fermion fields, since the radion may turn out to be the lightest particle in such models. We calculate the coupling of the radion in such scenarios to bulk fermion and gauge modes. Special attention needs to be devoted to the coupling to massless gauge fields (photon, gluon), since it is well known that loop effects may be important for these fields. We also present a detailed explanation of these couplings from the CFT interpretation. We then use these couplings to determine the radion branching fractions and discuss some of the discovery potential of the LHC for the radion. We find that the gamma-gamma signal is enhanced over most of the range of the radion mass over the gamma-gamma signal of a SM Higgs, as long as the RS scale is sufficiently low. However, the signal significance depends strongly on free parameters that characterize the magnitude of bare brane-localized kinetic terms for the massless gauge fields. In the absence of such terms, the signal can be be enhanced over the traditional RS1 models (where all standard model fields are localized on the IR brane), but the signal can also be reduced compared to RS1 if the brane localized terms are sizeable. We also show that for larger radion masses, where the gamma-gamma signal is no longer significant, one can use the usual 4 lepton signal to discover the radion.
[ { "version": "v1", "created": "Sat, 26 May 2007 23:41:54 GMT" } ]
2008-11-26T00:00:00
[ [ "Csáki", "Csaba", "" ], [ "Hubisz", "Jay", "" ], [ "Lee", "Seung J.", "" ] ]
0705.3845
David Brown
David Brown
BSSN in Spherical Symmetry
This is the final version to be published in CQG. It contains much more information and detail than the original version
Class.Quant.Grav.25:205004,2008
10.1088/0264-9381/25/20/205004
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The BSSN (Baumgarte-Shapiro-Shibata-Nakamura) formulation of the Einstein evolution equations is written in spherical symmetry. These equations can be used to address a number of technical and conceptual issues in numerical relativity in the context of a single Schwarzschild black hole. One of the benefits of spherical symmetry is that the numerical grid points can be tracked on a Kruskal--Szekeres diagram. Boundary conditions suitable for puncture evolution of a Schwarzschild black hole are presented. Several results are shown for puncture evolution using a fourth--order finite difference implementation of the equations.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:16:40 GMT" }, { "version": "v2", "created": "Tue, 19 Aug 2008 13:41:13 GMT" } ]
2008-11-26T00:00:00
[ [ "Brown", "David", "" ] ]
0705.3846
John Middleditch
John Middleditch
The SN 1987A Link to Gamma-Ray Bursts
5 pages, 3 figures, contributed talk proceedings for "Supernova 1987A: 20 Years After: Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W. Weiler, and R. McCray, v2: ``Figure 3, right'' on page 4. v3: add "sGRBs offset from EGs" to abstract
AIP Conf.Proc.937:107-111,2007
10.1063/1.2803549
LAUR 06-5685
astro-ph
null
Early measurements of SN 1987A indicate a beam/jet (BJ) which hit polar ejecta (PE) to produce the "Mystery Spot" (MS). The SN flash takes an extra 8 d to hit the MS, and this was confirmed at 2e39 ergs/s in the optical at day 8. A ramp in luminosity starting near day 10 indicates particles from the BJ hitting the PE, with the fastest particles traveling at 0.8 c, and an upper limit for the optical luminosity of the MS of 5e40 ergs/s at day 20. The details of SN 1987A strongly suggest that it resulted from a merger of 2 stellar cores of a common envelope (CE) binary, i.e. a "double-degenerate" (DD)-initiated SN, and is thus the Rosetta Stone for 99% of MSPs in the non-core-collapsed globular clusters, GRBs, and SNe, including all recent nearby SNe except SN 1986J and the more distant SN 2006gy. Without having to blast through the CE of Sk -69 202, it is likely that the BJ would have caused a full, long-soft gamma-ray burst (lGRB) upon hitting the PE, thus DD can produce lGRBs. The typical 0.5 deg collimation of a GRB, over the 22 lt-d from SN 1987A to its PE, produces ~100 s of delay, MATCHING the observed delay of the non-prompt parts of lGRBs. Because DD must be the dominant SN mechanism in elliptical galaxies, where only short, hard GRBs (sGRBs) have been observed, DD without CE or PE must also make sGRBs, thus the initial photon spectrum of 99% of ALL GRBs is KNOWN, & neutron star (NS)-NS mergers may not make GRBs as we know them. Observations of Ia's strongly suggest that these are also DD, implying another systematic effect in Ia Cosmology, as Ia's will appear to be Ic's when viewed from their DD merger poles, given sufficient matter above that lost to core- collapse (otherwise it would just beg the question of what ELSE they could possibly be). There is no need to invent exotica, such as collapsars or hypernovae, to account for GRBs.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:19:34 GMT" }, { "version": "v2", "created": "Wed, 13 Jun 2007 22:38:06 GMT" }, { "version": "v3", "created": "Fri, 29 Jun 2007 21:12:47 GMT" } ]
2009-06-23T00:00:00
[ [ "Middleditch", "John", "" ] ]
0705.3847
Justin F. Vazquez-Poritz
Mirjam Cvetic, Justin F. Vazquez-Poritz
Warped Resolved L^{a,b,c} Cones
28 pages, 4 figures, additional references
Phys.Rev.D77:126003,2008
10.1103/PhysRevD.77.126003
UPR-1181-T, MIFP-07-03
hep-th
null
We construct supergravity solutions describing a stack of D3-branes localized at a point on a blown-up cycle of a resolved L^{a,b,c} cone. The geometry flows from AdS_5 x L^{a,b,c} to AdS_5 x S^5/Z_k. The corresponding quiver gauge theory undergoes an RG flow between two superconformal fixed points, which leads to semi-infinite chains of flows between the various L^{a,b,c} fixed points. The general system is described by a triplet of Heun equations which can each be solved by an expansion with a three-term recursion relation, though there are closed-form solutions for certain cases. This enables us to read off the operators which acquire non-zero vacuum expectation values as the quiver gauge theory flows away from a fixed point.
[ { "version": "v1", "created": "Mon, 28 May 2007 19:53:21 GMT" }, { "version": "v2", "created": "Tue, 5 Feb 2008 17:43:01 GMT" } ]
2008-11-26T00:00:00
[ [ "Cvetic", "Mirjam", "" ], [ "Vazquez-Poritz", "Justin F.", "" ] ]
0705.3848
Yuri Shtemler
A. Virtser, I. Kupershmidt, Yu.M. Shtemler
Statistical Model for Meteorological Elements Based on Local Radiosonde Measurements in Mediterranean Region
6 pages, 7 figures, International Conf. "Fluxes and structures in fluids", Selected Papers, Moscow, 20-23 July, 2005, 350-355
null
null
null
physics.ao-ph physics.data-an
null
A comprehensive statistical model is developed for vertical profiles of the horizontal wind and temperature throughout the troposphere based on several-years radiosonde measurements of strong winds. The profiles measured under quite different atmospheric conditions exhibit qualitative similarity. A proper choice of the reference scales for the wind, temperature and altitude levels allow us to consider the measurement data as realizations of a random process with universal characteristics: means, the basic functions and parameters of standard distributions for transform coefficients of the Principal Component Analysis. The features of the atmospheric conditions are described by statistical characteristics of the wind-temperature ensemble of dimensional reference scales. The model can be useful for air pollution and safety in high-risk areas such as chemical and nuclear plants.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:25:15 GMT" } ]
2007-05-29T00:00:00
[ [ "Virtser", "A.", "" ], [ "Kupershmidt", "I.", "" ], [ "Shtemler", "Yu. M.", "" ] ]
0705.3849
Catalina Lopez-Bastidas
Catalina L\'opez-Bastidas, Jes\'us A. Maytorena and Francisco Mireles
Interplay of the Rashba and Dresselhaus spin-orbit coupling in the optical spin susceptibility of 2D electron systems
null
null
10.1002/pssc.200775941
null
cond-mat.mes-hall
null
We present calculations of the frequency-dependent spin susceptibility tensor of a two-dimensional electron gas with competing Rashba and Dresselhaus spin-orbit interaction. It is shown that the interplay between both types of spin-orbit coupling gives rise to an anisotropic spectral behavior of the spin density response function which is significantly different from that of vanishing Rashba or Dresselhaus case. Strong resonances are developed in the spin susceptibility as a consequence of the angular anisotropy of the energy spin-splitting. This characteristic optical modulable response may be useful to experimentally probe spin accumulation and spin density currents in such systems.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:11:49 GMT" } ]
2015-05-13T00:00:00
[ [ "López-Bastidas", "Catalina", "" ], [ "Maytorena", "Jesús A.", "" ], [ "Mireles", "Francisco", "" ] ]
0705.3850
Christian de Ronde
Christian de Ronde
Understanding Quantum Mechanics Through the Complementary Descriptions Approach
welcome
null
null
null
quant-ph
null
Niels Bohr introduced the concept of complementarity in order to give a general account of quantum mechanics, however he stressed that the idea of complementarity is related to the general dificulty in the formation of human ideas, inherent in the distinction between subject and object. Earlier, we have introduced a development of the concept of complementarity which constitutes a new approach to the interpretation of quantum mechanics. We argue that this development allows a better understanding of some of the paradigmatic interpretational problems of quantum theory. Within the scheme proposed by modal interpretations we analyze the relation between holism and reductionism as well as the problems proposed by Arntzenius and Clifton. We discuss the problem of presupposing the concept of entity within the quantum formalism and bring into stage the concept of faculty as a way to recover the objective character of quantum mechanics.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:30:52 GMT" } ]
2007-05-29T00:00:00
[ [ "de Ronde", "Christian", "" ] ]
0705.3851
Jan Mandel
Deborah H. Glueck, Anis Karimpour-Fard, Jan Mandel, Larry Hunter, Keith E. Muller
Fast computation by block permanents of cumulative distribution functions of order statistics from several populations
21 pages, 3 figures
Communications in Statistics - Theory and Methods 37 (18): 2815-2824 2008
10.1080/03610920802001896
null
math.ST math.PR stat.CO stat.TH
null
The joint cumulative distribution function for order statistics arising from several different populations is given in terms of the distribution function of the populations. The computational cost of the formula in the case of two populations is still exponential in the worst case, but it is a dramatic improvement compared to the general formula by Bapat and Beg. In the case when only the joint distribution function of a subset of the order statistics of fixed size is needed, the complexity is polynomial, for the case of two populations.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:32:53 GMT" } ]
2008-11-27T00:00:00
[ [ "Glueck", "Deborah H.", "" ], [ "Karimpour-Fard", "Anis", "" ], [ "Mandel", "Jan", "" ], [ "Hunter", "Larry", "" ], [ "Muller", "Keith E.", "" ] ]
0705.3852
Peter S. Ozsvath
Peter Ozsvath, Zoltan Szabo
A cube of resolutions for knot Floer homology
55 pages, 24 figures
null
10.1112/jtopol/jtp032
null
math.GT math.SG
null
We develop a skein exact sequence for knot Floer homology, involving singular knots. This leads to an explicit, algebraic description of knot Floer homology in terms of a braid projection of the knot.
[ { "version": "v1", "created": "Fri, 25 May 2007 20:42:54 GMT" } ]
2014-02-26T00:00:00
[ [ "Ozsvath", "Peter", "" ], [ "Szabo", "Zoltan", "" ] ]
0705.3853
Iv\'an Mart\'i-Vidal Mr.
I. Marti-Vidal, J.M.Marcaide, A. Alberdi, J.C. Guirado, L. Lara, M.A. Perez-Torres, E. Ros, M.K. Argo, R.J. Beswick, T.W.B. Muxlow, A. Pedlar, I.I. Shapiro, C.J. Stockdale, R.A. Sramek, K.W. Weiler, and J. Vinko
8.4GHz VLBI observations of SN2004et in NGC6946
Accepted for publication in A&A (22/05/07)
null
10.1051/0004-6361:20077522
null
astro-ph
null
We report on 8.4GHz Very Long Baseline Interferometry (VLBI) observations of the type II-P supernova SN2004et in the spiral galaxy NGC 6946, made on 20 February 2005 (151 days after explosion). The Very Large Array (VLA) flux density was 1.23$\pm$0.07 mJy, corresponding to an isotropic luminosity at 8.4GHz of (4.45$\pm$0.3)$\times10^{25}$ erg s$^{-1}$ Hz$^{-1}$ and a brightness temperature of (1.3$\pm$0.3)$\times10^{8}$ K. We also provide an improved source position, accurate to about 0.5 mas in each coordinate. The VLBI image shows a clear asymmetry. From model fitting of the size of the radio emission, we estimate a minimum expansion velocity of 15,700$\pm$2,000 km s$^{-1}$. This velocity is more than twice the expected mean expansion velocity estimated from a synchrotron self-absorbed emission model, thus suggesting that synchrotron self-absorption is not relevant for this supernova. With the benefit of an optical spectrum obtained 12 days after explosion, we favor an emission model which consists of two hot spots on an underlying expanding shell of width comparable to that of SN 1993J.
[ { "version": "v1", "created": "Mon, 28 May 2007 18:03:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Marti-Vidal", "I.", "" ], [ "Marcaide", "J. M.", "" ], [ "Alberdi", "A.", "" ], [ "Guirado", "J. C.", "" ], [ "Lara", "L.", "" ], [ "Perez-Torres", "M. A.", "" ], [ "Ros", "E.", "" ], [ "Argo", "M. K.", "" ], [ "Beswick", "R. J.", "" ], [ "Muxlow", "T. W. B.", "" ], [ "Pedlar", "A.", "" ], [ "Shapiro", "I. I.", "" ], [ "Stockdale", "C. J.", "" ], [ "Sramek", "R. A.", "" ], [ "Weiler", "K. W.", "" ], [ "Vinko", "J.", "" ] ]
0705.3854
Igor Moskalenko
I. V. Moskalenko (Stanford), T. A. Porter (UCSC), M. A. Malkov, P. H. Diamond (UCSD)
Hadronic Gamma Rays from Supernova Remnants
4 pages, 3 figures. Contribution to the 30th ICRC, Merida, Mexico, 2007 (final version)
Proc. 30th ICRC (Merida), 2, 763-766 (2007)
null
null
astro-ph
null
A gas cloud near a supernova remnant (SNR) provides a target for pp-collisions leading to subsequent gamma-ray emission through neutral pion decay. The assumption of a power-law ambient spectrum of accelerated particles with index near -2 is usually built into models predicting the spectra of very-high energy (VHE) gamma-ray emission from SNRs. However, if the gas cloud is located at some distance from the SNR shock, this assumption is not necessarily correct. In this case, the particles which interact with the cloud are those leaking from the shock and their spectrum is approximately monoenergetic with the injection energy gradually decreasing as the SNR ages. In the GLAST energy range the gamma-ray spectrum resulting from particle interactions with the gas cloud will be flatter than expected, with the cutoff defined by the pion momentum distribution in the laboratory frame. We evaluate the flux of particles escaping from a SNR shock and apply the results to the VHE diffuse emission detected by the HESS at the Galactic centre.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:17:16 GMT" }, { "version": "v2", "created": "Wed, 15 Aug 2007 01:08:26 GMT" } ]
2009-02-25T00:00:00
[ [ "Moskalenko", "I. V.", "", "Stanford" ], [ "Porter", "T. A.", "", "UCSC" ], [ "Malkov", "M. A.", "", "UCSD" ], [ "Diamond", "P. H.", "", "UCSD" ] ]
0705.3855
Gijs Roelofs
G.H.A. Roelofs, P.J. Groot (Nijmegen), G.F. Benedict, B.E. McArthur (U. Texas, Austin), D. Steeghs (CfA/Warwick), L. Morales-Rueda (Nijmegen), T.R. Marsh (Warwick), and G. Nelemans (Nijmegen)
HST/FGS Parallaxes of AM CVn Stars and Astrophysical Consequences
Accepted for publication in ApJ
null
10.1086/520491
null
astro-ph
null
We present absolute parallaxes and relative proper motions for five AM CVn stars, which we obtained using the Fine Guidance Sensors on board the Hubble Space Telescope. Our parallax measurements translate into distances d(AM CVn)=606+135-93 pc, d(HP Lib)=197+14-12 pc, d(CR Boo)=337+44-35 pc, d(V803 Cen)=347+32-27 pc, and d(GP Com)=75+2-2 pc. From these distances we estimate the space density of AM CVn stars and suggest that previous estimates have been too high by about an order of magnitude. We also infer the mass accretion rates which allows us to constrain the masses of the donor stars, and we show that relatively massive, semi-degenerate donor stars are favored in all systems except GP Com. Finally, we give updated estimates for their gravitational-wave signals, relevant for future space missions such as the proposed Laser Interferometer Space Antenna (LISA), based on their distances and the inferred masses of the binary components. We show that all systems but GP Com are excellent candidates for detection with LISA.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:19:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Roelofs", "G. H. A.", "", "Nijmegen" ], [ "Groot", "P. J.", "", "Nijmegen" ], [ "Benedict", "G. F.", "", "U. Texas, Austin" ], [ "McArthur", "B. E.", "", "U. Texas, Austin" ], [ "Steeghs", "D.", "", "CfA/Warwick" ], [ "Morales-Rueda", "L.", "", "Nijmegen" ], [ "Marsh", "T. R.", "", "Warwick" ], [ "Nelemans", "G.", "", "Nijmegen" ] ]
0705.3856
Igor Moskalenko
Igor V. Moskalenko (Stanford), Troy A. Porter (UCSC)
Gamma-ray albedo of the moon
4 pages, 3 figures. Contribution to the 30th ICRC, Merida, Mexico, 2007 (final version)
Proc. 30th ICRC (Merida), 2, 759-762 (2007)
null
null
astro-ph
null
We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma rays from the Moon is very steep with an effective cutoff around 4 GeV (600 MeV for the inner part of the Moon disc). Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalisation; this makes it a useful "standard candle" for gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo gamma rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:46:29 GMT" }, { "version": "v2", "created": "Wed, 15 Aug 2007 00:52:30 GMT" } ]
2009-02-25T00:00:00
[ [ "Moskalenko", "Igor V.", "", "Stanford" ], [ "Porter", "Troy A.", "", "UCSC" ] ]
0705.3857
Niels Martin M{\o}ller
Niels Martin Moller
Extremal metrics for spectral functions of Dirac operators in even and odd dimensions
45 pages; title and content edited to reflect subsequent related work
Adv. Math. 229 (2012), no. 2, 1001--1046. MR2855085
10.1016/j.aim.2011.10.012
null
math.SP math.DG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let (M^n, g) be a closed smooth Riemannian spin manifold and denote by D its Atiyah-Singer-Dirac operator. We study the variation of Riemannian metrics for the zeta function and functional determinant of D^2, and prove finiteness of the Morse index at stationary metrics, and local extremality at such metrics under general, i.e. not only conformal, change of metrics. In even dimensions, which is also a new case for the conformal Laplacian, the relevant stability operator is of log-polyhomogeneous pseudodifferential type, and we prove new results of independent interest, on the spectrum for such operators. We use this to prove local extremality under variation of the Riemannian metric, which in the important example when (M^n, g) is the round n-sphere, gives a partial verification of Branson's conjecture on the pattern of extremals. Thus det(D^2) has a local (max, max, min, min) when the dimension is (4k, 4k + 1, 4k + 2, 4k + 3), respectively.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:54:30 GMT" }, { "version": "v2", "created": "Fri, 21 Sep 2007 14:58:48 GMT" }, { "version": "v3", "created": "Tue, 1 Sep 2009 04:07:55 GMT" } ]
2019-03-13T00:00:00
[ [ "Moller", "Niels Martin", "" ] ]
0705.3858
Yong-il Shin
Y. Shin, C. H. Schunck, A. Schirotzek, W. Ketterle
Tomographic RF Spectroscopy of a Trapped Fermi Gas at Unitarity
null
Phys. Rev. Lett. 99, 090403 (2007)
10.1103/PhysRevLett.99.090403
null
cond-mat.other cond-mat.soft
null
We present spatially resolved radio-frequency spectroscopy of a trapped Fermi gas with resonant interactions and observe a spectral gap at low temperatures. The spatial distribution of the spectral response of the trapped gas is obtained using in situ phase-contrast imaging and 3D image reconstruction. At the lowest temperature, the homogeneous rf spectrum shows an asymmetric excitation line shape with a peak at 0.48(4)$\epsilon_F$ with respect to the free atomic line, where $\epsilon_F$ is the local Fermi energy.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:51:30 GMT" } ]
2009-11-13T00:00:00
[ [ "Shin", "Y.", "" ], [ "Schunck", "C. H.", "" ], [ "Schirotzek", "A.", "" ], [ "Ketterle", "W.", "" ] ]
0705.3859
George Stephans
G. S. F. Stephans (for the PHOBOS Collaboration)
Systematics of Soft Particle Production at RHIC: Lessons from PHOBOS
4 pages, 3 figures, Proceedings of XLIInd Rencontres de Moriond
null
null
null
nucl-ex
null
The PHOBOS experiment has measured the properties of particle production in heavy ion collisions between sqrt(s_NN) of 20 and 200 GeV. The dependencies of charged particle yield on energy, system size, and both longitudinal and transverse momentum have been determined over close to the full kinematic range. Identified charged particles emitted near mid-rapidity have been studied over about 2 orders of magnitude in transverse momentum. This broad data set was found to be characterized by a small number of simple scalings which factorize to a surprising degree. This study has recently been extended by the addition of new data for Cu+Cu as well as new analyses of Au+Au data, including more peripheral collisions. In addition, the exploration of global properties has been expanded with the use of new techniques, including two-particle correlations, more sensitive searches for rare events, and more detailed studies of particles emitted at very forward rapidity. The characteristics of particle production which are revealed by this extensive data set will be described along with the implications for future data from the LHC.
[ { "version": "v1", "created": "Fri, 25 May 2007 21:52:46 GMT" } ]
2007-05-29T00:00:00
[ [ "Stephans", "G. S. F.", "", "for the PHOBOS Collaboration" ] ]
0705.3860
Kelly McKinnie
Kelly McKinnie
Indecomposable p-algebras and Galois subfields in generic abelian crossed products
21 pages
null
null
null
math.RA
null
Let F be a Henselian valued field with char(F) = p and D a semi-ramified, "not strongly degenerate" p-algebra. We show that all Galois subfields of D are inertial. Using this as a tool we study generic abelian crossed product p-algebras, proving among other things that the noncyclic generic abelian crossed product p-algebras defined by non-degenerate matrices are indecomposable p-algebras. To construct examples of these indecomposable p-algebras with exponent p and large index we study the relationship between degeneracy in matrices defining abelian crossed products and torsion in CH^2 of Severi-Brauer varieties.
[ { "version": "v1", "created": "Fri, 25 May 2007 22:13:18 GMT" } ]
2007-05-29T00:00:00
[ [ "McKinnie", "Kelly", "" ] ]
0705.3861
Igor Shparlinski
A. C. Cojocaru and I. E. Shparlinski
Distribution of Farey Fractions in Residue Classes and Lang--Trotter Conjectures on Average
null
null
null
null
math.NT
null
We prove that the set of Farey fractions of order $T$, that is, the set $\{\alpha/\beta \in \Q : \gcd(\alpha, \beta) = 1, 1 \le \alpha, \beta \le T\}$, is uniformly distributed in residue classes modulo a prime $p$ provided $T \ge p^{1/2 +\eps}$ for any fixed $\eps>0$. We apply this to obtain upper bounds for the Lang--Trotter conjectures on Frobenius traces and Frobenius fields ``on average'' over a one-parametric family of elliptic curves.
[ { "version": "v1", "created": "Fri, 25 May 2007 22:14:57 GMT" } ]
2007-05-29T00:00:00
[ [ "Cojocaru", "A. C.", "" ], [ "Shparlinski", "I. E.", "" ] ]
0705.3862
Francisco Fernandez Dr.
Paolo Amore, Francisco M. Fernandez
Rational Approximation for Two-Point Boundary value problems
13 pages, 1 figure
null
null
null
math-ph math.MP
null
We propose a method for the treatment of two--point boundary value problems given by nonlinear ordinary differential equations. The approach leads to sequences of roots of Hankel determinants that converge rapidly towards the unknown parameter of the problem. We treat several problems of physical interest: the field equation determining the vortex profile in a Ginzburg--Landau effective theory, the fixed--point equation for Wilson's exact renormalization group, a suitably modified Wegner--Houghton's fixed point equation in the local potential approximation, a Riccati equation, and the Thomas--Fermi equation. We consider two models where the approach does not apply in order to show the limitations of our Pad\'{e}--Hankel approach.
[ { "version": "v1", "created": "Fri, 25 May 2007 22:49:10 GMT" } ]
2007-05-29T00:00:00
[ [ "Amore", "Paolo", "" ], [ "Fernandez", "Francisco M.", "" ] ]
0705.3863
Chenggang Zhou
Chenggang Zhou, D. P. Landau, T. C. Schulthess
Monte Carlo simulations of ${\rm Rb_2MnF_4}$, a classical Heisenberg antiferromagnet in two-dimensions with dipolar interaction
13 pages 18 figures
Phys. Rev. B 76, 024433 (2007)
10.1103/PhysRevB.76.024433
null
cond-mat.stat-mech
null
We study the phase diagram of a quasi-two dimensional magnetic system ${\rm Rb_2MnF_4}$ with Monte Carlo simulations of a classical Heisenberg spin Hamiltonian which includes the dipolar interactions between ${\rm Mn}^{2+}$ spins. Our simulations reveal an Ising-like antiferromagnetic phase at low magnetic fields and an XY phase at high magnetic fields. The boundary between Ising and XY phases is analyzed with a recently proposed finite size scaling technique and found to be consistent with a bicritical point at T=0. We discuss the computational techniques used to handle the weak dipolar interaction and the difference between our phase diagram and the experimental results.
[ { "version": "v1", "created": "Fri, 25 May 2007 23:03:24 GMT" } ]
2009-11-13T00:00:00
[ [ "Zhou", "Chenggang", "" ], [ "Landau", "D. P.", "" ], [ "Schulthess", "T. C.", "" ] ]
0705.3864
Alexander Khitun
A. Khitun, M. Bao, J-Y. Lee, K. L. Wang D.W. Lee, S. Wang, and Igor V. Roshchin
Inductively Coupled Circuits with Spin Wave Bus for Information Processing
null
null
null
null
cond-mat.other
null
We describe a new approach to logic devices interconnection by the inductive coupling via a ferromagnetic film. The information among the distant devices is transmitted in a wireless manner via a magnetic field produced by spin waves propagating in the ferromagnetic film, referred to as the spin wave bus. As an alternative approach to the transistor-based architecture, logic circuits with spin wave bus do not use charge as an information carrier. A bit of information can be encoded into the phase or the amplitude of the spin wave signal. We present experimental data demonstrating inductive coupling through the 100nm thick NiFe and CoFe films at room temperature. The performance of logic circuits with spin wave bus is illustrated by numerical modeling based on the experimental data. Potentially, logic circuits with spin wave bus may resolve the interconnect problem and provide "wireless" read-in and read-out. Another expected benefit is in the enhanced logic functionality. A set of NOT, AND, and OR logic gates can be realized in one device structure. The coupling between the circuits and the spin wave bus can be controlled. We present the results of numerical simulations showing the controllable switching of a bi-stable logic cell inductively coupled to the spin wave bus. The shortcomings and limitations of circuits with spin wave bus are also discussed.
[ { "version": "v1", "created": "Fri, 25 May 2007 23:34:31 GMT" } ]
2007-05-29T00:00:00
[ [ "Khitun", "A.", "" ], [ "Bao", "M.", "" ], [ "Lee", "J-Y.", "" ], [ "Lee", "K. L. Wang D. W.", "" ], [ "Wang", "S.", "" ], [ "Roshchin", "Igor V.", "" ] ]
0705.3865
Alessandro Baldi
A. Baldi (1), S. Ettori (2), P. Mazzotta (1 and 3), P. Tozzi (4 and 5), S. Borgani (4, 5 and 6) ((1) Harvard-Smithsonian Center for Astrophysics, (2) INAF - Osservatorio Astronomico di Bologna, (3) Universita' di Roma "Tor Vergata" - Dip. di Fisica, (4) INAF - Osservatorio Astronomico di Trieste, (5) INFN - Sez. di Trieste (6) Universita' di Trieste - Dip. di Fisica)
A Chandra archival study of the temperature and metal abundance profiles in hot Galaxy Clusters at 0.1 < z < 0.3
12 pages, 6 figures, Accepted for publication by the Astrophysical Journal
Astrophys.J.666:835-845,2007
10.1086/520505
null
astro-ph
null
We present the analysis of the temperature and metallicity profiles of 12 galaxy clusters in the redshift range 0.1--0.3 selected from the Chandra archive with at least ~20,000 net ACIS counts and kT>6 keV. We divide the sample between 7 Cooling-Core (CC) and 5 Non-Cooling-Core (NCC) clusters according to their central cooling time. We find that single power-laws can describe properly both the temperature and metallicity profiles at radii larger than 0.1 r_180 in both CC and NCC systems, showing the NCC objects steeper profiles outwards. A significant deviation is only present in the inner 0.1 r_180. We perform a comparison of our sample with the De Grandi & Molendi BeppoSAX sample of local CC and NCC clusters, finding a complete agreement in the CC cluster profile and a marginally higher value (at ~1sigma) in the inner regions of the NCC clusters. The slope of the power-law describing kT(r) within 0.1 r_180 correlates strongly with the ratio between the cooling time and the age of the Universe at the cluster redshift, being the slope >0 and tau_c/tau_age<=0.6 in CC systems.
[ { "version": "v1", "created": "Fri, 25 May 2007 23:57:37 GMT" } ]
2009-06-23T00:00:00
[ [ "Baldi", "A.", "", "1 and 3" ], [ "Ettori", "S.", "", "1 and 3" ], [ "Mazzotta", "P.", "", "1 and 3" ], [ "Tozzi", "P.", "", "4 and\n 5" ], [ "Borgani", "S.", "", "4, 5 and 6" ] ]
0705.3866
Alessio Marrani
S.Ferrara and A.Marrani
N=8 non-BPS Attractors, Fixed Scalars and Magic Supergravities
1+25 pages, 4 Tables, no figures; v2: minor changes and corrections, Ref. added
Nucl.Phys.B788:63-88,2008
10.1016/j.nuclphysb.2007.07.028
CERN-PH-TH/2007-090, UCLA/07/TEP/14
hep-th
null
We analyze the Hessian matrix of the black hole potential of N=8, d=4 supergravity, and determine its rank at non-BPS critical points, relating the resulting spectrum to non-BPS solutions (with non-vanishing central charge) of N=2, d=4 magic supergravities and their ``mirror'' duals. We find agreement with the known degeneracy splitting of N=2 non-BPS spectrum of generic special Kahler geometries with cubic holomorphic prepotential. We also relate non-BPS critical points with vanishing central charge in N=2 magic supergravities to a particular reduction of the N=8, 1/8-BPS critical points.
[ { "version": "v1", "created": "Sat, 26 May 2007 00:47:07 GMT" }, { "version": "v2", "created": "Mon, 11 Jun 2007 15:55:29 GMT" } ]
2008-11-26T00:00:00
[ [ "Ferrara", "S.", "" ], [ "Marrani", "A.", "" ] ]
0705.3867
Michael R. Peterson
Michael R. Peterson, B. Sriram Shastry, and Jan O. Haerter
Thermoelectric effects in a strongly correlated model for Na$_x$CoO$_2$
16 pages, 10 figures, color version available at http://physics.ucsc.edu/~peterson/mrpeterson-condmat-NCO.pdf. V.2 has fixed minor typos in Eq. 11, 19, 25, and 26. V.3 is a color version
Phys. Rev. B 76, 165118 (2007) (14 pages)
10.1103/PhysRevB.76.165118
null
cond-mat.str-el cond-mat.mtrl-sci
null
Thermal response functions of strongly correlated electron systems are of appreciable interest to the larger scientific community both theoretically and technologically. Here we focus on the infinitely correlated t-J model on a geometrically frustrated two-dimensional triangular lattice. Using exact diagonalization on a finite sized system we calculate the dynamical thermal response functions in order to determine the thermopower, Lorenz number, and dimensionless figure of merit. The dynamical thermal response functions is compared to the infinite frequency limit and shown to be very weak functions of frequency, hence, establishing the validity of the high frequency formalism recently proposed by Shastry for the thermopower, Lorenz number, and the dimensionless figure of merit. Further, the thermopower is demonstrated to have a low to mid temperature enhancement when the sign of the hopping parameter $t$ is switched from positive to negative for the geometrically frustrated lattice considered.
[ { "version": "v1", "created": "Sat, 26 May 2007 00:50:35 GMT" }, { "version": "v2", "created": "Wed, 6 Jun 2007 19:33:45 GMT" }, { "version": "v3", "created": "Thu, 7 Jun 2007 21:33:10 GMT" } ]
2009-11-13T00:00:00
[ [ "Peterson", "Michael R.", "" ], [ "Shastry", "B. Sriram", "" ], [ "Haerter", "Jan O.", "" ] ]
0705.3868
Melvin Leok
Taeyoung Lee, Melvin Leok, N. Harris McClamroch
Discrete Control Systems
20 pages, 7 figures. Invited article for the Springer Encyclopedia of Complexity and System Science
null
null
null
math.OC
null
Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete flow remains on the manifold on which the continuous system evolves, an important property in the case of rigid-body dynamics. In nonlinear control, one typically relies on differential geometric and dynamical systems techniques to prove properties such as stability, controllability, and optimality. More generally, the geometric structure of such systems plays a critical role in the nonlinear analysis of the corresponding control problems. Despite the critical role of geometry and mechanics in the analysis of nonlinear control systems, nonlinear control algorithms have typically been implemented using numerical schemes that ignore the underlying geometry. The field of discrete control system aims to address this deficiency by restricting the approximation to choice of a discrete-time model, and developing an associated control theory that does not introduce any additional approximation. In particular, this involves the construction of a control theory for discrete-time models based on geometric integrators that yields numerical implementations of nonlinear and geometric control algorithms that preserve the crucial underlying geometric structure.
[ { "version": "v1", "created": "Sat, 26 May 2007 04:14:23 GMT" } ]
2007-05-29T00:00:00
[ [ "Lee", "Taeyoung", "" ], [ "Leok", "Melvin", "" ], [ "McClamroch", "N. Harris", "" ] ]
0705.3869
Eugene Shakhnovich
Konstantin Zeldovich, Peiqiu Chen, Boris Shakhnovich, Eugene Shakhnovich
A first-principles model of early evolution: Emergence of gene families, species and preferred protein folds
In press, PLoS Computational Biology
null
10.1371/journal.pcbi.0030139
null
q-bio.BM q-bio.PE
null
In this work we develop a microscopic physical model of early evolution, where phenotype,organism life expectancy, is directly related to genotype, the stability of its proteins in their native conformations which can be determined exactly in the model. Simulating the model on a computer, we consistently observe the Big Bang scenario whereby exponential population growth ensues as soon as favorable sequence-structure combinations (precursors of stable proteins) are discovered. Upon that, random diversity of the structural space abruptly collapses into a small set of preferred proteins. We observe that protein folds remain stable and abundant in the population at time scales much greater than mutation or organism lifetime, and the distribution of the lifetimes of dominant folds in a population approximately follows a power law. The separation of evolutionary time scales between discovery of new folds and generation of new sequences gives rise to emergence of protein families and superfamilies whose sizes are power-law distributed, closely matching the same distributions for real proteins. On the population level we observe emergence of species, subpopulations which carry similar genomes. Further we present a simple theory that relates stability of evolving proteins to the sizes of emerging genomes. Together, these results provide a microscopic first principles picture of how first gene families developed in the course of early evolution
[ { "version": "v1", "created": "Sat, 26 May 2007 02:26:55 GMT" } ]
2015-05-13T00:00:00
[ [ "Zeldovich", "Konstantin", "" ], [ "Chen", "Peiqiu", "" ], [ "Shakhnovich", "Boris", "" ], [ "Shakhnovich", "Eugene", "" ] ]
0705.3870
Andy O'Bannon
Andreas Karch and Andy O'Bannon
Metallic AdS/CFT
19 pages, no figures; v2 added two references, clarified discussion in section 3
JHEP 0709:024,2007
10.1088/1126-6708/2007/09/024
null
hep-th
null
We use the AdS/CFT correspondence to compute the conductivity of massive N=2 hypermultiplet fields at finite baryon number density in an N=4 SU(N_c) super-Yang-Mills theory plasma in the large N_c, large 't Hooft coupling limit. The finite baryon density provides charge carriers analogous to electrons in a metal. An external electric field then induces a finite current which we determine directly. Our result for the conductivity is good for all values of the mass, external field and density, modulo statements about the yet-incomplete phase diagram. In the appropriate limits it agrees with known results obtained from analyzing small fluctuations around equilibrium. For large mass, where we expect a good quasi-particle description, we compute the drag force on the charge carriers and find that the answer is unchanged from the zero density case. Our method easily generalizes to a wide class of systems of probe branes in various backgrounds.
[ { "version": "v1", "created": "Sat, 26 May 2007 03:23:15 GMT" }, { "version": "v2", "created": "Mon, 10 Sep 2007 23:44:00 GMT" } ]
2009-04-17T00:00:00
[ [ "Karch", "Andreas", "" ], [ "O'Bannon", "Andy", "" ] ]
0705.3871
S. Q. Wu
Qing-Quan Jiang, Shuang-Qing Wu, Xu Cai
Anomalies and de Sitter radiation from the generic black holes in de Sitter spaces
14 pages without figure, use elsart.cls, to appear in Phys.Lett.B
Phys.Lett.B651:65-70,2007
10.1016/j.physletb.2007.06.003
null
hep-th gr-qc
null
Robinson-Wilczek's recent work shows that, the energy momentum tensor flux required to cancel gravitational anomaly at the event horizon of a Schwarzschild-type black hole has an equivalent form to that of a (1+1)-dimensional blackbody radiation at the Hawking temperature. Motivated by their work, Hawking radiation from the cosmological horizons of the general Schwarzschild-de Sitter and Kerr-de Sitter black holes, has been studied by the method of anomaly cancellation. The result shows that the absorbing gauge current and energy momentum tensor fluxes required to cancel gauge and gravitational anomalies at the cosmological horizon are precisely equal to those of Hawking radiation from it. It should be emphasized that the effective field theory for generic black holes in de Sitter spaces should be formulated within the region between the event horizon (EH) and the cosmological horizon (CH), to integrate out the classically irrelevant ingoing modes at the EH and the classically irrelevant outgoing modes at the CH, respectively.
[ { "version": "v1", "created": "Sat, 26 May 2007 04:00:49 GMT" } ]
2008-11-26T00:00:00
[ [ "Jiang", "Qing-Quan", "" ], [ "Wu", "Shuang-Qing", "" ], [ "Cai", "Xu", "" ] ]
0705.3872
Brent Walker
Brent Walker, Nicola Marzari, and Carla Molteni
In-plane structure and ordering at liquid sodium surfaces and interfaces from ab initio molecular dynamics
null
null
10.1063/1.2781388
null
cond-mat.mtrl-sci
null
Atoms at liquid metal surfaces are known to form layers parallel to the surface. We analyze the two-dimensional arrangement of atoms within such layers at the surface of liquid sodium, using ab initio molecular dynamics (MD) simulations based on density functional theory. Nearest neighbor distributions at the surface indicate mostly 5-fold coordination, though there are noticeable fractions of 4-fold and 6-fold coordinated atoms. Bond angle distributions suggest a movement toward the angles corresponding to a six-fold coordinated hexagonal arrangement of the atoms as the temperature is decreased towards the solidification point. We rationalize these results with a distorted hexagonal order at the surface, showing a mixture of regions of five and six-fold coordination. The liquid surface results are compared with classical MD simulations of the liquid surface, with similar effects appearing, and with ab initio MD simulations for a model solid-liquid interface, where a pronounced shift towards hexagonal ordering is observed as the temperature is lowered.
[ { "version": "v1", "created": "Sat, 26 May 2007 04:36:54 GMT" } ]
2009-11-13T00:00:00
[ [ "Walker", "Brent", "" ], [ "Marzari", "Nicola", "" ], [ "Molteni", "Carla", "" ] ]
0705.3873
Michael H. L. S. Wang
M.H.L.S. Wang (for the D0 and CDF Collaborations)
Top Quark Mass Measurements at the Tevatron and the Standard Model Fits
Presented at the 2007 Moriond-QCD conference
null
null
null
hep-ex
null
New measurements of the top quark mass from the Tevatron are presented. Combined with previous results, they yield a preliminary new world average of Mtop=170.9+-1.1(stat)+-1.5(syst)GeV/c**2 and impose new constraints on the mass of the Higgs boson.
[ { "version": "v1", "created": "Sat, 26 May 2007 04:59:26 GMT" } ]
2019-08-14T00:00:00
[ [ "Wang", "M. H. L. S.", "", "for the D0 and CDF Collaborations" ] ]
0705.3874
Ashoke Sen
Ashoke Sen
Two Centered Black Holes and N=4 Dyon Spectrum
LaTeX file, 12 pages; v3: added footnote 2 regarding overall sign of the index, expanded footnote 3, added references
JHEP 0709:045,2007
10.1088/1126-6708/2007/09/045
null
hep-th
null
The exact spectrum of dyons in a class of N=4 supersymmetric string theories is known to change discontinuously across walls of marginal stability. We show that the change in the degeneracy across the walls of marginal stability can be accounted for precisely by the entropy of two centered small black holes which disappear as we cross the walls of marginal stability.
[ { "version": "v1", "created": "Sun, 27 May 2007 06:03:43 GMT" }, { "version": "v2", "created": "Thu, 12 Jul 2007 14:13:27 GMT" }, { "version": "v3", "created": "Wed, 25 Jul 2007 04:19:46 GMT" } ]
2009-04-17T00:00:00
[ [ "Sen", "Ashoke", "" ] ]
0705.3875
Qiang Zhang
Qiang Zhang, Xiuping Xie, Hiroki Takesue, Sae Woo Nam, Carsten Langrock, Martin Fejer, Yoshihisa Yamamoto
Correlated photon-pair generation in reverse-proton-exchange PPLN waveguides with integrated mode demultiplexer at 10 GHz clock
6 pages, 4 figures, presented at 2007 CLEO conference
Opt. Express. 15, 10288 (2007)
10.1364/OE.15.010288
null
quant-ph
null
We report 10-ps correlated photon pair generation in periodically-poled reverse-proton-exchange lithium niobate waveguides with integrated mode demultiplexer at a wavelength of 1.5-um and a clock of 10 GHz. Using superconducting single photon detectors, we observed a coincidence to accidental count ratio (CAR) as high as 4000. The developed photon-pair source may find broad application in quantum information systems as well as quantum entanglement experiments.
[ { "version": "v1", "created": "Sat, 26 May 2007 05:16:32 GMT" } ]
2009-11-13T00:00:00
[ [ "Zhang", "Qiang", "" ], [ "Xie", "Xiuping", "" ], [ "Takesue", "Hiroki", "" ], [ "Nam", "Sae Woo", "" ], [ "Langrock", "Carsten", "" ], [ "Fejer", "Martin", "" ], [ "Yamamoto", "Yoshihisa", "" ] ]
0705.3876
Ruida Chen
Ruida Chen
New exact solution of Dirac-Coulomb equation with exact boundary condition
12 pages,no figures
null
10.1007/s10773-007-9514-z
null
quant-ph
null
It usually writes the boundary condition of the wave equation in the Coulomb field as a rough form without considering the size of the atomic nucleus. The rough expression brings on that the solutions of the Klein-Gordon equation and the Dirac equation with the Coulomb potential are divergent at the origin of the coordinates, also the virtual energies, when the nuclear charges number Z > 137, meaning the original solutions do not satisfy the conditions for determining solution. Any divergences of the wave functions also imply that the probability density of the meson or the electron would rapidly increase when they are closing to the atomic nucleus. What it predicts is not a truth that the atom in ground state would rapidly collapse to the neutron-like. We consider that the atomic nucleus has definite radius and write the exact boundary condition for the hydrogen and hydrogen-like atom, then newly solve the radial Dirac-Coulomb equation and obtain a new exact solution without any mathematical and physical difficulties. Unexpectedly, the K value constructed by Dirac is naturally written in the barrier width or the equivalent radius of the atomic nucleus in solving the Dirac equation with the exact boundary condition, and it is independent of the quantum energy. Without any divergent wave function and the virtual energies, we obtain a new formula of the energy levels that is different from the Dirac formula of the energy levels in the Coulomb field.
[ { "version": "v1", "created": "Sat, 26 May 2007 05:18:13 GMT" }, { "version": "v2", "created": "Mon, 28 May 2007 23:43:40 GMT" }, { "version": "v3", "created": "Fri, 29 Jun 2007 02:47:41 GMT" } ]
2009-11-13T00:00:00
[ [ "Chen", "Ruida", "" ] ]
0705.3877
Dominic van der Zypen
Maria-Luisa Colasante, Dominic van der Zypen
On the closure of the diagonal of a $T_1$-space
8 pages
null
null
null
math.GN math.LO
null
Let X be a topological space. The closure of \Delta = {(x, x) : x \in X} in X \times X is a symmetric relation on X. We characterise those equivalence relations on an infinite set that arise as the closure of the diagonal with respect to a T_1-topology.
[ { "version": "v1", "created": "Sat, 26 May 2007 06:25:00 GMT" } ]
2007-05-29T00:00:00
[ [ "Colasante", "Maria-Luisa", "" ], [ "van der Zypen", "Dominic", "" ] ]
0705.3878
Dominic van der Zypen
Michel Krebs, Dominic van der Zypen
Distributive lattice orderings and Priestley duality
9 pages
null
null
null
math.LO
null
The ordering relation of a bounded distributive lattice L is a (distributive) (0, 1)-sublattice of L \times L. This construction gives rise to a functor \Phi from the category of bounded distributive lattices to itself. We examine the interaction of \Phi with Priestley duality and characterise those bounded distributive lattices L such that there is a bounded distributive lattice K such that \Phi(K) is (isomorphic to) L.
[ { "version": "v1", "created": "Sat, 26 May 2007 06:41:14 GMT" } ]
2007-05-29T00:00:00
[ [ "Krebs", "Michel", "" ], [ "van der Zypen", "Dominic", "" ] ]
0705.3879
U. Zuelicke
S. Johnson (1), U. Zuelicke (2,3), A. Markwitz (1,3) ((1) GNS Science, (2) Massey U, (3) MacDiarmid Institute)
Universal characteristics of resonant-tunneling field emission from nanostructured surfaces
5 pages, 4 figures, RevTex, to appear in J. Appl. Phys
J. Appl. Phys. 101, 123712 (2007)
10.1063/1.2749284
null
cond-mat.mes-hall cond-mat.mtrl-sci
null
We have performed theoretical and experimental studies of field emission from nanostructured semiconductor cathodes. Resonant tunneling through electric-field-induced interface bound states is found to strongly affect the field-emission characteristics. Our analytical theory predicts power-law and Lorentzian-shaped current-voltage curves for resonant-tunneling field emission from three-dimensional substrates and two-dimensional accumulation layers, respectively. These predicted line shapes are observed in field emission characteristics from self-assembled silicon nanostructures. A simple model describes formation of an accumulation layer and of the resonant level in these systems.
[ { "version": "v1", "created": "Sat, 26 May 2007 07:04:26 GMT" } ]
2007-06-27T00:00:00
[ [ "Johnson", "S.", "" ], [ "Zuelicke", "U.", "" ], [ "Markwitz", "A.", "" ] ]
0705.3880
Dong Xu
Dong Xu, Nan Zhao, and Jia-Lin Zhu
Fine-structure splitting of exciton states in quantum dot molecules: symmetry and tunnel-coupling effects
8 pages, 8 figures
J. Phys.: Condens. Matter 20, 045204 (2008)
10.1088/0953-8984/20/04/045204
null
cond-mat.mes-hall
null
Exciton levels and fine-structure splitting in laterally-coupled quantum dot molecules are studied. The electron and hole tunneling energies as well as the direct Coulomb interaction are essential for the exciton levels. It is found that fine-structure splitting of the two-lowest exciton levels is contributed from the intra- and inter-dot exchange interactions, both of which are largely influenced by the symmetry and tunnel-coupling between the two dots. As the inter-dot separation is reduced, fine-structure splitting of the exciton ground state is largely increased while those of the excited states are decreased. Moreover, the dependence of the fine-structure splitting in quantum dot molecules on the Coulomb correlation is clearly clarified.
[ { "version": "v1", "created": "Sat, 26 May 2007 07:11:20 GMT" }, { "version": "v2", "created": "Thu, 21 Jun 2007 15:08:00 GMT" }, { "version": "v3", "created": "Mon, 25 Jun 2007 04:15:59 GMT" } ]
2015-05-13T00:00:00
[ [ "Xu", "Dong", "" ], [ "Zhao", "Nan", "" ], [ "Zhu", "Jia-Lin", "" ] ]
0705.3881
Chandrasekher Mukku Prof.
Bindu A. Bambah, Swadesh M. Mahajan and Chandrasekher Mukku
Topological structures in Yang Mills Magneto-Fluids
4 pages, 4 figures
null
null
null
hep-th hep-ph physics.flu-dyn
null
Knotted configurations supported by a Yang Mills fluid-field system are suggested as a model for glueballs.
[ { "version": "v1", "created": "Sat, 26 May 2007 07:21:15 GMT" } ]
2007-05-29T00:00:00
[ [ "Bambah", "Bindu A.", "" ], [ "Mahajan", "Swadesh M.", "" ], [ "Mukku", "Chandrasekher", "" ] ]
0705.3882
Suresh Tiwari dr
S. C. Tiwari
Viscous Spacetime Fluid and Higher Curvature Gravity
4 pages, no figures, submitted for publication
null
null
null
gr-qc
null
The Einstein field equation as an equation of state of a thermodynamical system of spacetime is reconsidered in the present Letter. We argue that a consistent interpretation leads us to identify scalar curvature and cosmological constant terms representing the bulk viscosity of the spacetime fluid. Since Einstein equation itself corresponds to a near-equilibrium state in this interpretation invoking $f(R)$ gravity for nonequilibrium thermodynamics is not required. A logically consistent generalization to include the effect of so called 'tidal forces' due to the Riemann curvature is presented. A new equation of state for higher curvature gravity is derived and its physical interpretation is discussed.
[ { "version": "v1", "created": "Sat, 26 May 2007 08:12:16 GMT" } ]
2007-05-29T00:00:00
[ [ "Tiwari", "S. C.", "" ] ]
0705.3883
Suresh Tiwari dr
S. C. Tiwari
Comment on "Cyclotron resonance study of the electron and hole velocity in graphene monolayers"
2 pages no figures
null
null
null
physics.gen-ph
null
In this comment it is pointed out that the electron velocity of the same order as observed in graphene had been measured in GaAs submicron devices long ago. Particle- antiparticle asymmetry related with electron and hole effective masses in graphene seems puzzling as hole in a condensed matter system cannot be treated as anti-electron. It is argued that there should be a universal electrodynamics for QHE and superconductivity. In this context attention is drawn to the new approach based on massless electron and the interpretation that magnetic field represents angular momentum of the photon fluid. Measurement of electron velocity in graphene and GaAs in parallel is suggested for testing the massless electrodynamics.
[ { "version": "v1", "created": "Sat, 26 May 2007 08:19:56 GMT" } ]
2007-05-29T00:00:00
[ [ "Tiwari", "S. C.", "" ] ]
0705.3884
Hiroki Nakamura
Hiroki Nakamura, Tadaaki Nasu, Makoto Sakuda, Omar Benhar
Inclusive electron spectrum in the region of pion production in electron-nucleus scattering and the effect of the quasi-elastic interaction
4 pages, 3 figures. v2: major change made, to fit in the jouranl format. v3: minor change made
Phys.Rev.C76:065208,2007; AIP Conf.Proc.967:187-191,2007
10.1103/PhysRevC.76.065208 10.1063/1.2834475
null
hep-ph
null
We have carried out a calculation of the inclusive electron scattering cross section off oxygen in the kinematical region corresponding to beam energies between 700 and 1200 MeV, where quasielastic scattering and single pion production are the dominant reaction mechanisms. The formalism developed and successfully applied to describe quasielastic scattering has been extended to include both delta production and non-resonant pion production. The results are in fairly good agreement with experimental data over the whole range of energy transfer, including the dip region between the quasielastic peak and the first resonance.
[ { "version": "v1", "created": "Mon, 28 May 2007 10:09:06 GMT" }, { "version": "v2", "created": "Fri, 7 Sep 2007 09:06:02 GMT" }, { "version": "v3", "created": "Thu, 8 Nov 2007 05:32:35 GMT" } ]
2009-04-22T00:00:00
[ [ "Nakamura", "Hiroki", "" ], [ "Nasu", "Tadaaki", "" ], [ "Sakuda", "Makoto", "" ], [ "Benhar", "Omar", "" ] ]
0705.3885
Yao Chen
Y. Chen, Y. Q. Hu, S. J. Sun
Catastrophic eruption of magnetic flux rope in the corona and solar wind with and without magnetic reconnection
7 pages, 4 figures, ApJ, in press (vol. 666, Sept. 2007)
Astrophys.J.665:1421-1427,2007
10.1086/519551
null
astro-ph
null
It is generally believed that the magnetic free energy accumulated in the corona serves as a main energy source for solar explosions such as coronal mass ejections (CMEs). In the framework of the flux rope catastrophe model for CMEs, the energy may be abruptly released either by an ideal magnetohydrodynamic (MHD) catastrophe, which belongs to a global magnetic topological instability of the system, or by a fast magnetic reconnection across preexisting or rapidly-developing electric current sheets. Both ways of magnetic energy release are thought to be important to CME dynamics. To disentangle their contributions, we construct a flux rope catastrophe model in the corona and solar wind and compare different cases in which we either prohibit or allow magnetic reconnection to take place across rapidly-growing current sheets during the eruption. It is demonstrated that CMEs, even fast ones, can be produced taking the ideal MHD catastrophe as the only process of magnetic energy release. Nevertheless, the eruptive speed can be significantly enhanced after magnetic reconnection sets in. In addition, a smooth transition from slow to fast eruptions is observed when increasing the strength of the background magnetic field, simply because in a stronger field there is more free magnetic energy at the catastrophic point available to be released during an eruption. This suggests that fast and slow CMEs may have an identical driving mechanism.
[ { "version": "v1", "created": "Sat, 26 May 2007 12:44:16 GMT" } ]
2009-06-23T00:00:00
[ [ "Chen", "Y.", "" ], [ "Hu", "Y. Q.", "" ], [ "Sun", "S. J.", "" ] ]
0705.3886
Yao Chen
Y. Chen, Y. Q. Hu, L. D. Xia
Two Energy Release Processes for CMEs: MHD Catastrophe and Magnetic Reconnection
7 pages, 4 figures, Adv. Spa. Res., in press,
Adv.Space Res.40:1780-1786,2007
10.1016/j.asr.2007.02.011
null
astro-ph
null
It remains an open question how magnetic energy is rapidly released in the solar corona so as to create solar explosions such as solar flares and coronal mass ejections (CMEs). Recent studies have confirmed that a system consisting of a flux rope embedded in a background field exhibits a catastrophic behavior, and the energy threshold at the catastrophic point may exceed the associated open field energy. The accumulated free energy in the corona is abruptly released when the catastrophe takes place, and it probably serves as the main means of energy release for CMEs at least in the initial phase. Such a release proceeds via an ideal MHD process in contrast with nonideal ones such as magnetic reconnection. The catastrophe results in a sudden formation of electric current sheets, which naturally provide proper sites for fast magnetic reconnection. The reconnection may be identified with a solar flare associated with the CME on one hand, and produces a further acceleration of the CME on the other. On this basis, several preliminary suggestions are made for future observational investigations, especially with the proposed KuaFu satellites, on the roles of the MHD catastrophe and magnetic reconnection in the magnetic energy release associated with CMEs and flares.
[ { "version": "v1", "created": "Sat, 26 May 2007 14:02:01 GMT" } ]
2009-06-23T00:00:00
[ [ "Chen", "Y.", "" ], [ "Hu", "Y. Q.", "" ], [ "Xia", "L. D.", "" ] ]
0705.3887
Massimiliano Grazzini
G. Bozzi, S. Catani, D. de Florian, M. Grazzini
Higgs boson production at the LHC: transverse-momentum resummation and rapidity dependence
References added
Nucl.Phys.B791:1-19,2008
10.1016/j.nuclphysb.2007.09.034
null
hep-ph
null
We consider Higgs boson production by gluon fusion in hadron collisions. We study the doubly-differential transverse-momentum (q_T) and rapidity (y) distribution of the Higgs boson in perturbative QCD. In the region of small q_T (q_T << M_H, M_H being the mass of the Higgs boson), we include the effect of logarithmically-enhanced contributions due to multiparton radiation to all perturbative orders. We use the impact parameter and double Mellin moments to implement and factorize the multiparton kinematics constraint of transverse- and longitudinal-momentum conservation. The logarithmic terms are then systematically resummed in exponential form. At small q_T, we perform the all-order resummation of large logarithms up to next-to-next-to-leading logarithmic accuracy, while at large q_T (q_T ~ M_H), we apply a matching procedure that recovers the fixed-order perturbation theory up to next-to-leading order. We present quantitative results for the differential cross section in q_T and y at the LHC, and we comment on the comparison with the q_T cross section integrated over y.
[ { "version": "v1", "created": "Sat, 26 May 2007 09:49:07 GMT" }, { "version": "v2", "created": "Mon, 11 Feb 2008 11:56:13 GMT" } ]
2008-11-26T00:00:00
[ [ "Bozzi", "G.", "" ], [ "Catani", "S.", "" ], [ "de Florian", "D.", "" ], [ "Grazzini", "M.", "" ] ]
0705.3888
Antoine Meyer
Ahmed Bouajjani (LIAFA), Antoine Meyer (LIAFA)
Symbolic Reachability Analysis of Higher-Order Context-Free Processes
null
FSTTCS 2004: Foundations of Software Technology and Theoretical Computer Science (24/11/2004) 135-147
10.1007/b104325
null
cs.LO
null
We consider the problem of symbolic reachability analysis of higher-order context-free processes. These models are generalizations of the context-free processes (also called BPA processes) where each process manipulates a data structure which can be seen as a nested stack of stacks. Our main result is that, for any higher-order context-free process, the set of all predecessors of a given regular set of configurations is regular and effectively constructible. This result generalizes the analogous result which is known for level 1 context-free processes. We show that this result holds also in the case of backward reachability analysis under a regular constraint on configurations. As a corollary, we obtain a symbolic model checking algorithm for the temporal logic E(U,X) with regular atomic predicates, i.e., the fragment of CTL restricted to the EU and EX modalities.
[ { "version": "v1", "created": "Mon, 28 May 2007 16:31:04 GMT" } ]
2007-05-29T00:00:00
[ [ "Bouajjani", "Ahmed", "", "LIAFA" ], [ "Meyer", "Antoine", "", "LIAFA" ] ]
0705.3889
Matthew Shetrone
Matthew Shetrone, Mark E. Cornell, James R. Fowler, Niall Gaffney, Benjamin Laws, Jeff Mader, Cloud Mason, Stephen Odewahn, Brian Roman, Sergey Rostopchin, Donald P. Schneider, James Umbarger, and Amy Westfall
Ten Year Review of Queue Scheduling of the Hobby-Eberly Telescope
latex file of 27 pages including 5 figures. Accepted to PASP
null
10.1086/519291
null
astro-ph
null
This paper presents a summary of the first 10 years of operating the Hobby-Eberly Telescope (HET) in queue mode. The scheduling can be quite complex but has worked effectively for obtaining the most science possible with this uniquely designed telescope. The queue must handle dozens of separate scientific programs, the involvement of a number of institutions with individual Telescope Allocation Committees as well as engineering and instrument commissioning. We have continuously revised our queue operations as we have learned from experience. The flexibility of the queue and the simultaneous availability of three instruments, along with a staff trained for all aspects of telescope and instrumentation operation, have allowed optimum use to be made of variable weather conditions and have proven to be especially effective at accommodating targets of opportunity and engineering tasks. In this paper we review the methodology of the HET queue along with its strengths and weaknesses.
[ { "version": "v1", "created": "Sat, 26 May 2007 10:13:39 GMT" } ]
2019-08-19T00:00:00
[ [ "Shetrone", "Matthew", "" ], [ "Cornell", "Mark E.", "" ], [ "Fowler", "James R.", "" ], [ "Gaffney", "Niall", "" ], [ "Laws", "Benjamin", "" ], [ "Mader", "Jeff", "" ], [ "Mason", "Cloud", "" ], [ "Odewahn", "Stephen", "" ], [ "Roman", "Brian", "" ], [ "Rostopchin", "Sergey", "" ], [ "Schneider", "Donald P.", "" ], [ "Umbarger", "James", "" ], [ "Westfall", "Amy", "" ] ]
0705.3890
Akihiko Minami
Akira Onuki and Akihiko Minami
Phase transition in compressible Ising systems at fixed volume
13 figures
null
10.1103/PhysRevB.76.174427
null
cond-mat.mtrl-sci
null
Using a Ginzburg-Landau model, we study the phase transition behavior of compressible Ising systems at constant volume by varying the temperature $T$ and the applied magnetic field $h$. We show that two phases can coexist macroscopically in equilibrium within a closed region in the $T$-$h$ plane. It occurence is favored near tricriticality. We find a field-induced critical point, where the correlation length diverges, the difference of the coexisting two phases and the surface tension vanish, but the isothermal magnetic susceptibility does not diverge in the mean field theory. We also investigate phase ordering numerically.
[ { "version": "v1", "created": "Sat, 26 May 2007 10:54:53 GMT" } ]
2009-11-13T00:00:00
[ [ "Onuki", "Akira", "" ], [ "Minami", "Akihiko", "" ] ]
0705.3891
Sergio Caracciolo
Sergio Caracciolo (Milan U. & INFN, Milan), Claudia De Grandi (Boston U.), Andrea Sportiello (Milan U. & INFN, Milan)
Renormalization flow for unrooted forests on a triangular lattice
26 pages, 4 figures
Nucl.Phys.B787:260-282,2007
10.1016/j.nuclphysb.2007.06.012
null
cond-mat.stat-mech hep-lat
null
We compute in small temperature expansion the two-loop renormalization constants and the three-loop coefficient of the beta-function, that is the first non-universal term, for the sigma-model with O(N) invariance on the triangular lattice at N=-1. The partition function of the corresponding Grassmann theory is, for negative temperature, the generating function of unrooted forests on such a lattice, where the temperature acts as a chemical potential for the number of trees in the forest. To evaluate Feynman diagrams we extend the coordinate space method to the triangular lattice.
[ { "version": "v1", "created": "Sat, 26 May 2007 11:41:45 GMT" }, { "version": "v2", "created": "Thu, 14 Jun 2007 17:44:16 GMT" } ]
2008-11-26T00:00:00
[ [ "Caracciolo", "Sergio", "", "Milan U. & INFN, Milan" ], [ "De Grandi", "Claudia", "", "Boston\n U." ], [ "Sportiello", "Andrea", "", "Milan U. & INFN, Milan" ] ]
0705.3892
Sergei Alexandrov
Sergei Alexandrov
Spin foam model from canonical quantization
26 pages; presentation improved, important changes concerning the closure constraint and the vertex amplitude; minor correction
Phys.Rev.D77:024009,2008
10.1103/PhysRevD.77.024009
PTA/07-24
gr-qc
null
We suggest a modification of the Barrett-Crane spin foam model of 4-dimensional Lorentzian general relativity motivated by the canonical quantization. The starting point is Lorentz covariant loop quantum gravity. Its kinematical Hilbert space is found as a space of the so-called projected spin networks. These spin networks are identified with the boundary states of a spin foam model and provide a generalization of the unique Barrette-Crane intertwiner. We propose a way to modify the Barrett-Crane quantization procedure to arrive at this generalization: the B field (bi-vectors) should be promoted not to generators of the gauge algebra, but to their certain projection. The modification is also justified by the canonical analysis of Plebanski formulation. Finally, we compare our construction with other proposals to modify the Barret-Crane model.
[ { "version": "v1", "created": "Sat, 26 May 2007 12:21:12 GMT" }, { "version": "v2", "created": "Mon, 5 Nov 2007 14:54:49 GMT" }, { "version": "v3", "created": "Fri, 22 Feb 2008 20:42:47 GMT" } ]
2008-11-26T00:00:00
[ [ "Alexandrov", "Sergei", "" ] ]
0705.3893
Daniel Hook
Carl M. Bender, Darryl D. Holm, Daniel W. Hook
Complexified Dynamical Systems
13 pages, 12 figures, to appear in Fast Track Communications, Journal of Physics A: Mathematical and Theoretical
J.Phys.A40:F793-F804,2007
10.1088/1751-8113/40/32/F02
LA-UR-07-3496
hep-th nlin.SI
null
Many dynamical systems, such as the Lotka-Volterra predator-prey model and the Euler equations for the free rotation of a rigid body, are PT symmetric. The standard and well-known real solutions to such dynamical systems constitute an infinitessimal subclass of the full set of complex solutions. This paper examines a subset of the complex solutions that contains the real solutions, namely, those having PT symmetry. The condition of PT symmetry selects out complex solutions that are periodic.
[ { "version": "v1", "created": "Sat, 26 May 2007 12:47:12 GMT" }, { "version": "v2", "created": "Tue, 29 May 2007 07:23:03 GMT" }, { "version": "v3", "created": "Wed, 4 Jul 2007 23:06:30 GMT" } ]
2008-11-26T00:00:00
[ [ "Bender", "Carl M.", "" ], [ "Holm", "Darryl D.", "" ], [ "Hook", "Daniel W.", "" ] ]
0705.3894
Sima Ghassemi Dr.
M. Sadegh Movahed and Sima Ghassemi
Is Thick Brane Model Consistent with the Recent Observations?
15 pages and 15 figures, V2: Added references and minor corrections, main results and conclusions unchanged
Phys.Rev.D76:084037,2007
10.1103/PhysRevD.76.084037
IPM/P-2007/036
astro-ph
null
There exist many observational evidences implying the expansion of our universe is undergoing a late-time acceleration, the mechanism of this acceleration is yet unknown. In the so-called thick brane model this phenomena is attributed to the thickness of the brane along the extra dimension. In this study we mainly rely to the consistency of this model with most recent observational data related to the background evolution. The new Supernova Type Ia (SNIa) Gold sample and Supernova Legacy Survey (SNLS) data, the position of the acoustic peak at the last scattering surface from the WMAP observations and the baryon acoustic oscillation peak found in the Sloan Digital Sky Survey (SDSS) are used to constrain the free parameter of the thick codimension 1 brane model. To infer its consistency with age of our universe, we compare the age of old cosmological objects with what computed using the best fit values for the model parameters. When the universe is matter dominated, $w=0$, at 68% level of confidence, the combination of Gold sample SNIa, CMB shift parameter and SDSS databases provides $\Omega_m=0.31_{-0.02}^{+0.02}$, $\Omega_{\cal{C}}=0.05_{-0.01}^{+0.01}$, $w_r=-1.40_{-0.20}^{+0.20}$, hence a spatially open universe with $\Omega_k=0.21_{-0.08}^{+0.08}$. The same combination with SNLS supernova observation gives $\Omega_m=0.28_{-0.02}^{+0.03}$, $\Omega_{\cal{C}}=0.037_{-0.004}^{+0.003}$, $w_r=-2.05_{-0.15}^{+0.15}$ consequently provides a spatially open universe $\Omega_k=0.11_{-0.07}^{+0.10}$. These results obviously seem to be in contradiction with the most recent WMAP results indicating a flat universe.
[ { "version": "v1", "created": "Sat, 26 May 2007 12:46:29 GMT" }, { "version": "v2", "created": "Sat, 3 Nov 2007 10:56:15 GMT" } ]
2008-12-18T00:00:00
[ [ "Movahed", "M. Sadegh", "" ], [ "Ghassemi", "Sima", "" ] ]
0705.3895
Apoorva Patel
Apoorva D. Patel
Towards Understanding the Origin of Genetic Languages
(v1) 33 pages, contributed chapter to "Quantum Aspects of Life", edited by D. Abbott, P. Davies and A. Pati, (v2) published version with some editing
null
10.1142/9781848162556_0010
null
q-bio.GN cs.IT math.IT physics.bio-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Molecular biology is a nanotechnology that works--it has worked for billions of years and in an amazing variety of circumstances. At its core is a system for acquiring, processing and communicating information that is universal, from viruses and bacteria to human beings. Advances in genetics and experience in designing computers have taken us to a stage where we can understand the optimisation principles at the root of this system, from the availability of basic building blocks to the execution of tasks. The languages of DNA and proteins are argued to be the optimal solutions to the information processing tasks they carry out. The analysis also suggests simpler predecessors to these languages, and provides fascinating clues about their origin. Obviously, a comprehensive unraveling of the puzzle of life would have a lot to say about what we may design or convert ourselves into.
[ { "version": "v1", "created": "Sat, 26 May 2007 13:01:20 GMT" }, { "version": "v2", "created": "Tue, 28 Oct 2008 11:37:41 GMT" } ]
2016-12-21T00:00:00
[ [ "Patel", "Apoorva D.", "" ] ]
0705.3896
Roberto Miwa
R. H. Miwa, T. B. Martins, and A. Fazzio
Hydrogen adsorption on boron doped graphene: an {\it ab initio} study
7 pages, 4 figures
null
10.1088/0957-4484/19/15/155708
null
cond-mat.mtrl-sci
null
The electronic and structural properties of (i) boron doped graphene sheets, and (ii) the chemisorption processes of hydrogen adatoms on the boron doped graphene sheets have been examined by {\it ab initio} total energy calculations.
[ { "version": "v1", "created": "Sat, 26 May 2007 15:14:30 GMT" } ]
2015-05-13T00:00:00
[ [ "Miwa", "R. H.", "" ], [ "Martins", "T. B.", "" ], [ "Fazzio", "A.", "" ] ]
0705.3897
Dirk Kreimer
Dirk Kreimer
A remark on quantum gravity
9p, several eps figures
Annals Phys.323:49-60,2008
10.1016/j.aop.2007.06.005
IHES/P/07/20
hep-th gr-qc math-ph math.MP
null
We discuss the structure of Dyson--Schwinger equations in quantum gravity and conclude in particular that all relevant skeletons are of first order in the loop number. There is an accompanying sub Hopf algebra on gravity amplitudes equivalent to identities between n-graviton scattering amplitudes which generalize the Slavnov Taylor identities. These identities map the infinite number of charges and finite numbers of skeletons in gravity to an infinite number of skeletons and a finite number of charges needing renormalization. Our analysis suggests that gravity, regarded as a probability conserving but perturbatively non-renormalizable theory, is renormalizable after all, thanks to the structure of its Dyson--Schwinger equations.
[ { "version": "v1", "created": "Sat, 26 May 2007 15:28:58 GMT" } ]
2009-04-17T00:00:00
[ [ "Kreimer", "Dirk", "" ] ]