June 2006 arXiv papers — page 42
Showing 4,101–4,200 of 4,372 papers
D. Ebert, K. G. Klimenko, V. Ch. Zhukovsky, A. M. Fedotov
The general features of quark and pion condensation in dense quark matter with flavor asymmetry have been considered at finite temperature in the presence of a chromomagnetic background field modelling the gluon condensate. In particular, pion condensation in the case of a constant abelian chromomagnetic field and zero temperature has been studied both analy
Dileptons from vector mesons with dropping masses in a nonequilibrium quantum field theoretical framework
hep-phC. Greiner, B. Schenke
The influence of time dependent medium modifications of low mass vector mesons on dilepton production is investigated using nonequilibrium quantum field theory. By working in the two-time representation memory effects are fully taken into account. For different scenarios the resulting dilepton yields are compared to quasi-equilibrium calculations and remarka
D. U. Matrasulov, F. C. Khanna, Kh. T. Butanov, Kh. Yu. Rakhimov
Finite-temperature spectra of heavy quarkonia are calculated by combining potential model and thermofield dynamics formalisms. The mass spectra of the heavy quarkonia with various quark contents are calculated. It is found that binding mass of the quarkonium decreases as temperature increases.
Vladimir Dzhunushaliev
It is shown that the quantum SU(3) gauge theory can be approximately reduced to U(1) gauge theory with broken gauge symmetry and interacting with scalar fields. The scalar fields are some approximation for 2 and 4-points Green's functions of $A^{1, ..., 7}_μ$ gauge potential components. Remaining gauge potential component $A^8_μ$ is the potential for U(1
Vladimir Dzhunushaliev
On the basis of the non-perturbative Heisenberg's quantization scheme and using some simplifications and assumptions the reduction from the gluon-quark Lagrangian to a scalar-fermion Lagrangian is made. The corresponding field equations have a regular spherically symmetric solution which can be interpret as a simplified model of nucleon. Some properties
Harvey B. Meyer, Hubert Simma, Rainer Sommer, Michele Della Morte
We study autocorrelation times of physical observables in lattice QCD as a function of the molecular dynamics trajectory length in the hybrid Monte-Carlo algorithm. In an interval of trajectory lengths where energy and reversibility violations can be kept under control, we find a variation of the integrated autocorrelation times by a factor of about two in t
A. J. Bevan
Rare hadronic B-meson decays allow us to study CP violation. The class of B decays final states containing two vector mesons provides a rich set of angular correlation observables to study. This article reviews some of the recent experimental results from the BaBar and Belle collaborations.
Helmut Vogel
Bound upsilon states and their decays provide a unique laboratory for testing QCD, LQCD, and quarkonium potential models. I review recent results, some of which are significant improvements in precision over previous measurements and others are first-time observations. While most of the results presented are from CLEO III there are also notable contributions
O. Igonkina
Today the B-factories BaBar and Belle have accumulated largest samples of tau-tau events and are competing to be called tau-factories. Among the problems to be tested and measurements to be done by BaBar and Belle are check of CP and CPT invariance in tau decays, measurement of strange and non-strange spectral functions, extraction of mass of strange quark a
2 collaboration
A search for direct CP-violation in K+- --> pi+-pi0pi0 decays based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes A_g=(g^+ - g^-)/(g^+ + g^-) is measured to be A_g=(1.8 +- 2.6).10^{-4}. The design of the experiment and the method of analysis provide good control of instrume
Measurement of Through-Going Particle Momentum By Means Of Multiple Scattering With The ICARUS T600 TPC
hep-exICARUS Collaboration, A. Ankowski
The ICARUS collaboration has demonstrated, following the operation of a 600 ton (T600) detector at shallow depth, that the technique based on liquid Argon TPCs is now mature. The study of rare events, not contemplated in the Standard Model, can greatly benefit from the use of this kind of detectors. In particular, a deeper understanding of atmospheric neutri
German Izquierdo, Diego Pavon
This Letter considers the generalized second law of gravitational thermodynamics in two scenarios featuring a phantom dominated expansion plus a black hole. The law is violated in both scenarios.
Kamal K. Nandi, Yuan-Zhong Zhang
Using the ansatz of Matos and Núñez, the present article proposes an algorithm for generating several classes, not all independent, of asymptotically flat rotating wormhole solutions in the Brans-Dicke Theory. The algorithm allows us to associate a real number}$n$ \textit{with} \textit{each static and generated rotating solution. We shall also demonstrate ho
J. David Brown, Lisa L. Lowe
A new technique is presented for modifying the Einstein evolution equations off the constraint hypersurface. With this approach the evolution equations for the constraints can be specified freely. The equations of motion for the gravitational field variables are modified by the addition of terms that are linear and nonlocal in the constraints. These terms ar
M. Abellanas, A. Bajuelos, G. Hernández, F. Hurtado
A point p is 1-well illuminated by a set F of n point lights if p lies in the interior of the convex hull of F. This concept corresponds to triangle-guarding or well-covering. In this paper we consider the illumination range of the light sources as a parameter to be optimized. First, we solve the problem of minimizing the light sources' illumination rang
On the communication between cells of a cellular automaton on the penta- and heptagrids of the hyperbolic plane
cs.CGMaurice Margenstern
This contribution belongs to a combinatorial approach to hyperbolic geometry and it is aimed at possible applications to computer simulations. It is based on the splitting method which was introduced by the author and which is reminded in the second section of the paper. Then we sketchily remind the application to the classical case of the pentagrid, i.e. th
V. V. Kryssanov, V. A. Abramov, Y. Fukuda, K. Konishi
The research results described are concerned with: - developing a domain modeling method and tools to provide the design and implementation of decision-making support systems for computer integrated manufacturing; - building a decision-making support system based on know-how and its software environment. The research is funded by NEDO, Japan.
Quantitative calculations of the excitonic energy spectra of semiconducting single-walled carbon nanotubes within a $π$-electron model
cond-mat.mtrl-sciZhendong Wang, Hongbo Zhao, Sumit Mazumdar
Using Coulomb correlation parameters appropriate for $π$-conjugated polymers (PCPs), and a nearest neighbor hopping integral that is arrived at by fitting the energy spectra of three zigzag semiconducting single-walled carbon nanotubes (S-SWCNTs), we are able to determine quantitatively the exciton energies and exciton binding energies of 29 S-SWCNTs within
Ole Peters, J. David Neelin
Critical phenomena near continuous phase transitions are typically observed on the scale of wavelengths of visible light[1]. Here we report similar phenomena for atmospheric precipitation on scales of tens of kilometers. Our observations have important implications not only for meteorology but also for the interpretation of self-organized criticality (SOC) i
Critical behavior and synchronization of discrete stochastic phase coupled oscillators
cond-mat.stat-mechKevin Wood, C. Van den Broeck, R. Kawai, Katja Lindenberg
Synchronization of stochastic phase-coupled oscillators is known to occur but difficult to characterize because sufficiently complete analytic work is not yet within our reach, and thorough numerical description usually defies all resources. We present a discrete model that is sufficiently simple to be characterized in meaningful detail. In the mean field li
K. Vakili, T. Gokmen, O. Gunawan, Y. P. Shkolnikov
We report measurements of the quantum Hall state energy gap at avoided crossings between Landau levels originating from different conduction band valleys in AlAs quantum wells. These gaps exhibit an approximately linear dependence on magnetic field over a wide range of fields and filling factors. More remarkably, we observe an unexpected dependence of the ga
K. Vakili, Y. P. Shkolnikov, E. Tutuc, E. P. De Poortere
Employing state-of-the-art molecular beam epitaxy techniques to grow thin, modulation-doped AlAs quantum wells, we have achieved a low temperature mobility of 5.5 m$^2$/Vs with out-of-plane occupation, an order of magnitude improvement over previous studies. However, due to the narrow well width, mobilities are still limited by scattering due to interface ro
J. Marciak-Kozlowska, M. kozlowski
In this paper we investigate the heat transport induced by continuous laser beams up to an intensity of about 1029 Watt/cm2. We maintain that up to this intensity nonlinear effects are negligible and that the application of the linear hyperbolic heat transport equation is fully justifiable. We show that the Fourier diffusion equation gives the speed of diffu
G. Tellez, E. Trizac
The mathematical theory of integrable Painleve/Toda type systems sheds new light on the behavior of solutions to the Poisson-Boltzmann equation for the potential due to a long rod-like macroion. We investigate here the case of symmetric electrolytes together with that of 1:2 and 2:1 salts. Short and large scale features are analyzed, with a particular emphas
Effects of spin-phonon interaction on the properties of in high-T$_C$ superconductors
cond-mat.mtrl-sciT. Jarlborg
The mechanism of spin-phonon coupling in high-T$_C$ copper oxides is explored from band calculations on La$_{(2-x)}$Sr$_x$CuO$_4$ and HgBa$_2$CuO$_4$ systems. The LMTO band calculations, based on the local density approximation, are made for cells containing frozen phonon displacements and/or spin waves within the CuO plane. The virtual crystal approximation
Temperature and magnetic field dependences of the elastic constants of Ni-Mn-Al magnetic Heusler alloys
cond-mat.mtrl-sciXavier Moya, Lluis Manosa, Antoni Planes, Thorsten Krenke
We report on measurements of the adiabatic second order elastic constants of the off-stoichiometric Ni$_{54}$Mn$_{23}$Al$_{23}$ single crystalline Heusler alloy. The variation in the temperature dependence of the elastic constants has been investigated across the magnetic transition and over a broad temperature range. Anomalies in the temperature behaviour o
G. Quirion, W. Wu, J. Rideout, B. Mroz
We report a detailed investigation of the elastic properties of Rb4LiH3(SO4)4 measured as a function of temperature and pressure. Rb4LiH3(SO4)4 is known to show a 4 - 2 ferroelastic phase transition at Tc = 134 K. In order to clarify the nature of the order parameter associated with that structural transition, we compare our finding to two distinct phenomelo
Importance of the Electron-Phonon Interaction with the Forward Scattering Peak for Superconducting Pairing in Cuprates
cond-mat.supr-conMiodrag L. Kulic
Basic experimental facts related to ARPES, tunnelling, optics ad neutron scattering measurements are discussed. They give evidence for the relevance of the electron-phonon interaction (EPI) in pairing mechanism of HTSC cuprates. A controllable theory for strong correlations and their effects on EPI is discussed which is based on the 1/N expansion method in t
Carlos P. Herrero, Rafael Ramirez, Eduardo R. Hernandez
Isolated hydrogen, deuterium, and muonium in diamond have been studied by path-integral molecular dynamics simulations in the canonical ensemble. Finite-temperature properties of these point defects were analyzed in the range from 100 to 800 K. Interatomic interactions were modeled by a tight-binding potential fitted to density-functional calculations. The m
Electronic structure of Diluted Magnetic Semiconductors $Ga_{1-x}Mn_{x}N$ and $Ga_{1-x}Cr_{x}N$
cond-mat.mtrl-sciNandan Tandon, G P Das, Anjali Kshirsagar
We have undertaken a study of diluted magnetic semiconductors $Ga_{1-x}Mn_{x}N$ and $Ga_{1-x}Cr_{x}N$ with $x=0.0625, 0.125$, using the all electron linearized augmented plane wave method (LAPW) for different configurations of Mn as well as Cr. We study four possible configurations of the impurity in the wurtzite GaN structure to predict energetically most f
D. J. J. Farnell, R. F. Bishop
A review of the coupled cluster method (CCM) applied to lattice quantum spin systems is presented here. The CCM formalism is explained and an application to the spin-half {\it XXZ} model on the square lattice is presented. Low orders of approximation are carried out analytically and a high-order CCM formulation is presented. Results for the SUB2 approximatio
Marcin Raczkowski, Raymond Fresard, Andrzej M. Oles
We establish the qualitative behavior of the incommensurability $ε$, optimal domain wall filling $ν$ and chemical potential $μ$ for increasing doping by a systematic slave-boson study of an array of vertical stripes separated by up to $d=11$ lattice constants. Our findings obtained in the Hubbard model with the next-nearest neighbor hopping $t'=-0.15t$ a
Mihail Vladkov, J. -L. Barrat
By applying local primitive path and Rouse modes analysis we study the chains conformations, local dynamics and viscosity of a model polymer melt in a polymer-wall interface. We establish that the presence of a repulsive wall leads to acceleration of the dynamics both for unentangled and weakly entangled melts and to a depletion in the entanglement density i
Exchange distortion and spin Jahn-Teller effect for triangular and tetrahedral spin clusters of spin-1/2
cond-mat.otherKiyosi Terao, Ikumi Honda
We study the effects of magneto-elastic coupling on the degenerate ground state of the antiferromagnetic Heisenberg model on regular triangle and tetrahedron clusters of spin-1/2. Both give very similar results. Static distortion lifts the degeneracy of the ground state through the distance dependence of the exchange coupling. On the contrary, quantum-mechan
E. V. Surovtsev, I. A. Fomin
Stability of homogeneous precession of spin due to parametric excitation of spin waves is considered as the explanation of the "catastrophic relaxation", that is observed in the superfluid 3He-B. It is shown, that at sufficiently low temperatures homogeneous precession of spin becomes unstable (Suhl instability). At zero temperature increments of gro
J. Trullas, V. Bitrian
Three different polarizable ion models for molten AgBr have been studied by molecular dynamics simulations. The three models are based on a rigid ion model (RIM) with a pair potential of the type proposed by Vashishta and Rahman for alpha-AgI, to which the induced dipole polarization of the ions is added. In the first (PIM1), the dipole moments are only indu
Michael Bortz
We study the Drude weight $D(T)$ at finite temperatures $T$ of an integrable bosonic model where the particles interact via nearest-neighbour coupling on a chain. At low temperatures, $D(T)$ is shown to be universal in the sense that this region is equivalently described by a Gaussian model. This low-temperature limit is also relevant for the integrable one-
G. Quirion, X. Han, M. L. Plumer, M. Poirier
By means of high-resolution ultrasonic velocity measurements, as a function of temperature and magnetic field, the nature of the different low temperatures magnetic phase transitions observed for the quasi-one-dimensional compound CsNiCl3 is established. Special attention has been devoted to the field-induced 120 degree phase transition above the multicritic
Synchronization transition of heterogeneously coupled oscillators on scale-free networks
cond-mat.stat-mechE. Oh, D. -S. Lee, B. Kahng, D. Kim
We investigate the synchronization transition of the modified Kuramoto model where the oscillators form a scale-free network with degree exponent $λ$. An oscillator of degree $k_i$ is coupled to its neighboring oscillators with asymmetric and degree-dependent coupling in the form of $\couplingcoeff k_i^{η-1}$. By invoking the mean-field approach, we determin
Tunable Resonant Raman Scattering from Singly Resonant Single Wall Carbon Nanotubes
cond-mat.mtrl-sciY. Yin, A. G. Walsh, A. N. Vamivakas, S. Cronin
We perform tunable resonant Raman scattering on 17 semiconducting and 7 metallic singly resonant single wall carbon nanotubes. The measured scattering cross-section as a function laser energy provides information about a tube's electronic structure, the lifetime of intermediate states involved in the scattering process and also energies of zone center op
J. Kronjäger, C. Becker, P. Navez, K. Bongs
We present the experimental observation of a magnetically tuned resonance phenomenon resulting from spin mixing dynamics of ultracold atomic gases. In particular we study the magnetic field dependence of spin conversion in F=2 87Rb spinor condensates in the crossover from interaction dominated to quadratic Zeeman dominated dynamics. We discuss the observed p
Anil C. Seth, Julianne J. Dalcanton, Paul W. Hodge, Victor P. Debattista
From observations of edge-on, late-type galaxies, we present morphological evidence that some nuclear star clusters have experienced in situ star formation. We find three nuclear clusters that, viewed from the edge-on perspective, have both a compact disk-like component and a spheroidal component. In each cluster, the disk components are closely aligned with
T. E. Jeltema, J. S. Mulchaey, L. M. Lubin, P. Rosati
We have undertaken a multiwavelength project to study the relatively unknown properties of groups and poor clusters of galaxies at intermediate redshifts. In this paper, we describe the XMM-Newton observations of six X-ray selected groups with 0.2<z<0.6. The X-ray properties of these systems are generally in good agreement with the properties of low-redshift
John S. Mulchaey, Lori M. Lubin, Chris Fassnacht, Piero Rosati
We present spectroscopic confirmation of nine moderate redshift galaxy groups and poor clusters selected from the ROSAT Deep Cluster Survey. The groups span the redshift range z=0.23-0.59 and have between 4 and 20 confirmed members. The velocity dispersions of these groups range from 125 to 650 km/s. Similar to X-ray groups at low redshift, these systems con
Bryan W. Miller
Recent work on globular cluster systems in dwarf galaxies outside the Local Group is reviewed. Recent large imaging surveys with the Hubble Space Telescope and follow-up spectroscopy with 8-m class telescopes now allow us to compare the properties of massive star clusters in a wide range of galaxy types and environments. This body of work provides important
Christopher Groppi, Christopher Walker, Craig Kulesa, Patrick Puetz
We report on the development of SuperCam, a 64 pixel, superheterodyne camera designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The advent of such a
I. Gavignaud, A. Bongiorno, S. Paltani, G. Mathez
We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey first observations of 21000 spectra in 1.75 square degree. This sample, which is purely magnitude limited, free of morphological or color selection biases, contains 130 broad line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (Iab
Bright Localized Near-Infrared Emission at 1-4 AU in the AB Aurigae Disk Revealed by IOTA Closure Phases
astro-phR. Millan-Gabet, J. D. Monnier, J. -P. Berger, W. A. Traub
We report on the detection of localized off-center emission at 1-4 AU in the circumstellar environment of the young stellar object AB Aurigae. We used closure phase measurements in the near-infrared made at the long baseline interferometer IOTA, the first obtained on a young stellar object using this technique. When probing sub-AU scales, all closure phases
Energy spectra of gamma-rays, electrons and neutrinos produced at proton-proton interactions in the very high energy regime
astro-phS. R. Kelner, F. A. Aharonian, V. V. Bugayov
We present new parametrisations of energy spectra of secondary particles, $π$-mesons, gamma-rays, electrons and neutrinos, produced in inelastic proton-proton collisions. The simple analytical approximations based on imulations of proton-proton interactions using the public available SIBYLL code, provide very good accuracy for energy distributions of seconda
K. M. Menten, S. D. Philipp, R. Guesten, J. Alcolea
Vibrationally excited emission from the SiO and H2O molecules probes the innermost circumstellar envelopes of oxygen-rich red giant and supergiant stars. VY CMa is the most prolific known stellar emission source in these molecules. Observations were made to search for rotational lines in the lowest vibrationally excited state of H2O. The APEX telescope was u
M. Bureau, G. Aronica, E. Athanassoula, R. -J. Dettmar
Kn-band images, unsharp-masked images, as well as major-axis and vertically- summed surface brightness profiles are presented for 30 edge-on spiral galaxies, most with a boxy or peanut-shaped (B/PS) bulge. Such galaxies have more complex morphologies than galaxies of other bulge types, more often showing (off-)centered X structures, secondary major-axis maxi
E. Forgacs-Dajka
We present detailed numerical calculations of the fast solar tachocline based on the assumption that the dynamo field dominates over the dynamics of the tachocline. In the present paper of the series, we focus on three shortfalls of the earlier models. First, instead of the simple oscillating dipole poloidal field we study the more general magnetic field str
Observations of the Hot Horizontal-Branch Stars in the Metal-Rich Bulge Globular Cluster NGC 6388 - Indications of Helium Enrichment and a Lesson in Crowded Field Spectroscopy
astro-phS. Moehler, A. V. Sweigart
(abridged) The metal-rich bulge globular cluster NGC6388 shows a distinct blue horizontal-branch tail with a strong upward tilt in its colour-magnitude diagram. Several noncanonical scenarios have been proposed to explain these puzzling observations. In order to test the predictions of these scenarios, we have obtained medium resolution spectra to determine
E. Forgacs-Dajka, B. Major, T. Borkovits
We studied the relation between the distribution of sunspot groups and the Gleissberg cycle. As the magnetic field is related to the area of the sunspot groups, we used area-weighted sunspot group data. On the one hand, we confirm the previously reported long-term cyclic behaviour of the sum of the northern and southern sunspot group mean latitudes, although
J. D. Monnier, J. -P. Berger, R. Millan-Gabet, W. Traub
Using the 3-telescope IOTA interferometer on Mt. Hopkins, we report results from the first near-infrared (lambda=1.65 mu) closure-phase survey of Young Stellar Objects (YSOs). These closure phases allow us to unambiguously detect departures from centrosymmetry (i.e., skew) in the emission pattern from YSO disks on the scale of ~4 milliarcseconds, expected fr
Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71: II. A search for intra-day variability at millimetre wavelengths with the IRAM 30 m telescope
astro-phI. Agudo, T. P. Krichbaum, H. Ungerechts, A. Kraus
We report on a densely time sampled polarimetric flux density monitoring of the BL Lac object S5 0716+71 at 86 GHz and 229 GHz with the IRAM 30 m telescope within a coordinated broad spectral band campaign, centred around an INTEGRAL observation during November 10 to 16, 2003. Our aim was to search for signatures of inverse-Compton "catastrophes". At
T. R. Jaffe, A. J. Banday, H. K. Eriksen, K. M. Gorski
Context. A specific example of Bianchi Type VIIh models, i.e. those including universal rotation (vorticity) and differential expansion (shear), has been shown in Jaffe et al. (2005) to correlate unexpectedly with the WMAP first-year data. Aims. We re-assess the signature of this model in the WMAP 3-year data. Methods. The cross-correlation methods are descr
F. Bensch, G. J. Melnick, D. A. Neufeld, M. Harwit
On 4 July 2005 at 5:52 UT the Deep Impact mission successfully completed its goal to hit the nucleus of 9P/Tempel 1 with an impactor, forming a crater on the nucleus and ejecting material into the coma of the comet. NASA's Submillimeter Wave Astronomy Satellite (SWAS) observed the 1(10)-1(01) ortho-water ground-state rotational transition in comet 9P/Tem
D. Iono, M. S. Yun, M. Elvis, A. Peck
We present ~3'' resolution imaging of the z=4.7 QSO BR1202-0725 at 900 micron from the Submillimeter Array. The two submillimeter continuum components are clearly resolved from each other, and the positions are consistent with previous lower frequency images. In addition, we detect [CII] line emission from the northern component. The ratio of [CII] t
T. Yoshida, T. Kajino, H. Yokomakura, K. Kimura
Neutrino oscillations affect light element synthesis through the neutrino-process in supernova explosions. The 7Li and 11B yields produced in a supernova explosion of a 16.2 solar-mass star model increase by factors of 1.9 and 1.3 in the case of large mixing angle solution with normal mass hierarchy and sin^{2}2theta_{13} > 0.002 compared with those without
P. Firth, M. J. Drinkwater, E. A. Evstigneeva, A. Karick
Our VLT (FLAMES) observations near NGC1399 investigate the connection between ultra-compact dwarf galaxies (UCDs), NGC1399 globular clusters and intra-cluster globulars. We have uncovered 30 faint compact stellar systems in the Fornax galaxy cluster, adding to 62 bright UCDs previously reported. The magnitude limit of these stellar systems extends down to th
Yumihiko Tsuzuki, Kimiaki Kawara, Yuzuru Yoshii, Shinki Oyabu
We present the spectra of 14 quasars with a wide coverage of rest wavelengths from 1000 to 7300 A. The redshift ranges from z = 0.061 to 0.555 and the luminosity from M_{B} = -22.69 to -26.32. We describe the procedure of generating the template spectrum of Fe II line emission from the spectrum of a narrow-line Seyfert 1 galaxy I Zw 1 that covers two wavelen
Nadya Gorlova, George H. Rieke, James Muzerolle, John R. Stauffer
We performed a 24 micron 2 Deg X 1 Deg survey of the Pleiades cluster, using the MIPS instrument on Spitzer. Fifty four members ranging in spectral type from B8 to K6 show 24 micron fluxes consistent with bare photospheres. All Be stars show excesses attributed to free-free emission in their gaseous envelopes. Five early-type stars and four solar-type stars
T. Yoshida, T. Kajino, H. Yokomakura, K. Kimura
Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the nu-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current nu-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a fa
Daniel Allcock
We explain a conjecture relating the monster simple group to an algebraic variety that was discovered in a non-monstrous context.
Xiao-Gang He, Tong Li, Xue-Qian Li, Yu-Ming Wang
We calculate the branching ratio of $Λ_b \to Λγ$ in the standard model using the PQCD method. The predicted branching ratio $B(Λ_b \to Λγ)$ is about $(4.3\sim 8.6)\times 10^{-8}$, with reasonable parameter ranges in the heavy baryon distribution amplitude. This branching ratio is much smaller than those obtained in other hadronic model calculations. Future e
Martin Schaller, Karl Svozil
Two novel computing models based on an infinite tessellation of space-time are introduced. They consist of recursively coupled primitive building blocks. The first model is a scale-invariant generalization of cellular automata, whereas the second one utilizes self-similar Petri nets. Both models are capable of hypercomputations and can, for instance, "so
W. E. Baylis, R. Cabrera, C. Rangan
Just as any state of a single qubit or 2-level system can be obtained from any other state by a rotation operator parametrized by three real Euler angles, we show how any state of an n-qubit or 2^n-level system can be obtained from any other by a compact unitary transformation with 2^(n+1)-1 real angles, 2^n of which are azimuthal-like and the rest polar-lik
E. van Beveren, D. V. Bugg, F. Kleefeld, G. Rupp
Masses and widths of the four light scalar mesons $σ$, $κ$, $a_0$(980) and $f_0$(980) may be reproduced in a model where mesons scatter via a $q\bar{q}$ loop. A transition potential is used to couple mesons to $q\bar{q}$ at a radius of $\sim 0.57$ fm. Inside this radius, there is an infinite bare spectrum of confined $q\bar{q}$ states, for which a harmonic o
Mark Hindmarsh, Petja Salmi
Oscillons, extremely long-living localized oscillations of a scalar field, are studied in theories with quartic and sine-Gordon potentials in two spatial dimensions. We present qualitative results concentrating largely on a study in frequency space via Fourier analysis of oscillations. Oscillations take place at a fundamental frequency just below the thresho
Sabir Umarov, Constantino Tsallis, Murray Gell-Mann, Stanly Steinberg
This paper is a continuation of papers \cite{UmarovTsallisSteinberg,UmarovTsallisGellmannSteinberg}. In Part I \cite{UmarovTsallisGellmannSteinberg} a description (representation) of $(q,α)$-stable distributions based on a $F_q$-transform was given. Here, in Part II, we present another description of these distributions. This approach generalizes results of
Gia-Wei Chern, C. J. Fennie, O. Tchernyshyov
We present a model describing the lattice distortion and incommensurate magnetic order in the spinel CdCr2O4, a good realization of the Heisenberg "pyrochlore" antiferromagnet. The magnetic frustration is relieved through the spin-Peierls distortion of the lattice involving a phonon doublet with odd parity. The distortion stablizes a collinear magnet
Sabir Umarov, Constantino Tsallis, Murray Gell-Mann, Stanly Steinberg
The classic central limit theorem and $α$-stable distributions play a key role in probability theory, and also in Boltzmann-Gibbs (BG) statistical mechanics. They both concern the paradigmatic case of probabilistic independence of the random variables that are being summed. A generalization of the BG theory, usually referred to as nonextensive statistical me
Hector Blandin, Rafael Diaz
We propose a categorical setting for the study of the combinatorics of rational numbers. We find combinatorial interpretation for the Bernoulli and Euler numbers and polynomials.
Roman G. Smirnov, Pavel Winternitz
We show that the three body Calogero model with inverse square potentials can be interpreted as a maximally superintegrable and multiseparable system in Euclidean three-space. As such it is a special case of a family of systems involving one arbitrary function of one variable.
Patrick McDonald
I compute a renormalization group (RG) improvement to the standard beyond-linear-order Eulerian perturbation theory (PT) calculation of the power spectrum of large-scale density fluctuations in the Universe. At z=0, for a power spectrum matching current observations, lowest order RGPT appears to be as accurate as one can test using existing numerical simulat
Martin Jelínek, Michael Prouza, Petr Kubánek, René Hudec
We present a discovery and observation of an extraordinarily bright prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 minutes after the GRB. We found rapid average temporal flux decay of alpha = -1.7 +- 0.1 and a peak brightness R = 10.1 mag. Later observatio
Anatoly Manita
We consider a basic stochastic particle system consisting of $N$ identical particles with isotropic $k$-particle synchronization, $k\geq 2$. In the limit when both number of particles $N$ and time $t=t(N)$ grow to infinity we study an asymptotic behavior of a coordinate spread of the particle system. We describe three time stages of $t(N)$ for which a qualit
Vadim M. Apalkov, Tapash Chakraborty
We have investigated the fractional quantum Hall states for the Dirac electrons in a graphene layer in different Landau levels. The relativistic nature of the energy dispersion relation of the electrons in the graphene significantly modifies the inter-electron interactions. This results in a specific dependence of the ground state energy and the energy gaps
Paul B. Slater
Wu and Sprung (Phys. Rev. E 48, 2595 (1993)) reproduced the first 500 nontrivial Riemann zeros, using a one-dimensional local potential model. They concluded -- and similarly van Zyl and Hutchinson (Phys. Rev. E 67, 066211 (2003)) -- that the potential possesses a fractal structure of dimension d=3/2. We model the nonsmooth fluctuating part of the potential
Christopher Spitzer
Mass-varying neutrino (MaVaN) models propose a source of dark energy in a new scalar field called the acceleron. Recent work has shown that nonrelativistic neutrino fields in these theories are unstable to inhomogeneous fluctuations, and form structures that no longer behave as dark energy. One might expect that in multiple-neutrino models, the lighter speci
Wolfgang A. Rolke, Angel M. Lopez
We describe a statistical hypothesis test for the presence of a signal based on the likelihood ratio statistic. We derive the test for a case of interest and also show that for that case the test works very well, even far out in the tails of the distribution. We also study extensions of the test to cases where there are multiple channels.
Mirjam Cvetic, Robert Richter
We analyze the proton decay via dimension six operators in supersymmetric SU(5)-Grand Unified models based on intersecting D6-brane constructions in Type IIA string theory orientifolds. We include in addition to 10* 10 10* 10 interactions also the operators arising from 5-bar* 5-bar 10* 10 interactions. We provide a detailed construction of vertex operators
J. L. McCauley, G. H. Gunaratne, K. E. Bassler
We show that our generalization of the Black-Scholes partial differential equation (pde) for nontrivial diffusion coefficients is equivalent to a Martingale in the risk neutral discounted stock price. Previously, this was proven for the case of the Gaussian logarithmic returns model by Harrison and Kreps, but we prove it for much a much larger class of retur
Joel Giedt
Lattice power-counting is extended to QCD with staggered fermions. As preparation, the difficulties encountered by Reisz's original formulation of the lattice power-counting theorem are illustrated. One of the assumptions that is used in his proof does not hold for staggered fermions, as was pointed out long ago by Luscher. Finally, I generalize the powe
Joseph L. McCauley
This article is a response to the recent Worrying Trends in Econophysics critique written by four respected theoretical economists. Two of the four have written books and papers that provide very useful critical analyses of the shortcomings of the standard textbook economic model, neo-classical economic theory and have even endorsed my book. Largely, their n
Kaustubh Agashe, Andrew E. Blechman, Frank Petriello
The ``anarchic'' Randall-Sundrum model of flavor is a low energy solution to both the electroweak hierarchy and flavor problems. Such models have a warped, compact extra dimension with the standard model fermions and gauge bosons living in the bulk, and the Higgs living on or near the TeV brane. In this paper we consider bounds on these models set by
L. Escauriaza
We describe a formula for the Taylor series expansion of the Gaussian kernel around the origin of $\Rn\times\R$.
J. P. Hague, P. E. Kornilovitch, J. H. Samson, A. S. Alexandrov
We study a lattice bipolaron on a staggered triangular ladder and triangular and hexagonal lattices with both long-range electron-phonon interaction and strong Coulomb repulsion using a novel continuous-time quantum Monte-Carlo (CTQMC) algorithm extended to the Coulomb-Frohlich model with two particles. The algorithm is preceded by an exact integration over
Kayll Lake
We examine, in a purely geometrical way, static Ricci-flat 5-manifolds admitting the 2-sphere and an additional hypersurface-orthogonal Killing vector. These are widely studied in the literature, from different physical approaches, and known variously as the Kramer - Gross - Perry - Davidson - Owen solutions. The 2-fold infinity of cases that result are stud
J. Gegenberg, G. Kunstatter, R. D. Small
We describe a midi-superspace quantization scheme for generic single horizon black holes in which only the spatial diffeomorphisms are fixed. The remaining Hamiltonian constraint yields an infinite set of decoupled eigenvalue equations: one at each spatial point. The corresponding operator at each point is the product of the outgoing and ingoing null converg
Gianluca Calcagni, Andrew R. Liddle
We explore the dynamics of dark energy models based on a Dirac-Born-Infeld (DBI) tachyonic action, studying a range of potentials. We numerically investigate the existence of tracking behaviour and determine the present-day value of the equation of state parameter and its running, which are compared with observational bounds. We find that tachyon models have
Joan A. Smith, Martin Klein, Michael L. Nelson
We present the results of a feasibility study using shared, existing, network-accessible infrastructure for repository replication. We investigate how dissemination of repository contents can be ``piggybacked'' on top of existing email and Usenet traffic. Long-term persistence of the replicated repository may be achieved thanks to current policies an
Simulating Anisotropic Thermal Conduction in Supernova Remnants I : Numerics and the Evolution of Remnants
astro-phD. S. Balsara, D. A. Tilley, J. C. Howk
Anisotropic thermal conduction plays an important role in various astrophysical systems. One of the most stringent tests of thermal conduction can be found in supernova remnants. In this paper we study anisotropic thermal conduction and examine the physical nature of the flux of thermal conduction in the classical and saturated limits. We also present a temp
Bogusz Kinasiewicz, Patryk Mach, Edward Malec
The selfgravity of an infalling gas can alter significantly the accretion of gases. In the case of spherically symmetric steady flows of polytropic perfect fluids the mass accretion rate achieves maximal value when the mass of the fluid is 1/3 of the total mass. There are two weakly accreting regimes, one over-abundant and the other poor in fluid content. Th
Mette B. Gaarde, Mitsuko Murakami, Reinhard Kienberger
We study the temporal and spatial dynamics of the large amplitude and frequency modulation that can be induced in an intense, few cycle laser pulse as it propagates through a rapidly ionizing gas. Our calculations include both single atom and macroscopic interactions between the non-linear medium and the laser field. We analyze the harmonic generation by suc
Viv Kendon
The development of quantum walks in the context of quantum computation, as generalisations of random walk techniques, led rapidly to several new quantum algorithms. These all follow unitary quantum evolution, apart from the final measurement. Since logical qubits in a quantum computer must be protected from decoherence by error correction, there is no need t
Experimental study of the transport of coherent interacting matter-waves in a 1D random potential induced by laser speckle
cond-mat.otherDavid Clément, Andrès F. Varòn, Jocelyn A. Retter, Laurent Sanchez-Palencia
We present a detailed analysis of the 1D expansion of a coherent interacting matterwave (a Bose-Einstein condensate) in the presence of disorder. A 1D random potential is created via laser speckle patterns. It is carefully calibrated and the self-averaging properties of our experimental system are discussed. We observe the suppression of the transport of the
Zhaohui Wei, Zhengfeng Ji, Mingsheng Ying
The majorization theory has been applied to analyze the mathematical structure of quantum algorithms. An empirical conclusion by numerical simulations obtained in the previous literature indicates that step-by-step majorization seems to appear universally in quantum adiabatic algorithms. In this paper, a rigorous analysis of the majorization arrow in a speci
Wei-Shu Hou
The X(3872) and Y(4260), among a host of charmonium-like mesons, have rather unusual properties: the former has very small total width, the latter has large rate into $π^+π^-J/ψ$ channel. It would not be easy to settle between the many suggested explanations for their composition. We point out that discovering the bottom counterparts should shed much light o