June 2009 arXiv papers — page 44
Showing 4,301–4,400 of 5,471 papers
Juhua Chen, Yongjiu Wang
In this paper using the third-order WKB approximation, a numerical method devised by Schutz, Will and Iyer, we investigate the quasinormal frequencies of the scalar field in the background of five-dimensional Lovelock black hole. We find that the ultraviolet correction to Einstein theory in the Lovelock theory makes the scalar field decay more slowly and mak
Werner M. Sun
Using e+e- collision data in the sqrt{s} = 4 GeV energy region, CLEO-c has made extensive studies of semileptonic and leptonic decays of the D0, D+, and Ds+ charmed mesons. We report recent measurements of absolute branching fractions, form factors, and decay constants that serve as precision tests of theoretical calculations.
Marc Manera, Ravi K Sheth, Roman Scoccimarro
The peak-background split argument is commonly used to relate the abundance of dark matter halos to their spatial clustering. Testing this argument requires an accurate determination of the halo mass function. We present a Maximum Likelihood method for fitting parametric functional forms to halo abundances which differs from previous work because it does not
Michael Krivelevich, Choongbum Lee, Benny Sudakov
A graph $G$ on $n$ vertices is \textit{pancyclic} if it contains cycles of length $t$ for all $3 \leq t \leq n$. In this paper we prove that for any fixed $ε>0$, the random graph $G(n,p)$ with $p(n)\gg n^{-1/2}$ asymptotically almost surely has the following resilience property. If $H$ is a subgraph of $G$ with maximum degree at most $(1/2 - ε)np$ then $G-H$
Phase boundary and finite temperature crossovers of the quantum Ising model in two dimensions
cond-mat.stat-mechP. Strack, P. Jakubczyk
We revisit the two-dimensional quantum Ising model by computing renormalization group flows close to its quantum critical point. The low but finite temperature regime in the vicinity of the quantum critical point is squashed between two distinct non-Gaussian fixed points: the classical fixed point dominated by thermal fluctuations and the quantum critical fi
Adam Rycerz, Patrik Recher, Michael Wimmer
Ballistic transport through a collection of quantum billiards in undoped graphene is studied analytically within the conformal mapping technique. The billiards show pseudodiffusive behavior, with the conductance equal to that of a classical conductor characterized by the conductivity $σ_0=4e^2/πh$, and the Fano factor $F=1/3$. By shrinking at least one of th
K. Maltman, C. E. Wolfe, S. Banerjee, I. M. Nugent
We update the hadronic tau determination of |V_{us}|, showing that current strange branching fractions produce results 2-3 sigma lower than 3-family unitarity expectations. Issues related to the size of theoretical uncertainties and results from an alternate, mixed tau-electroproduction sum rule determination (which, by construction, produces a much smaller
The dynamics of unforced turbulence at high Reynolds number for Taylor-Green vortices generalized to MHD
physics.flu-dynA. Pouquet, E. Lee, M. E. Brachet, P. D. Mininni
We study decaying magnetohydrodynamics (MHD) turbulence stemming from the evolution of the Taylor-Green (TG) flow generalized recently to MHD, with equal viscosity and magnetic resistivity and up to equivalent grid resolutions of 2048^3 points. A pseudo-spectral code is used in which the symmetries of the velocity and magnetic fields have been implemented, a
Sergio Giudici
High statistics sample of kaon decays collected by NA48-CERN experiment allowed two independent measurements of the pion scattering length. Methods and Results are discussed
G. Palasantzas, V. B. Svetovoy, P. J. van Zwol
In this paper we investigate the influence of ultra thin water layer (1-1.5 nm) on the van der Waals/Casimir force between gold surfaces. Adsorbed water is inevitably present on gold surfaces at ambient conditions as jump-up-to contact during adhesion experiments demonstrate. Calculations based on the Lifshitz theory give very good agreement with the experim
Netanel Blaier
Let M be a bounded open plane domain. Let f be a continuous function on the closure of M, 3-times continuously differentiable in M, which vanish on the boundary. Polterovich and Sodin proved that the values of f cannot exceed the norm of the hessian of f, averaged over the entire domain M. In this paper we study the equality case for this inequality. We show
Shantanu Dave
We consider distributions on a closed compact manifold $M$ as maps on smoothing operators. Thus spaces of certain maps between $Ψ^{-\infty}(M)\to \mathcal{C}^{\infty}(M)$ are considered as generalized functions. For any collection of regularizing processes we produce an algebra of generalized functions and a diffeomorphism equivariant embedding of distributi
M. Cencelj, J. Dydak, A. Vavpeti\v\{c}, \v\{Z}. Virk
Using ideas from shape theory we embed the coarse category of metric spaces into the category of direct sequences of simplicial complexes with bonding maps being simplicial. Two direct sequences of simplicial complexes are equivalent if one of them can be transformed to the other by contiguous factorizations of bonding maps and by taking infinite subsequence
Emanuele Viola
We prove that to store n bits x so that each prefix-sum query Sum(i) := sum_{k < i} x_k can be answered by non-adaptively probing q cells of log n bits, one needs memory > n + n/log^{O(q)} n. Our bound matches a recent upper bound of n + n/log^{Omega(q)} n by Patrascu (FOCS 2008), also non-adaptive. We also obtain a n + n/log^{2^{O(q)}} n lower bound for sto
J. I. Katz
I propose a simple model, based on an analogy to von Neumann artificial viscosity, of turbulent diffusion, heat diffusion and viscosity coefficients for use in modeling subgrid turbulent diffusivity in multi-phase numerical hydrodynamics and, more generally, in subgrid turbulent viscosity and thermal transport. In analogy to the von Neumann artificial viscos
Electron density in the quiet solar coronal transition region from SoHO/SUMER measurements of S VI line radiance and opacity
astro-ph.SRE. Buchlin, J. -C. Vial
Context: The sharp temperature and density gradients in the coronal transition region are a challenge for models and observations. Aims: We set out to get linearly- and quadratically-weighted average electron densities in the region emitting the S VI lines, using the observed opacity and the emission measure of these lines. Methods: We analyze SoHO/SUMER spe
A. Bouda
The solution with respect to the reduced action of the one-dimensional stationary quantum Hamilton-Jacobi equation is well known in the literature. The extension to higher dimensions in the separated variable case was proposed in contradictory formulations. In this paper we provide new insights into the construction of the reduced action. In particular, cont
Mohammad Abdul Wahab
Existing fourteen Bravais/space lattices are found to be inadequate for proper crystallographic representation and some conceptual understandings. The complicacies, confusions and ambiguities encountered in the representation of trigonal/rhomohedral and hexagonal lattices have been removed by suggesting the need of two more space lattices in the form of Hexa
Hongsheng Zhang, Heng Yu, Zong-Hong Zhu, Yungui Gong
The cosmic coincidence problem is a serious challenge to dark energy model. We suggest a quantitative criteria for judging the severity of the coincidence problem. Applying this criteria to three different interacting models, including the interacting quintessence, interacting phantom, and interacting Chaplygin gas models, we find that the interacting Chaply
Finite thin disc models of four galaxies in the Ursa Major cluster: NGC3877, NGC3917, NGC3949 and NGC4010
astro-ph.GAGuillermo A. González, Sandra M. Plata-Plata, Javier Ramos-Caro
Finite thin disc models of four galaxies in the Ursa Major cluster are presented. The models are obtained by means of the Hunter method and the particular solutions are choosen in such a way that the circular velocities are adjusted very accurately to the observed rotation curves of some specific spiral galaxies. We present particular models for the four gal
Zi-Hua Weng
The paper discusses the affection of the scalar potential on the speed of light in the electromagnetic field, by means of the characteristics of octonion. In the octonion space, the radius vector is combined with the integral of field potentials to become one new radius vector. When the field potentials can not be neglected, the new radius vector will cause
Discovery of Molecular Loop 3 in the Galactic Center: Evidence for a Positive-Velocity Magnetically Floated Loop towards $L=355^\circ-359^\circ$
astro-ph.GAMotosuji Fujishita, Kazufumi Torii, Natsuko Kudo, Tokuichi Kawase
We have discovered a molecular dome-like feature towards $355^{\circ} \leq l \leq 359^{\circ}$ and $0^{\circ} \leq b \leq 2^{\circ}$. The large velocity dispersions of 50--100 km s$^{-1}$ of this feature are much larger than those in the Galactic disk and indicate that the feature is located in the Galactic center, probably within $\sim1$ kpc of Sgr A$^{*}$.
G. J. Conduit, A. G. Green, B. D. Simons
A variety of analytical techniques suggest that quantum fluctuations lead to a fundamental instability of the Fermi liquid that drives ferromagnetic transitions first order at low temperatures. We present both analytical and numerical evidence that, driven by the same quantum fluctuations, this first order transition is pre-empted by the formation of an inho
Ab-initio procedure for effective models of correlated materials with entangled band structure
cond-mat.str-elTakashi Miyake, Ferdi Aryasetiawan, Masatoshi Imada
We present a first-principles method for deriving effective low-energy models of electrons in solids having entangled band structure. The procedure starts with dividing the Hilbert space into two subspaces, the low-energy part ("$d$ space'') and the rest of the space ("$r$ space''). The low-energy model is constructed for the $d$ spac
Efficient Algorithms for Several Constrained Resource Allocation, Management and Discovery Problems
cs.DSMugurel Ionut Andreica, Madalina Ecaterina Andreica, Daniel Ardelean
In this paper we present efficient algorithmic solutions for several constrained resource allocation, management and discovery problems. We consider new types of resource allocation models and constraints, and we present new geometric techniques which are useful when the resources are mapped to points into a multidimensional feature space. We also consider a
Efficient Algorithms for Several Constrained Activity Scheduling Problems in the Time and Space Domains
cs.DSMadalina Ecaterina Andreica, Mugurel Ionut Andreica, Angela Andreica
In this paper we consider several constrained activity scheduling problems in the time and space domains, like finding activity orderings which optimize the values of several objective functions (time scheduling) or finding optimal locations where certain types of activities will take place (space scheduling). We present novel, efficient algorithmic solution
V. D. Orlovsky, V. I. Shevchenko
Connected two-point field strength correlators have been measured on the lattice in quaternionic projective sigma-model of pure SU(2) Yang-Mills theory. The correlation lengths, extracted from the exponential fit for these correlators, are found to be lambda_1^{-1} = 1.40(3) GeV and lambda^{-1} = 1.51(3) GeV in good agreement with other existing calculations
Yonatan Kaspi, Neri Merhav
We consider a broadcast channel with a degraded message set, in which a single transmitter sends a common message to two receivers and a private message to one of the receivers only. The main goal of this work is to find new lower bounds to the error exponents of the strong user, the one that should decode both messages, and of the weak user, that should dec
Vassiliki Kanellopoulos, Manfred Kleber, Tobias Kramer
We present the analytical solution in closed form for the semiclassical limit of the quantum mechanical Coulomb Green function in position space in n dimensions. We utilize a projection method which has its roots in Lambert's theorem and which allows us to treat the system as an essentially one dimensional problem. The semiclassical result assumes a simp
Jian-Song Zhang
We present a scheme to control the entanglement sudden birth and death in cavity quantum electrodynamics system, which consists of two noninteracting atoms each locally interacting with its own vacuum field, by applying and adjusting classical driving fields.
Malay Bandyopadhyay
The effect of an externally applied high frequency oscillating electric field on the critical nucleation field of superconductivity in the bulk as well as at the surface of a superconductor is investigated in details in this work. Starting from the linearized time dependent Ginzburg-Landau (TDLG) theory and using the variational principle we have shown the a
Control of the entanglement of a two-level atom in a dissipative cavity via a classical field
quant-phJian-Song Zhang, Jing-Bo Xu
We investigate the entanglement dynamics and purity of a two-level atom, which is additionally driven by a classical field, interacting with a coherent field in a dissipative environment. It is shown that the amount of entanglement and the purity of the system can be improved by controlling the classical field.
Malay Bandyopadhyay
Explicit results for various quantum thermodynamic function (QTF) of a charged magneto-oscillator coupled to a heat bath at arbitrary temperature are demonstrated in this paper. Discernible expressions for different QTF in the two limits of very low and very high temperatures are presented for three popular heat bath models : Ohmic, single relaxation time an
Motion by anisotropic mean curvature as sharp interface limit of an inhomogeneous and anisotropic Allen-Cahn equation
math.APMatthieu Alfaro, Harald Garcke, Danielle Hilhorst, Hiroshi Matano
We study the singular limit of a spatially inhomogeneous and anisotropic reaction-diffusion equation. We use a Finsler metric related to the anisotropic diffusion term and work in relative geometry. We prove a weak comparison principle and perform an analysis of both the generation and the motion of interfaces. The limit problem involves motion by anisotropi
Matthieu Alfaro
We investigate the behavior, as a small parameter tends to zero, of a nonlocal Allen-Cahn equation. Given a rather general initial data, we perform a rigorous analysis of both the generation and the motion of interface, and obtain a new estimate for its thickness. The limit problem involves motion by mean curvature together with a nonlocal effect (which allo
The Heated Laminar Vertical Jet in a Liquid with Power-law Temperature Dependence of Density
physics.flu-dynV. A. Sharifulin
The analytical solution of heated laminar vertical jet in a liquid with power-law temperature dependence of density was obtained in the skin-layer approximation for certain values of Prandtl number. Cases of point and linear sources were considered.
Wei Zhou, Jianfeng Zhan, Dan Meng
It is effective to improve the reliability and availability of large-scale cluster systems through the analysis of failures. Existed failure analysis methods understand and analyze failures from one or few dimension. The analysis results are partial and with less precision because of the limitation of data source. This paper presents multidimensional analysi
Xu Liu, Jianfeng Zhan, Bibo Tu, Ming Zou
Different from sequential programs, parallel programs possess their own characteristics which are difficult to analyze in the multi-process or multi-thread environment. This paper presents an innovative method to automatically analyze the SPMD programs. Firstly, with the help of clustering method focusing on similarity analysis, an algorithm is designed to l
On astrophysical explanations due to cosmological inhomogeneities for the observational acceleration
astro-ph.COKenji Tomita
We review various cosmological models with a local underdense region (local void) and the averaged models with the backreaction of inhomogeneities, which have been proposed to explain (without assuming a positive cosmological constant) the observed accelerating behaviors appearing in the magnitude-redshift relation of SNIa. To clarify their reality, we consi
Yang Li, Zhao-Ming Gan, Ding-Xiong Wang
We propose a simplified model of outflow/jet driven by the Blandford-Payne (BP) process from advection dominated accretion flows (ADAF) and derive the expressions of the BP power and disk luminosity based on the conservation laws of mass, angular momentum and energy. We fit the 2--10 keV luminosity and kinetic power of 15 active galactic nucleus (AGNs) of su
Lin Lin, Jianfeng Lu, Lexing Ying, E Weinan
Two approaches for the efficient rational approximation of the Fermi-Dirac function are discussed: one uses the contour integral representation and conformal mapping and the other is based on a version of the multipole representation of the Fermi-Dirac function that uses only simple poles. Both representations have logarithmic computational complexity. They
David Callan
We survey combinatorial interpretations of some dozen identities for the double factorial such as, for instance, (2n-2)!! + Sum_{k=2}^{n} (2n-1)!!(2k-4)!!/(2k-1)!! = (2n-1)!!. Our methods are mostly bijective.
Dachun Yang, Dongyong Yang
Let $μ$ be a non-negative Radon measure on ${\mathbb R}^d$ which only satisfies the polynomial growth condition. Let ${\mathcal Y}$ be a Banach space and $H^1(μ)$ the Hardy space of Tolsa. In this paper, the authors prove that a linear operator $T$ is bounded from $H^1(μ)$ to ${\mathcal Y}$ if and only if $T$ maps all $(p, γ)$-atomic blocks into uniformly bo
Mohamed Kaddar
Let $X$ and $S$ be complex spaces with $X$ countable at infinity and $S$ reduced locally pure dimensional. Let $π:X\to S$ be an universally-$n$-equidimensional morphism (i.e open with constant pure $n$-dimensional fibers). If there is a cycle $\goth{X}$ of $X\times S$ such that, his support coincide fiberwise set-theorically with the fibers of $π$ and endowe
Peter Maurer, Nicolas Delerue, David Urner, George Doucas
To measure the energy spread of a energy electron beam up to $5 GeV$ in a single shoot measurement the possible applications of an existing magnet as spectrometer has been discussed. For distinguishing the energy resolution and an optimal experimental setup numerical simulation, based on the measured magnetic field, have been performed.
Guang Cheng, Jianhua Z. Huang
Consider $M$-estimation in a semiparametric model that is characterized by a Euclidean parameter of interest and an infinite-dimensional nuisance parameter. As a general purpose approach to statistical inferences, the bootstrap has found wide applications in semiparametric $M$-estimation and, because of its simplicity, provides an attractive alternative to t
Jack L. Ritchie
We review recent results from the BABAR and Belle experiments on rare electroweak B-meson decays, with emphasis on those occurring through flavor changing neutral current interactions of the type b -> s l l. The recent results include measurements of the isospin asymmetry and lepton forward-backward asymmetry in B -> K* l+ l- decays from BABAR, a search for
Nonadditivity of quantum and classical capacities for entanglement breaking multiple-access channels and butterfly network
quant-phAndrzej Grudka, Pawel Horodecki
We analyze quantum network primitives which are entanglement-breaking. We show superadditivity of quantum and classical capacity regions for quantum multiple-access channel and quantum butterfly network. Since the effects are especially visible at high noise they suggest that quantum information effects may be particularly helpful in the case of the networks
Mircea Cimpoeas
We prove that the Stanley's conjecture holds for monomial ideals $I\subset K[x_1,...,x_n]$ generated by at most $2n-1$ monomials, i.e. $sdepth(I)\geq depth(I)$.
Oliver Stelzer-Chilton
We present results from electroweak precision measurements at CDF. These include the measurement of the Z boson rapidity distribution using di-electron events, the W boson charge asymmetry measurement in the electron-neutrino decay and the direct measurement of the W boson mass and width in both the electron-neutrino and muon-neutrino decay channels.
F. E. S. Steinhoff, M. C. de Oliveira
We construct a family of bipartite states of arbitrary dimension whose eigenvalues of the partially transposed matrix can be inferred directly from the block structure of the global density matrix. We identify from this several subfamilies in which the PPT criterion is both necessary and sufficient. A sufficient criterion of separability is obtained, which i
Stefan Boettcher
The scaling of fluctuations in the distribution of ground-state energies or costs with the system size N for Ising spin glasses is considered using an extensive set of simulations with the Extremal Optimization heuristic across a range of different models on sparse and dense graphs. These models exhibit very diverse behaviors, and an asymptotic extrapolation
A. V. Nefediev, J. E. F. T. Ribeiro
Generalised Nambu-Jona-Lasinio model for QCD is considered at finite temperatures in the framework of a real-time formalism. The proposed approach allows one to study various properties of the model at T>0, such as chiral symmetry breaking and restoration, properties of the bound-state spectrum, and so on.
Jan Stovicek
Given an abelian category, we characterize the long exact sequences of length six which can be obtained from the snake lemma. Equivalently, these are the long exact sequences which arise as the homology of a triangle in the corresponding derived bounded category.
Matteo Luca Ruggiero, Lorenzo Iorio
We study the effects of a time-varying gravitomagnetic field on the motion of test particles. Starting from recent results, we consider the gravitomagnetic field of a source whose spin angular momentum has a linearly time-varying magnitude. The acceleration due to such a time-varying gravitomagnetic field is considered as a perturbation of the Newtonian moti
P. Abbamonte, G. C. L. Wong, D. Cahill, J. P. Reed
We describe a new method for imaging ultrafast dynamics in condensed matter using inelastic x-ray scattering (IXS). We use the concepts of causality and irreversibility to construct a general solution to the inverse scattering problem (or "phase problem") for inelastic x-ray scattering, which enables direct imaging of dynamics of the electron density
Linda M. Carpenter, Michael Dine, Guido Festuccia
Invoking the Peccei-Quinn (PQ) solution to the strong CP problem substitutes the puzzle of why $\theta_{qcd}$ is so small with the puzzle of why the PQ symmetry is of such high quality. Cosmological and astrophysical considerations raise further puzzles. This paper explores this issues in several contexts: string theory and field theory, and theories without
Askar Dzhumadil'daev, Pasha Zusmanovich
Using computer calculations, we prove the statement in the title.
Francesco D'Andrea, Pierre Martinetti
We discuss the relation between the Wasserstein distance of order 1 between probability distributions on a metric space, arising in the study of Monge-Kantorovich transport problem, and the spectral distance of noncommutative geometry. Starting from a remark of Rieffel on compact manifolds, we first show that on any - i.e. non-necessary compact - complete Ri
Laurentiu Maxim, Joerg Schuermann
We prove very general formulae for the generating series of (Hodge) genera of symmetric products with coefficients, which hold for complex quasi-projective varieties with any kind of singularities, and which include many of the classical results in the literature as special cases. Important specializations of our results include generating series for extensi
A. Alonso Izquierdo, M. A. Gonzalez Leon, J. Mateos Guilarte, M. J. Senosiain
One-loop mass shifts to the classical masses of stable kinks arising in a massive non-linear ${\mathbb S}^2$-sigma model are computed. Ultraviolet divergences are controlled using the heat kernel/zeta function regularization method. A comparison between the results achieved from exact and high-temperature asymptotic heat traces is analyzed in depth.
Vesselin Petkov, Luchezar Stoyanov
In this paper we prove two asymptotic estimates for pairs of closed trajectories for open billiards similar to those established by Pollicott and Sharp for closed geodesics on negatively curved compact surfaces. The first of these estimates holds for general open billiards in any dimension. The more intricate second estimate is established for open billiards
Kyosuke Hotta, Yoshifumi Hyakutake, Takahiro Kubota, Takahiro Nishinaka
We consider the holographic renormalization group (RG) flow in three dimensional gravity with the gravitational Chern-Simons term coupled to some scalar fields. We apply the canonical approach to this higher derivative case and employ the Hamilton-Jacobi formalism to analyze the flow equations of two dimensional field theory. Especially we obtain flow equati
Chonghui Huang, Zhaoyong Huang
Let $R$ be a left and right Noetherian ring. We introduce the notion of the torsionfree dimension of finitely generated $R$-modules. For any $n\geq 0$, we prove that $R$ is a Gorenstein ring with self-injective dimension at most $n$ if and only if every finitely generated left $R$-module and every finitely generated right $R$-module have torsionfree dimensio
Joseph Ben Geloun, John R. Klauder
The notion of ladder operators is introduced for systems with continuous spectra. We identify two different kinds of annihilation operators allowing the definition of coherent states as modified "eigenvectors" of these operators. Axioms of Gazeau-Klauder are maintained throughout the construction.
Fu-Gao Song, Francis Austin
This paper views the honeycomb conjecture and the Kepler problem essentially as extreme value problems and solves them by partitioning 2-space and 3-space into building blocks and determining those blocks that have the universal extreme values that one needs. More precisely, we proved two results. First, we proved that the regular hexagons are the only 2-dim
Pietro Caputo, Thomas M. Liggett, Thomas Richthammer
Aldous' spectral gap conjecture asserts that on any graph the random walk process and the random transposition (or interchange) process have the same spectral gap. We prove the conjecture using a recursive strategy. The approach is a natural extension of the method already used to prove the validity of the conjecture on trees. The novelty is an idea base
A. Ataç, A. Kaşkaş, S. Akkoyun, M. Şenyiğit
Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simul
Alexei Iantchenko, Evgeny Korotyaev
We consider the zigzag half-nanotubes (tight-binding approximation) in a uniform magnetic field which is described by the magnetic Schrödinger operator with a periodic potential plus a finitely supported perturbation. We describe all eigenvalues and resonances of this operator, and theirs dependence on the magnetic field. The proof is reduced to the analysis
Farzad Didehvar
Could we define I? Throughout this article we give a negative answer to this question. More exactly, we show that there is no definition for I in a certain way. But this negative answer depends on our definition of definability. Here, we try to consider sufficient generalized definition of definability. In the middle of paper a paradox will arise which makes
Andrew Strominger
We present five open problems in quantum gravity which one might reasonably hope to solve in the next decade. Hints appearing in the literature are summarized for each one.
I. Bejenaru, A. D. Ionescu, C. E. Kenig
We prove large-data local stability theorems for several spin models in two dimensions.
Michael Engelhardt
The random vortex world-surface model is an infrared effective model of Yang-Mills dynamics based on center vortex degrees of freedom. These degrees of freedom carry topological charge through writhe and self-intersection of their world-surfaces. A practical implementation of the model realizes the vortex world-surfaces by composing them of elementary square
O. Sotolongo-Grau, D. Rodriguez-Perez, J. A. Santos-Miranda, M. M. Desco
It is possible to find the optimized radiation dose per session for a radiotherapy (RT) treatment, using a population dynamics model. This has already been done in a previous work for a protocol with 30 sessions and a fixed dose per session. Extending this model to other protocols, with a variable number of sessions, we could change the radiation dosage whil
A. Olariu, P. Mendels, F. Bert, L. K. Alexander
We report a muSR study of LiCrO2, which has a magnetic lattice made up of a stacking of triangular Heisenberg antiferromagnetic (Cr3+, S = 3/2) layers. A static magnetically ordered state is observed below the transition temperature T_N = 62 K, while the expected peak of the relaxation rate is slightly shifted downward by a few kelvins below T_N. We draw a c
Hiroshi Iritani
We study possible real structures in the space of solutions to the quantum differential equation. We show that, under mild conditions, a real structure in orbifold quantum cohomology yields a pure and polarized tt^*-geometry near the large radius limit. We compute an example of P^1 which is pure and polarized over the whole Kaehler moduli space H^2(P^1,C^*).
W. J. Venstra, H. S. J. van der Zant
We present a method for efficient spectral readout of mechanical resonator arrays in dissipative environments. Magnetomotive drive and detection is used to drive double clamped resonators in the nonlinear regime. Resonators with almost identical resonance frequencies can be tracked individually by sweeping the drive power. Measurements are performed at room
Design considerations for the Micro Vertex Detector of the Compressed Baryonic Matter experiment
nucl-exM. Deveaux, S. Amar-Youcef, C. Dritsa, I. Froehlich
The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase diagram in the region of moderate temperatures and highest net-baryon densities in search of the first-order phase transition from confined to deconfined matter at the QCD cr
Memory and aging effects in interacting sub-10nm nanomagnets with large uniaxial anisotropy
cond-mat.mtrl-sciKai-Cheng Zhang, Bang-Gui Liu
Using a nonequilibrium Monte Carlo method suitable to nanomagnetism, we investigate representative systems of interacting sub-10nm grained nanomagnets with large uniaxial anisotropy. Various magnetization memory and aging effects are found in such systems. We explain these dynamical effects using the distributed relaxation times of the interacting nanomagnet
Mohamed Kaddar
This second part is devoted to the proof of all main results that we have mentionned in [KI].
Stable two-dimensional ferromagnets made of regular single-layered lattices of single-molecule nanomagnets on substrates
cond-mat.mtrl-sciRui Zheng, Bang-Gui Liu
We propose that stable two-dimensional (2D) ferromagnets can be made of regular single-layered lattices of single-molecule nanomagnets with enough uniaxial magnetic anisotropy on appropriate substrates by controlling the inter-nanomagnet magnetic interaction. Our Monte Carlo simulated results show that such ideal 2D ferromagnets are thermodynamically stable
Josip Globevnik
Let U be the closed unit disc in C and let p be a point on the unit circle. Let f be a continuous function on U which extends holomorphically from each circle contained in U and centered at the origin, and from each circle contained in U and passing through the point p. Then f is holomorphic in the interior of U.
Michael Engelhardt
The topological charge is constructed for SU(3) center vortex world-surfaces composed of elementary squares on a hypercubic lattice. In distinction to the SU(2) case investigated previously, it is necessary to devise a proper treatment of the color structure at vortex branchings, which arise in the SU(3) case, but not for SU(2). The construction is used to e
Pavel Machalek, Peter R. McCullough, Adam Burrows, Christopher J. Burke
We estimate flux ratios of the extrasolar planet XO-2b to its host star XO-2 at 3.6, 4.5, 5.8 and 8.0 micron with IRAC on the Spitzer Space Telescope to be 0.00081 +- 0.00017, 0.00098 +- 0.00020, 0.00167 +- 0.00036 and 0.00133 +- 0.00049, respectively. The fluxes provide tentative evidence for a weak temperature inversion in the upper atmosphere, the precise
Carl M. Bender, Karim Besseghir, Hugh F. Jones, Xinghui Yin
The energy eigenvalues of the class of non-Hermitian PT-symmetric Hamiltonians $H=p^2+x^2(ix)^ε$ ($ε\geq0$) are real, positive, and discrete. The behavior of these eigenvalues has been studied perturbatively for small $ε$. However, until now no other features of $H$ have been examined perturbatively. In this paper the small-$ε$ expansion of the C operator an
R. D. Simitev, F. H. Busse
Patterns of convection in internally heated, self-gravitating rotating spherical fluid shells are investigated through numerical simulations. While turbulent states are of primary interest in planetary and stellar applications the present paper emphasizes more regular dynamical features at Rayleigh numbers not far above threshold which are similar to those w
Peng-Zhi Huang, Liang Zhang, Shi-Lin Zhu
We calculate the coupling constants between the light vector mesons and heavy mesons within the framework of the light-cone QCD sum rule in the leading order of heavy quark effective theory. The sum rules are very stable with the variations of the Borel parameter and the continuum threshold. The extracted couplings will be useful in the study of the possible
P. Desesquelles, T. M. H. Ha, A. Korichi, F. Le Blanc
A new method for the determination of electric signal time-shifts is introduced. As the Kolmogorov-Smirnov test, it is based on the comparison of the cumulative distribution functions of the reference signal with the test signal. This method is very fast and thus well suited for on-line applications. It is robust to noise and its performances in terms of pre
Denys I. Bondar, Wing-Ki Liu, Gennady L. Yudin
Savichev's modified adiabatic approximation [Sov. Phys. JETP 73, 803 (1991)] is used to obtain a general form of a quantum-mechanical amplitude of ionization by a low-frequency laser field. The method possesses only one requirement that the frequency of the laser field must be low. Connections of the obtained result with the quasi-classical approximation
Comparison of charged-defect finite-size supercell correction methods in a general framework
cond-mat.mes-hallHannu-Pekka Komsa, Tapio T. Rantala
Starting from the total energy expressions within density functional theory, we are able to perform a comparison of several currently used charged-defect finite-size supercell correction schemes in a unified manner. This approach also provides a framework for a further development of corrections not only for DFT supercell calculations, but also for more adva
Matrix formalism and singular-value decomposition for the location of gamma interactions in segmented HPGe detectors
physics.data-anP. Desesquelles, T. M. H. Ha, K. Hauschild, A. Korichi
Modern coaxial and planar HPGe detectors allow a precise determination of the energies and trajectories of the impinging gamma-rays. This entails the location of the gamma interactions inside the crystal from the shape of the delivered signals. This paper reviews the state of the art of the analysis of the HPGe response function and proposes methods that lea
Devendraa Siingh, V. Gopalakrishnan, R. P. Singh, A. K. Kamra
Research work in the area of the Global Electric Circuit (GEC) has rapidly expanded in recent years mainly through observations of lightning from satellites and ground-based networks and observations of optical emissions between cloud and the ionosphere. After reviewing this progress, we critically examine the role of various generators of the currents flowi
Michael T. Lederer, Thomas Lebzelter, Sergio Cristallo, Oscar Straniero
Low-mass stars are element factories that efficiently release their products in the final stages of their evolution by means of stellar winds. Since they are large in number, they contribute significantly to the cosmic matter cycle. To assess this contribution quantitatively, it is crucial to obtain a detailed picture of the stellar interior, particularly wi
Low Temperature Crystal Structures and Magnetic Properties of the V4-Cluster Compounds Ga1-xGexV4S8
cond-mat.str-elDaniel Bichler, Herta Slavik, Dirk Johrendt
The solid solution Ga1-xGexV4S8 (x = 0 - 1) was synthesized by solid state reactions and characterized by temperature-dependent x-ray powder diffraction and static magnetic susceptibility measurements. The compounds crystallize in the cubic GaMo4S8-type structure (space group F-43m), built up by heterocubane-like [V4S4](5-x)+ cubes and [Ga1-xGexS4](5-x)- tet
Gui-Qiang Chen, Mikhail Feldman
When a plane shock hits a wedge head on, it experiences a reflection-diffraction process, and then a self-similar reflected shock moves outward as the original shock moves forward in time. The complexity of reflection-diffraction configurations was first reported by Ernst Mach in 1878, and experimental, computational, and asymptotic analysis has shown that v
Giant Modal Gain, Amplified Surface Plasmon Polariton Propagation, and Slowing Down of Energy Velocity in a Metal-Semiconductor-Metal Structure
physics.opticsD. B. Li, C. Z. Ning
We investigated surface plasmon polariton (SPP) propagation in a metal-semiconductor-metal structure where semiconductor is highly excited to have optical gain. We show that near the SPP resonance, the imaginary part of the propagation wavevector changes from positive to hugely negative, corresponding to an amplified SPP propagation. The SPP experiences a gi
Shuai Dong, Rong Yu, Seiji Yunoki, J. -M. Liu
In this proceeding, recent theoretical investigations by the authors on the multiferroic $R$MnO$_3$ perovskites are briefly reviewed at first. Using the double-exchange model, the realistic spiral spin order in undoped manganites such as TbMnO$_3$ and DyMnO$_3$ is well reproduced by incorporating a weak next-nearest neighbor superexchange ($\sim10%$ of neare
L. G. Balazs, I. Horvath, Zs. Bagoly, A. Meszaros
In a systematic search of the OTs at GRBs the Swift satellite determined only an upper limit of the apparent brightness in a significant fraction of cases. Combining these upper limits with the really measured OT brightness we obtained a sample well suited to survival analysis. Performing a Kaplan-Meier product limit estimation we obtained an unbiased cumula
Michael Mayer
In 1948, W. Hoeffding introduced a large class of unbiased estimators called U-statistics, defined as the average value of a real-valued m-variate function h calculated at all possible sets of m points from a random sample. In the present paper, we investigate the corresponding robust analogue which we call U-quantile-statistics. We are concerned with the as
David L. Canham, H. -W. Hammer, Roxanne P. Springer
Both the mass (just below the D^{*0}Dbar^0 threshold) and the likely quantum numbers (J^{PC}=1^{++}) of the X(3872) suggest that it is either a weakly-bound hadronic ``molecule'' or a virtual state of charmed mesons. Assuming the X(3872) is a weakly-bound molecule, the scattering of neutral D and D* mesons off the X(3872) can be predicted from the X(