November 2008 arXiv papers — page 34
Showing 3,301–3,400 of 4,899 papers
Discovery of photospheric CaX emission lines in the far-UV spectrum of the hottest known white dwarf (KPD0005+5106)
astro-phK. Werner, T. Rauch, J. W. Kruk
For the first time, we have identified photospheric emission lines in the far-UV spectrum of a white dwarf. They were discovered in the Far Ultraviolet Spectroscopic Explorer spectrum of the hot (Teff~200,000 K) DO white dwarf KPD0005+5106 and they stem from extremely highly ionized calcium (CaX 1137, 1159 Ang). Their photospheric origin is confirmed by non-
Dmitri V. Alekseevsky, Vicente Cortés
We give an intrinsic definition of (affine very) special real manifolds and realise any such manifold $M$ as a domain in affine space equipped with a metric which is the Hessian of a cubic polynomial. We prove that the tangent bundle $N=TM$ carries a canonical structure of (affine) special Kähler manifold. This gives an intrinsic description of the $r$-map a
Unconventional superconductivity originating from disconnected Fermi surfaces in the iron-based compound
cond-mat.supr-conHideo Aoki
The iron-based LaFeAsO$_{1-x}$F$_x$ recently discovered by Hosono's group is a fresh theoretical challenge as a new class of high-temperature superconductors. Here we describe the electronic structure of the material and the mechanism of superconductivity. We start with constructing a tight-binding model in terms of the maximally localized Wannier orbita
Tornike Kadeishvili
In the rational cohomology of a 1-connected space a structure of $C_{\infty}$-algebra is constructed and it is shown that this object determines the rational homotopy type
S. Bardelli, E. Zucca, M. Bolzonella, P. Ciliegi
(abridged) We use the 1.4 GHz VIMOS-VLA Deep Survey and the optical VVDS and the CFHT-LS to compare the properties of radio loud galaxies with respect to the whole population of optical galaxies. The availability of multiband photometry and high quality photometric redshifts allows to derive rest frame colors and radio luminosity functions down to a limit of
M. Brozos-Vazquez, P. Gilkey, H. Kang, S. Nikcevic
We show any Riemannian curvature model can be geometrically realized by a manifold with constant scalar curvature. We also show that any pseudo-Hermitian curvature model, para-Hermitian curvature model, hyper-pseudo-Hermitian curvature model, or hyper-para-Hermitian curvature model can be realized by a manifold with constant scalar and *-scalar curvature.
Stationary transport in mesoscopic hybrid structures with contacts to superconducting and normal wires. A Green's function approach for multiterminal setups
cond-mat.mes-hallLiliana Arrachea
We generalize the representation of the real time Green's functions introduced by Langreth and Nordlander [Phys. Rev. B 43 2541 (1991)] and Meir and Wingreen [Phys. Rev. Lett. 68 2512 (1992)] in stationary quantum transport in order to study problems with hybrid structures containing normal (N) and superconducting (S) pieces. We illustrate the treatment
Hemant Ishwaran, Udaya B. Kogalur, Eugene H. Blackstone, Michael S. Lauer
We introduce random survival forests, a random forests method for the analysis of right-censored survival data. New survival splitting rules for growing survival trees are introduced, as is a new missing data algorithm for imputing missing data. A conservation-of-events principle for survival forests is introduced and used to define ensemble mortality, a sim
Seokcheon Lee
It is well known that the viscous Bianchi type-I metric of the Kasner form is not able to describe an anisotropic universe, which satisfies the second law of thermodynamics and the dominant energy condition in Einstein's theory of gravity. We investigate this problem in Brans-Dicke theory of gravity using the Bianchi type-I metric with the perfect fluid.
The Keck Aperture Masking Experiment: spectro-interferometry of 3 Mira Variables from 1.1 to 3.8 microns
astro-phH. C. Woodruff, M. J. Ireland, P. G. Tuthill, J. D. Monnier
We present results from a spectro-interferometric study of the Miras o Cet, R Leo and W Hya obtained with the Keck Aperture Masking Experiment from 1998 Sep to 2002 Jul. The spectrally dispersed visibility data permit fitting with circularly symmetric brightness profiles such as a simple uniform disk. The stellar angular diameter obtained over up to ~ 450 sp
Donald B. Rubin
For obtaining causal inferences that are objective, and therefore have the best chance of revealing scientific truths, carefully designed and executed randomized experiments are generally considered to be the gold standard. Observational studies, in contrast, are generally fraught with problems that compromise any claim for objectivity of the resulting causa
Zahid Ahmad, Tomohiro Harada, Ken-ichi Nakao, M. Sharif
In this paper, we study the dynamics of a hollow spherical matter collapsing with very large initial velocity. The spacetime is initially very similar to the Vaidya solution, and the deviations from this background are treated perturbatively. The equations of state for radial pressure $p_{\rm R}=kρ$ and tangential one $p_{\rm T}=wρ$ with constant $k$ and $w$
Bulk-edge correspondence in graphene with/without magnetic field: Chiral symmetry, Dirac fermions and Edge states
cond-mat.mes-hallY. Hatsugai
There are two types of edge states in graphene with/without magnetic field. One is a quantum Hall edge state, which is topologically protected against small perturbation. The other is a chiral zero mode that is localized near the boundary with/without magnetic field. The latter is also topological but is guaranteed to be zero energy by the chiral symmetry, w
Hua-Shu Dou, Boo Cheong Khoo
Experiments have shown that in dilute suspension flow at laminar state through a circular tube particles migrate towards a concentric annular region with a mean radius of about 0.6 of the tube radius. This phenomenon is well-known as the tubular pinch effect, which is still not fully understood. In this study, the energy gradient method is used to study this
Incipient Separation in Shock Wave Boundary Layer Interactions as Induced by Sharp Fin
physics.flu-dynHua-Shu Dou, Boo Cheong Khoo, Khoon Seng Yeo
The incipient separation induced by the shock wave turbulent boundary layer interaction at the sharp fin is the subject of present study. Existing theories for the prediction of incipient separation, such as those put forward by McCabe (1966) and Dou and Deng (1992), can have thus far only predicting the direction of surface streamline and tend to over-predi
Y. Tsue, K. Matsuda
The chiral phase transition at finite temperature is investigated in the linear sigma model, which is regarded as a low energy effective theory of QCD with three momentum cutoff, in the variational method with the Gaussian approximation in the functional Schroedinger picture. It is shown that the Goldstone theorem is retained and the meson pair excitations a
Mehryar Mohri, Afshin Rostamizadeh
Most generalization bounds in learning theory are based on some measure of the complexity of the hypothesis class used, independently of any algorithm. In contrast, the notion of algorithmic stability can be used to derive tight generalization bounds that are tailored to specific learning algorithms by exploiting their particular properties. However, as in m
Ground-State Properties of a Heisenberg Spin Glass Model with a Hybrid Genetic Algorithm
cond-mat.dis-nnYuh-ichi Iyama, Fumitaka Matsubara
We developed a genetic algorithm (GA) in the Heisenberg model that combines a triadic crossover and a parameter-free genetic algorithm. Using the algorithm, we examined the ground-state stiffness of the $\pm J$ Heisenberg model in three dimensions up to a moderate size range. Results showed the stiffness constant of $θ= 0$ in the periodic-antiperiodic bounda
Yoshimasa Matsuno
A novel method is developed for constructing periodic solutions of a model equation describing nonlocal Josephson electrodynamics. This method consists of reducing the equation to a system of linear ordinary differential equations through a sequence of nonlinear transformations. The periodic solutions are then obtained by a standard procedure which are repre
Hiromi Saida
When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, due to the net energy flow, the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net en
David W. Kribs, Aron Pasieka, Karol Zyczkowski
We define and investigate a notion of entropy for quantum error correcting codes. The entropy of a code for a given quantum channel has a number of equivalent realisations, such as through the coefficients associated with the Knill-Laflamme conditions and the entropy exchange computed with respect to any initial state supported on the code. In general the en
Stationary Configurations Imply Shift Symmetry: No Bondi Accretion for Quintessence / k-Essence
astro-phRatindranath Akhoury, Christopher S. Gauthier, Alexander Vikman
In this paper we show that, for general scalar fields, stationary configurations are possible for shift symmetric theories only. This symmetry with respect to constant translations in field space should either be manifest in the original field variables or reveal itself after an appropriate field redefinition. In particular this result implies that neither k
C. Samanta
Magic islands for extra-stable nuclei in the midst of the sea of fission-instability were predicted to be around Z=114, 124 or, 126 with N=184, and Z=120, with N=172. Whether these fission-survived superheavy nuclei with high Z and N would live long enough for detection or, undergo alpha-decay in a very short time remains an open question. Alpha-decay half l
Chendong Li
Airport gate assignment is of great importance in airport operations. In this paper, we study the Airport Gate Assignment Problem (AGAP), propose a new model and implement the model with Optimization Programming language (OPL). With the objective to minimize the number of conflicts of any two adjacent aircrafts assigned to the same gate, we build a mathemati
Spin susceptibility, phase diagram, and quantum criticality in the electron-doped high Tc Superconductor Ba[Fe(1-x)Co(x)]2As2
cond-mat.supr-conF. L. Ning, K. Ahilan, T. Imai, A. S. Sefat
We report a systematic investigation of Ba[Fe(1-x)Co(x)]2As2 based on transport and 75-As NMR measurements, and establish the electronic phase diagram. We demonstrate that doping progressively suppresses the uniform spin susceptibility and low frequency spin fluctuations. The optimum superconducting phase emerges at x_c~0.08 when the tendency toward spin ord
Hiroshi Ueda, Hiroki Nakano, Koichi Kusakabe
We have developed a numerical procedure to clarify the critical behavior near a quantum phase transition by analyzing a multi-point correlation function characterizing the ground state. This work presents a successful application of this procedure to the string order parameter of the S = 1 XXZ chain with uniaxial single-ion anisotropy. The finite-size string
Chang Eon Shin, Qiyu Sun
Let $\ell^p, 1\le p\le \infty$, be the space of all $p$-summable sequences and $C_a$ be the convolution operator associated with a summable sequence $a$. It is known that the $\ell^p$- stability of the convolution operator $C_a$ for different $1\le p\le \infty$ are equivalent to each other, i.e., if $C_a$ has $\ell^p$-stability for some $1\le p\le \infty$ th
Alexis Diaz-Torres, David Hinde, Mahananda Dasgupta, Gerard Milburn
A novel quantum dynamical model based on the dissipative quantum dynamics of open quantum systems is presented. It allows the treatment of both deep-inelastic processes and quantum tunneling (fusion) within a fully quantum mechanical coupled-channels approach. Model calculations show the transition from pure state (coherent) to mixed state (decoherent and di
Hua Jiang, Shuguang Cheng, Qing-feng Sun, X. C. Xie
The influence of dephasing on the quantum spin Hall effect (QSHE) is studied. In the absence of dephasing, the longitudinal resistance in a QSHE system exhibits the quantum plateaus. We find that these quantum plateaus are robust against the normal dephasing but fragile with the spin dephasing. Thus, these quantum plateaus only survive in mesoscopic samples.
Yanxia Xing, Qing-feng Sun, Jian Wang
Electron charge transport through a quantum point contact (QPC) driven by an asymmetric spin bias is studied. A large charge current is induced when the transmission coefficient of the QPC jumps from one integer plateau to the next. Furthermore, for an open external circuit, the induced charge bias instead of the charge current is found to be quite large. It
P. González, P. Ladrón de Guevara, E. López Torres, A. Marín
We present Monte Carlo preliminary results about the feasibility to detect the Chic family in p-p collisions at 14 TeV in the ALICE Central Barrel at CERN LHC. The Chic1 and Chic2 were forced to decay in the channel J/Psi + gamma -> e+ e- + gamma and were merged with a proton-proton non-biased collision. After MonteCarlo transport and simulation of the detec
Paulo Amorim, Christine Bernardi, Philippe G. LeFloch
We consider a system of nonlinear wave equations with constraints that arises from the Einstein equations of general relativity and describes the geometry of the so-called Gowdy symmetric spacetimes on T3. We introduce two numerical methods, which are based on pseudo-spectral approximation. The first approach relies on marching in the future time-like direct
Xinjia Chen
In this paper, we develop a computational approach for estimating the mean value of a quantity in the presence of uncertainty. We demonstrate that, under some mild assumptions, the upper and lower bounds of the mean value are efficiently computable via a sample reuse technique, of which the computational complexity is shown to posses a Poisson distribution.
Simon Caron-Huot
We consider the bremsstrahlung energy loss of high energy partons moving in the quark-gluon plasma, at weak coupling. We show that the rates for these processes receive large O(g) corrections from classical (nonabelian) plasma physics effects, which are calculated. In the high-energy (deep LPM) regime these corrections can be absorbed in a change of the tran
L. E. Ibanez, R. Richter
Type IIA orientifold constructions with intersecting D6-branes and their IIB duals in terms of magnetized D9/D7-branes constitute one of the most promising avenues for the construction of semirealistic MSSM-like compactifications. One generic problem with these constructions is, that there are many Yukawa couplings, which vanish due to additional U(1) symmet
Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik
We study the Galactic field population of double compact objects (NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with LISA at low gravitational-wave frequencies. We calculate the Galactic numbers and physical properties of these binaries and show their relative contribution from the disk, bu
C. Hess, A. Kondrat, A. Narduzzo, J. E. Hamann-Borrero
We present the first comprehensive derivation of the intrinsic electronic phase diagram of the iron-oxypnictide superconductors in the normal state based on the analysis of the electrical resistivity $ρ$ of both LaFeAsO$_{1-x}$F$_x$ and SmFeAsO$_{1-x}$F$_x$ for a wide range of doping. Our data give clear-cut evidence for unusual normal state properties in th
Lorenzo Ubaldi
We study the effects that a non zero strong-CP-violating parameter theta would have on the deuteron and diproton binding energies and on the triple-alpha process. Both these systems exhibit fine tuning, so it is plausible that a small change in the nuclear force would produce catastrophic consequences. Such a nuclear force is here understood in the framework
Thomas Flacke, A. Menon, Daniel J. Phalen
In this paper we investigate the phenomenological implications of boundary localized terms (BLTs) in the model of Universal Extra Dimensions (UED). In particular, we study the electroweak Kaluza-Klein mass spectrum resulting from BLTs and their effect on electroweak symmetry breaking via the five dimensional Higgs mechanism. We find that the addition of BLTs
Vincenzo Tamma, Heyi Zhang, Xuehua He, Augusto Garuccio
In this paper, we will describe a new factorization algorithm based on the continuous representation of Gauss sums, generalizable to orders j>2. Such an algorithm allows one, for the first time, to find all the factors of a number N in a single run without precalculating the ratio N/l, where l are all the possible trial factors. Continuous truncated exponent
G. Risaliti, M. Salvati, M. Elvis, G. Fabbiano
We present an analysis of the extreme obscuration variability observed during an XMM-Newton 5-days continuous monitoring of the AGN in NGC 1365. The source was in a reflection-dominated state in the first ~1.5 days, then a strong increase of the 7-10 keV emission was observed in ~10 hours, followed by a symmetric decrease. The spectral analysis of the differ
Marisa Zymonopoulou
The Busemann-Petty problem asks whether origin symmetric convex bodies in $\R^n$ with smaller hyperplane sections necessarily have smaller volume. The answer is affirmative if $n\leq 3$ and negative if $n\geq 4.$ We consider a class of convex bodies that have a certain invariance property with respect to their ordered k-tuples of coordinates in $\R^{kn}$ and
Thomas Barnet-Lamb
We consider the one-parameter family of hypersurfaces in $\Pj^5$ with projective equation (X_1^5+X_2^5+X_3^5+X_4^5+X_5^5) = 5λX_1 X_2... X_5, (writing $λ$ for the parameter), proving that the Galois representations attached to their cohomologies are potentially automorphic, and hence that the zeta function of the family has meromorphic continuation throughou
Kim Maltman
The interpretation of results of recent tau decay determinations of |V_us|, which yield values ~3 sigma low compared to 3-family unitarity expectations, is complicated by the slow convergence of the relevant integrated D=2 OPE series. We introduce a class of sum rules involving both electroproduction and tau decay data designed to deal with this problem by s
Thomas Barnet-Lamb
Building upon work of Clozel, Harris, Shepherd-Barron, and Taylor, this paper shows that certain Galois representations become automorphic after one makes a suitably large totally-real extension to the base field. The main innovation here is that the result applies to Galois representations to GL_{2n}, where previous work dealt with representations to GSp_n.
Serban Belinschi, Amir Dembo, Alice Guionnet
We study the asymptotic behavior of the appropriately scaled and possibly perturbed spectral measure $μ$ of large random real symmetric matrices with heavy tailed entries. Specifically, consider the N by N symmetric matrix $Y_N^σ$ whose (i,j) entry is $σ(i/N,j/N)X_{ij}$ where $(X_{ij}, 0<i<j+1<\infty)$ is an infinite array of i.i.d real variables with common
Jorge Penarrubia, Julio F. Navarro, Alan W. McConnachie, Nicolas F. Martin
(Abridged) We use N-body simulations to explore the effects of tidal stripping on the structure of dwarf spheroidal galaxies (dSphs). We model dSphs as King spheres embedded in NFW dark halos that orbit the Galactic potential on eccentric orbits. We find that episodes of stellar mass loss remove the initial cutoff of the bound stellar core. Once equilibrium
Global phase diagrams of frustrated quantum antiferromagnets in two dimensions: doubled Chern-Simons theory
cond-mat.str-elCenke Xu, Subir Sachdev
We present a general approach to understanding the quantum phases and phase transitions of quantum antiferromagnets in two spatial dimensions. We begin with the simplest spin liquid state, the Z_2 spin liquid, whose elementary excitations are spinons and visons, carrying Z_2 electric and magnetic charges respectively. Their dynamics are expressed in terms of
Nirupam Roy, Somnath Bharadwaj, Prasun Dutta, Jayaram N. Chengalur
We present estimates of the angular power spectra of the synchrotron radiation intensity fluctuations at 6 and 20 cm for the shell type supernova remnant Cas A and the filled-centre Crab supernova remnant. We find that the intensity fluctuations of both sources have a power law power spectrum with index -3.24 +/- 0.03. This power law power spectrum is consis
Roger Züst
For an oriented $n$-dimensional Lipschitz manifold $M$ we give meaning to the integral $\int_M f dg_1 \wedge ... \wedge dg_n$ in case the functions $f, g_1, >..., g_n$ are merely Hölder continuous of a certain order by extending the construction of the Riemann-Stieltjes integral to higher dimensions. More generally, we show that for $α\in (\frac{n}{n+1},1]$
Jacquelyn Noronha-Hostler, Jorge Noronha, Carsten Greiner
A hadron resonance gas model including all known particles and resonances with masses $m<2$ GeV and an exponentially rising density of Hagedorn states for $m>2$ GeV is used to obtain an upper bound on the shear viscosity to entropy density ratio, $η/s\approx1/(4π)$, of hadronic matter near $T_c$. We found a large trace anomaly and small speed of sound near $
Tamas Hausel
We prove a generating function formula for the Betti numbers of Nakajima quiver varieties. We prove that it is a q-deformation of the Weyl-Kac character formula. In particular this implies that the constant term of the polynomial counting the number of absolutely indecomposable representations of a quiver equals the multiplicity of a a certain weight in the
Superintegrability with third order integrals of motion, cubic algebras and supersymmetric quantum mechanics II:Painleve transcendent potentials
math-phIan Marquette
We consider a superintegrable quantum potential in two-dimensional Euclidean space with a second and a third order integral of motion. The potential is written in terms of the fourth Painleve transcendent. We construct for this system a cubic algebra of integrals of motion. The algebra is realized in terms of parafermionic operators and we present Fock type
Stéphanie Cupit-Foutou
The invariant Hilbert schemes considered in \cite{BC1} were proved to be affine spaces. The proof relied on the classification of strict wonderful varieties. We obtain in the present article a classification-free proof of the affinity of these invariant Hilbert scheme by means of deformation theoretical arguments. As a consequence we recover in a shorter way
Jaume Gomis, Dmitri Sorokin, Linus Wulff
We lift the bosonic AdS_4 x CP^3 solution of type IIA supergravity preserving 24 supersymmetries to a D=10 superspace which has 32 Grassmann-odd directions. The type IIA superspace is obtained from D=11 via dimensional reduction of the coset superspace OSp(8|4)/SO(7) x SO(1,3) by realizing the latter as a Hopf fibration over the former. This construction gen
De-Chang Dai, Reijiro Matsuo, Glenn Starkman
We investigate the consequences of Birkhoff's theorem in general relativity (GR) and in Modified Newtonian dynamics (MOND). We study, in particular, the system of a finite-mass test particle inside a spherical shell. In both GR and MOND, we find non-vanishing acceleration for that test particle. The direction of the acceleration is such that it pushes th
Time Series Technical Analysis via New Fast Estimation Methods: A Preliminary Study in Mathematical Finance
stat.APMichel Fliess, Cédric Join
New fast estimation methods stemming from control theory lead to a fresh look at time series, which bears some resemblance to "technical analysis". The results are applied to a typical object of financial engineering, namely the forecast of foreign exchange rates, via a "model-free" setting, i.e., via repeated identifications of low order lin
Matthew J. Strassler
A recent paper by the CDF collaboration suggests (but does not claim) an anomalous event sample containing muons produced with large impact parameter, often with high multiplicity and at small angles from one another. This curious hint of a signal is potentially consistent with the hidden valley scenario, as well as with some other classes of models. Despite
Swagato Banerjee
Several hundred million tau decays have been studied with the BaBar detector at the PEP-II e+e- collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V_{us}| using tau- -> e- nubar nu, mu- nubar nu, pi- nu, K- nu and KS0 pi- nu decays, and a search for Second Class Cur
Pawel Danielewicz, Jenny Lee
Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula. Charge symmetry of the nuclear interactions allows to introduce isoscalar and isovector densities that are approximately
M. Renaud, S. Hoppe, N. Komin, E. Moulin
H.E.S.S. is currently the most sensitive instrument in the very-high-energy gamma-ray domain and has revealed many new sources along the Galactic Plane, a significant fraction of which seems to be associated with energetic pulsars. HESS J1825-137 and Vela X are considered to be the prototypes of such sources in which the large VHE nebula results from the who
S. Krohns, P. Lunkenheimer, Ch. Kant, A. V. Pronin
The search for new materials with extremely high ("colossal") dielectric constants, required for future electronics, is one of the most active fields of modern materials science. However, the applicability of the colossal-epsilon' materials, discovered so far, suffers from the fact that their dielectric constant, epsilon', only is huge in a l
László Árpád Gergely, Narit Pidokrajt, Sergei Winitzki
Tidal charged spherically symmetric vacuum brane black holes are characterized by their mass m and tidal charge q, an imprint of the 5-dimensional Weyl curvature. For q>0 they are formally identical to the Reissner-Nordström black hole of general relativity. We study the thermodynamics and thermodynamic geometries of tidal charged black holes and discuss sim
On the nature of HESS J1503-582 revealed by the H.E.S.S. experiment: Coincidence with a FVW?
astro-phM. Renaud, P. Goret, R. C. G. Chaves
The H.E.S.S. survey of the inner Galaxy in the very-high-energy gamma-ray domain has led to the discovery of many extended sources, some of which do not appear to be associated with any obvious counterpart at traditional wavelengths (radio, infrared and X-ray). In this contribution, preliminary H.E.S.S. results on one of these so-called "dark" sources, namel
Suppression or enhancement of the Fulde-Ferrell-Larkin-Ovchinnikov order in a one-dimensional optical lattice with particle correlated tunnelling
quant-phB. Wang, L. -M. Duan
We study through controlled numerical simulation the ground state properties of spin-polarized strongly interacting fermi gas in an anisotropic optical lattice, which is described by an effective one-dimensional general Hubbard model with particle correlated hopping rate. We show that the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) type of state, while enhanced
Yves de Cornulier, Luc Guyot, Wolfgang Pitsch
We carry out the Cantor-Bendixson analysis of the space of all subgroups of any countable abelian group and we deduce a complete classification of such spaces up to homeomorphism.
Family of boron fullerenes: general constructing schemes, electron counting rule and ab initio calculations
cond-mat.mtrl-sciQing-Bo Yan, Xian-Lei Sheng, Qing-Rong Zheng, Li-Zhi Zhang
A set of general constructing schemes is unveiled to predict a large family of stable boron monoelemental, hollow fullerenes with magic numbers 32+8k (k>=0). The remarkable stabilities of these new boron fullerenes are then studied by intense ab initio calculations. An electron counting rule as well as an isolated hollow rule are proposed to readily show the
Energy-scale phenomenology and pairing via resonant spin-charge motion in FeAs, CuO, heavy-fermion and other exotic superconductors
cond-mat.supr-conY. J. Uemura
Muon spin relaxation ($μ$SR) studies of the "1111" and "122" FeAs systems have detected static magnetism with variably sized ordered moments in their parent compounds. The phase diagrams of FeAs, CuO, organic BEDT, A$_{3}$C$_{60}$ and heavy-fermion systems indicate competition between static magnetism and superconductivity, associated with fi
E. Antonyan, A. A. Tseytlin
We elaborate on the suggestion made in arXiv:0806.3498 that the 3d \N=8 superconformal SU(N) Chern-Simons-matter theory of Lorentzian Bagger-Lambert-Gustavson type (L-BLG) can be obtained by a scaling limit (involving sending the level k to infinity and redefining the fields) from the \N=6 superconformal U(N)xU(N) Chern-Simons-matter theory of Aharony, Bergm
Feedback and Fluctuations in a Totally Asymmetric Simple Exclusion Process with Finite Resources
cond-mat.stat-mechL. Jonathan Cook, R. K. P. Zia
We revisit a totally asymmetric simple exclusion process (TASEP) with open boundaries and a global constraint on the total number of particles [Adams, et. al. 2008 J. Stat. Mech. P06009]. In this model, the entry rate of particles into the lattice depends on the number available in the reservoir. Thus, the total occupation on the lattice feeds back into its
J. Fernandez Bonder, J. P. Pinasco
In this work we study the sequence of variational eigenvalues of a system of resonant type involving $p-$ and $q-$laplacians on $Ω\subset \R^N$, with a coupling term depending on two parameters $α$ and $β$ satisfying $α/p + β/q = 1$. We show that the order of growth of the $k^{th}$ eigenvalue depends on $α+β$, $\lam_k = O(k^{\frac{α+β}{N}})$.
Cezary Migaszewski, Krzysztof Gozdziewski, Tobias C. Hinse
We investigate the dynamics of putative Earth-mass planets in the habitable zone (HZ) of the extrasolar planetary system OGLE-2006-BLG-109L, a close analog of the Solar system. Our work is inspired by work of Malhotra and Minton (2008). Using the linear Laplace-Lagrange theory, they identified a strong secular resonance that may excite large eccentricity of
J. Larson, A. Collin, J. -P. Martikainen
We study a gas of repulsively interacting bosons in an optical lattice and explore the physics beyond the lowest band Hubbard model. Utilizing a generalized Gutzwiller ansatz, we find how the lowest band physics is modified by the inclusion of the first excited bands. In contrast to the prediction of the lowest band Bose-Hubbard model, a reentrant behavior o
Hanfeng Li
We show that every infinite-dimensional commutative unital C*-algebra has a Hilbert C*-module admitting no frames. In particular, this shows that Kasparov's stabilization theorem for countably generated Hilbert C*-modules can not be extended to arbitrary Hilbert C*-modules.
Lev Steinberg
The purpose of this paper is to present a new mathematical model for the deformation of thin Cosserat elastic plates. Our approach, which is based on a generalization of the classical Reissner plate theory, takes into account the transverse variation of microrotation of the plates. The model assumes polynomial approximations over the plate thickness of asymm
Richard Randell
Recent work of M. Yoshinaga shows that in some instances certain higher homotopy groups of arrangements map onto non-resonant homology. This is in contrast to the usual Hurewicz map to untwisted homology, which is always the zero homomorphism in degree greater than one. In this work we examine this dichotomy, generalizing both results.
Marco Tomamichel, Roger Colbeck, Renato Renner
The classical asymptotic equipartition property is the statement that, in the limit of a large number of identical repetitions of a random experiment, the output sequence is virtually certain to come from the typical set, each member of which is almost equally likely. In this paper, we prove a fully quantum generalization of this property, where both the out
Benjamin Steinhurst
In this paper we explore two constructions of the same family of metric measure spaces. The first construction was introduced by Laakso in 2000 where he used it as an example that Poincaré inequalities can hold on spaces of arbitrary Hausdorff dimension. This was proved using minimal generalized upper gradients. Following Cheeger's work these upper gradi
Jun Lu, Mao Sheng, Kang Zuo
In this paper we show an Arakelov inequality for semi-stable families of algebraic curves of genus $g\geq 1$ over characteristic $p$ with nontrivial Kodaira-Spencer maps. We apply this inequality to obtain an upper bound of the number of algebraic curves of $p-$rank zero in a semi-stable family over characteristic $p$ with nontrivial Kodaira-Spencer map in t
Choon-Lin Ho
In supersymmetric quantum mechanics, exact-solvability of one-dimensional quantum systems can be classified only with an additional assumption of integrability, the so-called shape invariance condition. In this paper we show that in the prepotential approach we proposed previously, shape invariance is automatically satisfied and needs not be assumed.
Christian Gollwitzer, Marina Krekhova, Guenter Lattermann, Ingo Rehberg
We report on the formation of surface instabilities in a layer of thermoreversible ferrogel when exposed to a vertical magnetic field. Both static and time dependent magnetic fields are employed. Under variations of temperature, the viscoelastic properties of our soft magnetic matter can be tuned. Stress relaxation experiments unveil a stretched exponential
Giorgio Parisi, Tommaso Rizzo
We consider the probability distribution of large deviations in the spin-glass free energy for the Sherrington-Kirkpatrick mean field model, i.e. the exponentially small probability of finding a system with intensive free energy smaller than the most likely one. This result is obtained by computing $Φ(n,T)=T \bar{Z^n}/ n$, i.e. the average value of the parti
Multi-wavelength Calibration Procedure for the Pierre Auger Observatory Fluorescence Detectors
astro-phA. C. Rovero, P. Bauleo, J. T. Brack, J. L. Harton
We present a method to measure the relative spectral response of the Pierre Auger Observatory Fluorescence Detector. The calibration was done at wavelengths of 320, 337, 355, 380 and 405 nm using an end-to-end technique in which the response of all detector components are combined in a single measurement. A xenon flasher and notch-filters were used as the li
H. Abuki, M. Ciminale, R. Gatto, M. Ruggieri
We elucidate how the color neutrality is harmed in the Polyakov Nambu-Jona Lasinio (PNJL) model at finite density within the adopted mean field approximation. Also we point out how usual assumption about the diagonal form of the Wilson loop may fail in the presence of the diquark condensate on several grounds.
René Heller, Derek Homeier, Stefan Dreizler, Roy Østensen
We present a catalog of 857 white dwarf (WD)-M binaries from the sixth data release (DR6) of the Sloan Digital Sky Survey (SDSS), most of which were previously identified. For 636 of them, we complete a spectral analysis and derive the basic parameters of their stellar constituents and their distances from Earth. We attempt to measure fundamental parameters
Anthony Bak, Vincent Bouchard, Ron Donagi
We study the existence of realistic heterotic vacua on a new Abelian surface fibered Calabi-Yau threefold X with Z_8 x Z_8 fundamental group. Our main result is a no-go theorem, which says that (under mild assumptions) there is no stable holomorphic vector bundle on X satisfying the constraints required by global consistency of the heterotic vacuum and pheno
C. P. Burgess, J. M. Cline, M. Postma
We study the motion of a D3 brane moving within a Type IIB string vacuum compactified to 4D on K3 x T_2/Z_2 in the presence of D7 and O7 planes. We work within the effective 4D supergravity describing how the mobile D3 interacts with the lightest bulk moduli of the compactification, including the effects of modulus-stabilizing fluxes. We seek inflationary so
Adam J. Tenenbaum, Raviraj S. Adve
We consider linear precoding and decoding in the downlink of a multiuser multiple-input, multiple-output (MIMO) system, wherein each user may receive more than one data stream. We propose several mean squared error (MSE) based criteria for joint transmit-receive optimization and establish a series of relationships linking these criteria to the signal-to-inte
Lahcen Assoud, Florian Ebert, Peter Keim, René Messina
An ultra-fast quench is applied to binary mixtures of superparamagnetic colloidal particles confined at a two-dimensional water-air interface by a sudden increase of an external magnetic field. This quench realizes a virtually instantaneous cooling which is impossible in molecular systems. Using real-space experiments, the relaxation behavior after the quenc
Benjamin Jourdain, Jérôme Lelong
Adaptive Monte Carlo methods are very efficient techniques designed to tune simulation estimators on-line. In this work, we present an alternative to stochastic approximation to tune the optimal change of measure in the context of importance sampling for normal random vectors. Unlike stochastic approximation, which requires very fine tuning in practice, we p
Marek Szydlowski, Orest Hrycyna
In this letter we apply dynamical system methods to study all evolutional paths admissible for all initial conditions of the FRW cosmological model with a non-minimally coupled to gravity scalar field and a barotropic fluid. We choose "energy variables" as phase variables. We reduce dynamics to a 3-dimensional dynamical system for an arbitrary potent
S. P. Tsarev, E. Shemyakova
Here, Darboux's classical results about transformations with differential substitutions for hyperbolic equations are extended to the case of parabolic equations of the form $L u = \big(D^2_{x} + a(x,y) D_x + b(x,y) D_y + c(x,y)\big)u=0$. We prove a general Theorem that provides a way to determine transformations for parabolic equations shown above. It tu
Theo Buehler
We survey the basics of homological algebra in exact categories in the sense of Quillen. All diagram lemmas are proved directly from the axioms, notably the five lemma, the 3 x 3-lemma and the snake lemma. We briefly discuss exact functors, idempotent completion and weak idempotent completeness. We then show that it is possible to construct the derived categ
R. A. Dawe Martins
We construct a noncommutative geometry with generalised `tangent bundle' from Fell bundle $C^*$-categories ($E$) beginning by replacing pair groupoid objects (points) with objects in $E$. This provides a categorification of a certain class of real spectral triples where the Dirac operator is constructed from morphisms in a category. Applications for phys
Gilles G. de Castro
We review Kajiwara and Watatani's construction of a C*-algebra from an iterated function system (IFS). If the IFS satisfies the finite branch condition or the open set condition, we build an injective homomorphism from Kajiwara-Watatani algebras to the Cuntz algebra, which can be thought as the algebra of the lifted system, and we give the description of its
C. H. Yeung, Y. -C. Zhang
We present a simple introduction to the basic Minority Game (MG) introduced by Challet and Zhang in 1997 and discuss some of its physical properties and subsequent developments. We also introduce some of its variants include the Evolutionay Minority Game (EMG), the Thermal Minority Game (TMG), the simple Minority Game without information and the Grand-canoni
Brian Smyth, Giuseppe Tinaglia
In classical surface theory there are but few known examples of surfaces admitting nontrivial isometric deformations and fewer still non-simply-connected ones. We consider the isometric deformability question for an immersion x: M \to R^3 of an oriented non-simply-connected surface with constant mean curvature H. We prove that the space of all isometric imme
David D. K. Chow
We investigate Killing tensors for various black hole solutions of supergravity theories. Rotating black holes of an ungauged theory, toroidally compactified heterotic supergravity, with NUT parameters and two U(1) gauge fields are constructed. If both charges are set equal, then the solutions simplify, and then there are concise expressions for rank-2 confo
Larry Kirby
The molecular cloud, DR21 Main, is an example of a large-scale gravitational collapse about an axis near the plane of the sky where the collapse is free of major disturbances due to rotation or other effects. Using flux maps, polarimetric maps, and measurements of the field inclination by comparing the line widths of ion and neutral species, we estimate the
Serguei Komissarov, Nektarios Vlahakis, Arieh Konigl, Maxim Barkov
We present a relativistic-MHD numerical study of axisymmetric, magnetically driven jets with parameters applicable to gamma-ray burst (GRB) flows. We also present analytic expressions for the asymptotic jet shape and other flow parameters that agree very well with the numerical results. All current-carrying outflows exhibit self-collimation and consequent ac