April 2013 arXiv papers — page 54
Showing 5,301–5,400 of 7,616 papers
Arthur Hebecker, Alexander K. Knochel, Timo Weigand
The Higgs quartic coupling has now been indirectly measured at the electroweak scale. Assuming no new low-scale physics, its running is known and, together with gauge and Yukawa couplings, it is a crucial new piece of information constraining UV completions of the Standard Model. In particular, supersymmetry broken at an intermediate or high energy scale wit
Cristiano Nisoli, Alan. R. Bishop
The inverse square potential arises in a variety of different quantum phenomena, yet notoriously it must be handled with care: it suffers from pathologies rooted in the mathematical foundations of quantum mechanics. We show that its recently studied conformality-breaking corresponds to an infinitely smooth winding-unwinding topological transition for the {\i
Gianluca Calcagni, Giuseppe Nardelli
Starting from a classical-mechanics stochastic model encoded in a Langevin equation, we derive the natural diffusion equation associated with three classes of multiscale spacetimes (with weighted, ordinary, and "q-Poincaré" symmetries). As a consistency check, the same result is obtained by inspecting the propagation of a quantum-mechanical particle
Demonstration of Low Emittance in the Cornell Energy Recovery Linac Injector Prototype
physics.acc-phColwyn Gulliford, Adam Bartnik, Ivan Bazarov, Luca Cultrera
We present a detailed study of the six-dimensional phase space of the electron beam produced by the Cornell Energy Recovery Linac Photoinjector, a high-brightness, high repetition rate (1.3 GHz) DC photoemission source designed to drive a hard x-ray energy recovery linac (ERL). A complete simulation model of the injector has been constructed, verified by mea
Connor Mooney
We prove that solutions to the Monge-Ampere inequality $$\det D^2u \geq 1$$ in $\mathbb{R}^n$ are strictly convex away from a singular set of Hausdorff $n-1$ dimensional measure zero. Furthermore, we show this is optimal by constructing solutions to $\det D^2u = 1$ with singular set of Hausdorff dimension as close as we like to $n-1$. As a consequence we obt
Cesar A. C. Sequeira, Diogo M. F. Santos, Biljana Sljukic, Luis Amaral
A brief analysis of the physics and effects of electrolytic gas evolution is presented. Aspects considered include bubble nucleation, growth, and detachment, enhancement of mass and heat transfer, and decrease of apparent electrical conductivity of bubble containing electrolytes. This analysis is mainly oriented to hydrogen/oxygen evolving electrodes.
Brăduţ Apostol, László Tóth
An integer $k$ is called regular (mod $n$) if there exists an integer $x$ such that $k^2x\equiv k$ (mod $n$). This holds true if and only if $k$ possesses a weak order (mod $n$), i.e., there is an integer $m\ge 1$ such that $k^{m+1} \equiv k$ (mod $n$). Let $\varrho(n)$ denote the number of regular integers (mod $n$) in the set $\{1,2,\ldots,n\}$. This is an
Huai-Dong Cao, Chenxu He
Following Cao-Hamilton-Ilmanen, in this paper we study the linear stability of Perelman's $\nu$-entropy on Einstein manifolds with positive Ricci curvature. We observe the equivalence between the linear stability restricted to the transversal traceless symmetric 2-tensors and the stability of Einstein manifolds with respect to the Hilbert action. As a main a
Reductive linear differential algebraic groups and the Galois groups of parameterized linear differential equations
math.RTAndrey Minchenko, Alexey Ovchinnikov, Michael F. Singer
We develop the representation theory for reductive linear differential algebraic groups (LDAGs). In particular, we exhibit an explicit sharp upper bound for orders of derivatives in differential representations of reductive LDAGs, extending existing results, which were obtained for SL(2) in the case of just one derivation. As an application of the above boun
Ground-state phase diagram and critical temperature of two-component Bose gases with Rashba spin-orbit coupling
cond-mat.quant-gasZeng-Qiang Yu
Ground-state phase diagram of two-component Bose gases with Rashba spin-orbit coupling is determined via a variational approach. A phase in which the fully polarized condensate occupies zero momentum is identified. This zero-momentum phase competes with the spin density wave phase when interspecies interaction is stronger than intraspecies interaction, and t
Reconcile the AMS-02 positron fraction and Fermi-LAT/HESS total $e^{\pm}$ spectra by the primary electron spectrum hardening
astro-ph.HEQiang Yuan, Xiao-Jun Bi
The recently reported positron fraction up to $\sim 350$ GeV by AMS-02 seems to have tension with the total electron/positron spectra detected by Fermi and HESS, for either pulsar or dark matter annihilation/decay scenario as the primary positron sources. In this work we will show that the tension will be removed by an adjustment of the primary electron spec
Quantum limit of laser cooling in dispersively- and dissipatively-coupled optomechanical systems
quant-phTalitha Weiss, Andreas Nunnenkamp
Mechanical oscillators can be cooled by coupling them to an optical or microwave cavity. Going beyond the standard quantum noise approach we find an analytic expression for the steady-state phonon number in systems where the position of the mechanical oscillator modulates the cavity frequency as well as the cavity line width. We trace the origin for the quan
Xavier Carvajal, Wladimir Neves
In this paper we study the theory of operators on complex Hilbert spaces, which attain their minimum in the unit sphere. We prove some important results concerning the characterization of the N*, and also AN* operators, see respectively Definition 1.1 and Definition 1.3. The injective property plays an important role in these operators, and shall be establis
A. V. Radyushkin
We discuss building models for nucleon generalized parton distributions (GPDs) H and E that are based on the formalism of double distributions (DDs). We found that the usual "DD+D-term" construction should be amended by an extra term, ξE^1_+(x,ξ) built from the α/βmoment of the DD e(β,α) that generates GPD E(x,ξ). Unlike the D-term, this function has
New Interpretation of the Recent Result of AMS-02 and Multi-component Decaying Dark Matters with non-Abelian Discrete Flavor Symmetry
hep-phYuji Kajiyama, Hiroshi Okada, Takashi Toma
Recently the AMS-02 experiment has released the data of positron fraction with much small statistical error. Because of the small error, it is no longer easy to fit the data with a single dark matter for a fixed diffusion model and dark matter profile. In this paper, we propose a new interpretation of the data that it originates from decay of two dark matter
New Variables for Classical and Quantum Gravity in all Dimensions V. Isolated Horizon Boundary Degrees of Freedom
gr-qcNorbert Bodendorfer, Thomas Thiemann, Andreas Thurn
In this paper, we generalise the treatment of isolated horizons in loop quantum gravity, resulting in a Chern-Simons theory on the boundary in the four-dimensional case, to non-distorted isolated horizons in 2(n+1)-dimensional spacetimes. The key idea is to generalise the four-dimensional isolated horizon boundary condition by using the Euler topological den
Sven Faller, Stefan Gadatsch, Thomas Mannel
Top quark physics at the LHC may open a window to physics beyond the standard model and even lead us to an understanding of the phenomenon "flavour". However, current flavour data is a strong hint that no "new physics" with a generic flavour structure can be expected in the TeV scale. In turn, if there is "new physics" at the TeV scal
Arturo Fernández-Pérez
We prove the existence of normal forms for some local real-analytic Levi-flat hypersurfaces with an isolated line singularity. We also give sufficient conditions for that a Levi-flat hypersurface with a complex line as singularity to be a pullback of a real-analytic curve in C via a holomorphic function.
Aglaia Myropolska
The Andrews-Curtis conjecture asserts that, for a free group $F_n$ of rank $n$ and a free basis $(x_1,...,x_n)$, any normally generating tuple $(y_1,...,y_n)$ is Andrews-Curtis equivalent to $(x_1,...,x_n)$. This equivalence corresponds to the actions of $\operatorname{Aut}F_n$ and of $F_n$ on normally generating $n$-tuples. The equivalence corresponding to
Matty J. Hoban, Joel J. Wallman, Hussain Anwar, Naïri Usher
Measurement-based quantum computation (MBQC) is a model of quantum computation, in which computation proceeds via adaptive single qubit measurements on a multi-qubit quantum state. It is computationally equivalent to the circuit model. Unlike the circuit model, however, its classical analog is little studied. Here we present a classical analog of MBQC whose
Martin J. Körber, Matthias Michler, Arnd Bäcker, Roland Ketzmerick
In open chaotic systems the number of long-lived resonance states obeys a fractal Weyl law, which depends on the fractal dimension of the chaotic saddle. We study the generic case of a mixed phase space with regular and chaotic dynamics. We find a hierarchy of fractal Weyl laws, one for each region of the hierarchical decomposition of the chaotic phase-space
Nikos Karaiskos, André M. Grabinski, Holger Frahm
The small polaron with generic, nondiagonal boundary terms is investigated within the framework of quantum integrability. The fusion hierarchy of the transfer matrices and its truncation for particular values of the anisotropy parameter are both employed, so that the spectral problem is formulated in terms of a TQ equation. The solution of this equation for
Paul W. Y. Lee, Chengbo Li, Igor Zelenko
Measure contraction properties are generalizations of the notion of Ricci curvature lower bounds in Riemannian geometry to more general metric measure spaces. In this paper, we give sufficient conditions for a Sasakian manifold equipped with a natural sub-Riemannian distance to satisfy these properties. Moreover, the sufficient conditions are defined by the
Jonathan M. Edge, Jian Li, Pierre Delplace, Markus Büttiker
We investigate the current noise correlations at a quantum point contact in a quantum spin Hall structure, focusing on the effect of a weak magnetic field in the presence of disorder. For the case of two equally biased terminals we discover a robust peak: the noise correlations vanish at $B = 0 $ and are negative for $B\not = 0 $. We find that the character
Alexey Ovchinnikov, Michael Wibmer
We develop a Galois theory for systems of linear difference equations with an action of an endomorphism {\sigma}. This provides a technique to test whether solutions of such systems satisfy {\sigma}-polynomial equations and, if yes, then characterize those. We also show how to apply our work to study isomonodromic difference equations and difference algebrai
Gui-Jun Ding, Ye-Ling Zhou
We present a warped extra dimension model with the custodial symmetry $SU(2)_L\times SU(2)_R\times U(1)_X\times P_{LR}$ based on the flavor symmetry $S_4\times Z_2\times Z'_2$, and the neutrinos are taken to be Dirac particles. At leading order, the democratic lepton mixing is derived exactly, and the high dimensional operators introduce corrections of o
Markus Hofer, Maria Rita Iacò, Robert Tichy
We investigate a parametric extension of the classical s-dimensional Halton sequence, where the bases are special Pisot numbers. In a one- dimensional setting the properties of such sequences have already been in- vestigated by several authors [5, 8, 23, 28]. We use methods from ergodic theory to in order to investigate the distribution behavior of multidime
Pramod N. Achar, Anthony Henderson, Daniel Juteau, Simon Riche
We show that two Weyl group actions on the Springer sheaf with arbitrary coefficients, one defined by Fourier transform and one by restriction, agree up to a twist by the sign character. This generalizes a familiar result from the setting of l-adic cohomology, making it applicable to modular representation theory. We use the Weyl group actions to define a Sp
K. Wang, C. Payette, Y. Dovzhenko, P. W. Deelman
We measure the interdot charge relaxation time T_1 of a single electron trapped in an accumulation mode Si/SiGe double quantum dot. The energy level structure of the charge qubit is determined using photon assisted tunneling, which reveals the presence of a low lying excited state. We systematically measure T_1 as a function of detuning and interdot tunnel c
Elton Pasku
Given a $Γ$-semigroup $S$, we construct a semigroup $Σ$ in such a way that one sided ideals and quasi-ideals of $S$ can be regarded as one sided ideals and quasi-ideals respectively of $Σ$. This correspondence and other properties of $Σ$, allow us to obtain several results for $S$ without having the need to work directly with it, but solely employing well kn
B. Zuckerman, B. Klein, S. Xu, M. Jura
Recently, some hot DA-type white dwarfs have been proposed to plausibly be escaping members of the Hyades. We used hydrogen Balmer lines to measure the radial velocities of seven such stars and confirm that three, and perhaps two others, are/were indeed cluster members and one is not. The other candidate Hyad is strongly magnetic and its membership status re
Juan L. Reutter
Nested regular expressions (NREs) have been proposed as a powerful formalism for querying RDFS graphs, but research in a more general graph database context has been scarce, and static analysis results are currently lacking. In this paper we investigate the problem of containment of NREs, and show that it can be solved in PSPACE, i.e., the same complexity as
Antonio Marco, Maria Ninova, Matthew Ronshaugen, Sam Griffiths-Jones
Genetic linkage may result in the expression of multiple products from a polycistronic transcript, under the control of a single promoter. In animals, protein-coding polycistronic transcripts are rare. However, microRNAs are frequently clustered in the genomes of animals, and these clusters are often transcribed as a single unit. The evolution of microRNA cl
Tao Wang, Xue-Feng Zhang, Sebastian Eggert, Axel Pelster
We study the properties of the Bose-Hubbard model for a quadratic optical superlattice. To this end we generalize a recently established effective potential Landau theory for a single component to the case of multi components and find not only the characteristic incompressible solid phases with fractional filling, but also obtain the underlying quantum phase
Juri Poutanen, Alexander A. Mushtukov, Valery F. Suleimanov, Sergey S. Tsygankov
Cyclotron resonance scattering features observed in the spectra of some X-ray pulsars show significant changes of the line energy with the pulsar luminosity. At high luminosities, these variations are often associated with the onset and growth of the accretion column, which is believed to be the origin of the observed emission and of the cyclotron lines. How
On the components of spaces of curves on the 2-sphere with geodesic curvature in a prescribed interval
math.GTNicolau C. Saldanha, Pedro Zühlke
We obtain simple characterizations of the connected components of the space of closed curves on the 2-sphere whose geodesic curvatures are constrained to lie in an open interval $(κ_1,κ_2)$, in terms of $κ_1$ and $κ_2$. Many results concerning the topology of these spaces are established. In particular, we determine the homeomorphism class of some of these c
Florian Meinert, Manfred J. Mark, Emil Kirilov, Katharina Lauber
We study non-equilibrium dynamics for an ensemble of tilted one-dimensional atomic Bose-Hubbard chains after a sudden quench to the vicinity of the transition point of the Ising paramagnetic to anti-ferromagnetic quantum phase transition. The quench results in coherent oscillations for the orientation of effective Ising spins, detected via oscillations in th
Cheng Liang
In this paper, we prove that if $M_t\subset \mathbb{R}^{n+1}$, $2\leq n\leq 6$, is the $n$-dimensional closed embedded $\mathcal{F}-$stable solution to mean curvature flow with mean curvature of $M_t$ is uniformly bounded on $[0,T)$ for $T<\infty$, then the flow can be smoothly extended over time $T$.
D I Russell, R A Blythe
In finite-size population models, one can derive Fokker-Planck equations to describe the fluctuations of the species numbers about the deterministic behaviour. In the steady state of populations comprising two or more species, it is permissible for a probability current to flow. In such a case, the system does not relax to equilibrium but instead reaches a n
Leo Yu Zhang, Xiaobo Hu, Yuansheng Liu, Kwok-Wo Wong
This paper presents a novel efficient chaotic image encryption scheme, in which the temp-value feedback mechanism is introduced to the permutation and diffusion procedures. Firstly, a simple trick is played to map the plain-image pixels to the initial condition of the Logistic map. Then, a pseudorandom number sequence (PRNS) is obtained from iterating the ma
Thomas Mettler
We derive necessary conditions for a complex projective structure on a complex surface to arise via the Levi-Civita connection of a (pseudo-)K\"ahler metric. Furthermore we show that the (pseudo-)K\"ahler metrics defined on some domain in the projective plane which are compatible with the standard complex projective structure are in one-to-one correspondence
Shingo Saito, Noriko Wakabayashi
The multiple zeta values are multivariate generalizations of the values of the Riemann zeta function at positive integers. The Bowman-Bradley theorem asserts that the multiple zeta values at the sequences obtained by inserting a fixed number of twos between 3,1,...,3,1 add up to a rational multiple of a power of π. We show that an analogous theorem holds in
N. Matagne, Fl. Stancu
A simple procedure within the $1/N_c$ expansion method where all the $N_c$ quarks are treated on the same footing has been found successful in describing mixed symmetric negative parity baryon states belonging to the $[{\bf 70},\ell^-]$ multiplets %with $\ell$ = 1, 2 or 3. of the $N$ = 1 and 3 bands. Presently it is applied to mixed symmetric positive parity
Measurement of CP violation and the B_s^0 meson decay width difference with B_s^0\to J/ψK^+ K^- and B_s^0\to J/ψπ^+π^- decays
hep-exLHCb collaboration, R. Aaij, C. Abellan Beteta, B. Adeva
The time-dependent CP asymmetry in B_s^0\to J/ψK^+K^- decays is measured using $pp$ collision data at \sqrt{s}=7TeV, corresponding to an integrated luminosity of 1.0fb^-1, collected with the LHCb detector. The decay time distribution is characterised by the decay widths Γ_L and Γ_H of the light and heavy mass eigenstates of the B_s^0--\bar{B}_s^0 system and
Dipanjan Dey, Kaushik Bhattacharya, Tapobrata Sarkar
Bertrand space-times (BSTs) are static, spherically symmetric solutions of Einstein's equations, that admit stable, closed orbits. Starting from the fact that to a good approximation, stars in the disc or halo regions of typical galaxies move in such orbits, we propose that, under certain physical assumptions, the dark matter distribution of some low sur
Renaud Coulangeon, Gabriele Nebe
We apply Voronoi's algorithm to compute representatives of the conjugacy classes of maximal finite subgroups of the unit group of a maximal order in some simple $\QQ $-algebra. This may be used to show in small cases that non-conjugate orders have non-isomorphic unit groups.
Scott Dodelson, Michael D. Schneider
Extracting parameter constraints from cosmological observations requires accurate determination of the covariance matrix for use in the likelihood function. We show here that uncertainties in the elements of the covariance matrix propagate directly to increased uncertainties in cosmological parameters. When the covariance matrix is determined by simulations,
Alexandra Carpentier
We develop a test to determine whether a function lying in a fixed $L_2$-Sobolev-type ball of smoothness $t$, and generating a noisy signal, is in fact of a given smoothness $s\geq t$ or not. While it is impossible to construct a uniformly consistent test for this problem on every function of smoothness $t$, it becomes possible if we remove a sufficiently la
Limits on neutral Higgs boson production in the forward region in $pp$ collisions at $\sqrt{s} = 7$ TeV
hep-exLHCb collaboration, R. Aaij, C. Abellan Beteta, B. Adeva
Limits on the cross-section times branching fraction for neutral Higgs bosons, produced in $pp$ collisions at $\sqrt{s} = 7$ TeV, and decaying to two tau leptons with pseudorapidities between 2.0 and 4.5, are presented. The result is based on a dataset, corresponding to an integrated luminosity of 1.0 $\mathrm{fb}^{-1}$, collected with the LHCb detector. Can
Andrei Agrachev
We discuss some challenging open problems in the geometric control theory and sub-Riemannian geometry.
Transverse Single Spin Asymmetry in $e+p^\uparrow \to e+J/ψ+X $ and Transverse Momentum Dependent Evolution of the Sivers Function
hep-phRohini M. Godbole, Anuradha Misra, Asmita Mukherjee, Vaibhav S. Rawoot
We extend our analysis of transverse single spin asymmetry (SSA) in electroproduction of $J/ψ$ to include the effect of the scale evolution of the transverse momentum dependent (TMD) parton distribution functions and gluon Sivers function. We estimate SSA for JLab, HERMES, COMPASS, and eRHIC energies using the color evaporation model of charmonium production
First-order phase transition and anomalous hysteresis of Bose gases in optical lattices
cond-mat.quant-gasDaisuke Yamamoto, Takeshi Ozaki, Carlos A. R. Sá de Melo, Ippei Danshita
We study the first-order quantum phase transitions of Bose gases in optical lattices. A special emphasis is placed on an anomalous hysteresis behavior, in which the phase transition occurs in a unidirectional way and a hysteresis loop does not form. We first revisit the hardcore Bose-Hubbard model with dipole-dipole interactions on a triangular lattice to an
On the Cauchy problem for a generalized Camassa-Holm equation with both quadratic and cubic nonlinearity
math.APXingxing Liu, Zhijun Qiao, Zhaoyang Yin
In this paper, we study the Cauchy problem for a generalized integrable Camassa-Holm equation with both quadratic and cubic nonlinearity. By overcoming the difficulties caused by the complicated mixed nonlinear structure, we firstly establish the local well-posedness result in Besov spaces, and then present a precise blow-up scenario for strong solutions. Fu
Andy Diwen Zhu, Hui Ma, Xiaokui Xiao, Siqiang Luo
Given two locations $s$ and $t$ in a road network, a distance query returns the minimum network distance from $s$ to $t$, while a shortest path query computes the actual route that achieves the minimum distance. These two types of queries find important applications in practice, and a plethora of solutions have been proposed in past few decades. The existing
Piotr Pragacz
We describe the positivity of Thom polynomials of singularities of maps, Lagrangian Thom polynomials and Legendrian Thom polynomials. We show that these positivities come from Schubert calculus.
Hans-Otto Georgii, Tomasz Schreiber, Christoph Thäle
A branching random tessellation (BRT) is a stochastic process that transforms a coarse initial tessellation of $\mathbb{R}^d$ into a finer tessellation by means of random cell divisions in continuous time. This concept generalises the so-called STIT tessellations, for which all cells split up independently of each other. Here, we allow the cells to interact,
Sign-changing stationary solutions and blowup for the nonlinear heat equation in dimension two
math.APFlavio Dickstrein, Filomena Pacella, Berardino Scunzi
Consider the nonlinear heat equation v_t-Δv=|v|^{p-1}v in the unit ball of R^2, with Dirichlet boundary condition. Let u_{p,K} be a radially symmetric, sign-changing stationary solution having a fixed number K of nodal regions. We prove that the solution of the equation with initial value λu_{p,K} blows up in finite time if |λ-1|>0 is sufficiently small and
Kinematics and chemical properties of the Galactic stellar populations. The HARPS FGK dwarfs sample
astro-ph.GAV. Zh. Adibekyan, P. Figueira, N. C. Santos, A. A. Hakobyan
(Abridged) We analyze chemical and kinematical properties of about 850 FGK solar neighborhood long-lived dwarfs observed with the HARPS high-resolution spectrograph. The stars in the sample have logg > 4 dex, 5000 < Teff < 6500 K, and -1.39 < [Fe/H] < 0.55 dex. We apply a purely chemical analysis approach based on the [alpha/Fe] vs. [Fe/H] plot to separate G
Taras Banakh, Iryna Pastukhova
In this paper we detect topological Clifford semigroups which are embeddable into Tychonoff products of topological semilattices and cones over topological groups. Also we detect topological Clifford semigroups which embed into compact topological Clifford semigroups.
Bart de Keijzer, Krzysztof R. Apt
We prove two complexity results about the H-index concerned with the Google scholar merge operation on one's scientific articles. The results show that, although it is hard to merge one's articles in an optimal way, it is easy to merge them in such a way that one's H-index increases. This suggests the need for an alternative scientific performanc
Dongmei Liu, Yong Zhang, Jianming Wen, Zhenhua Chen
We report a simple, novel sub-diffraction method, i.e. diffraction interference induced super-focusing in second-harmonic (SH) Talbot effect, to achieve focusing size of less than λ_pump/8 without involving evanescent waves or sub-wavelength apertures. By tailoring point spread functions with Fresnel diffraction interference, we observe periodic SH sub-diffr
Mariusz Adamski, Janusz Jedrzejewski, Taras Krokhmalskii
We study scaling of the ground-state fidelity in neighborhoods of quantum critical points in a model of interacting spinfull fermions - a BCS-like model. Due to the exact diagonalizability of the model, in one and higher dimensions, scaling of the ground-state fidelity can be analyzed numerically with great accuracy, not only for small systems but also for m
Emilio Leonardi
This report considers a fairly general model of constrained queuing networks that allows us to represent both MMBP (Markov Modulated Bernoulli Processes) arrivals and time-varying service constraints. We derive a set of sufficient conditions for throughput optimality of scheduling policies that encompass and generalize all the previously obtained results in
Sebastian Böser, Marek Kowalski, Lukas Schulte, Nora Linn Strotjohann
Building on the technological success of the IceCube neutrino telescope, we outline a prospective low-energy extension that utilizes the clear ice of the South Pole. Aiming at a 10 Mton effective volume and a 10 MeV threshold, the detector would provide sufficient sensitivity to detect neutrino bursts from core-collapse supernovae (SNe) in nearby galaxies. T
Felix P. Hargreaves, Daniel Merkle
We present FooPar, an extension for highly efficient Parallel Computing in the multi-paradigm programming language Scala. Scala offers concise and clean syntax and integrates functional programming features. Our framework FooPar combines these features with parallel computing techniques. FooPar is designed modular and supports easy access to different commun
Jérémy Blanc, Immanuel Stampfli
We study the group of automorphisms of the affine plane preserving some given curve, over any field. The group is proven to be algebraic, except in the case where the curve is a bunch of parallel lines. Moreover, a classification of the groups of positive dimension occuring is also given in the case where the curve is geometrically irreducible and the field
Yan-Lin Tang, Hua-Lei Yin, Xiongfeng Ma, Chi-Hang Fred Fung
Quantum key distribution (QKD) utilizes the laws of quantum mechanics to achieve information-theoretically secure key generation. This field is now approaching the stage of commercialization, but many practical QKD systems still suffer from security loopholes due to imperfect devices. In fact, practical attacks have successfully been demonstrated. Fortunatel
Boris Arm
We study the noncommutative geometry of the dihedral group D 6 using the tools of quantum group theory. We explicit the torsion free regular spin connection and the corresponding 'Levi-Civita' connection. Next, we nd the Riemann curvature and its Ricci tensor. The main result is the Dirac operator of a representation of the group which we nd the eige
Gilles Pagès, Abass Sagna
We propose a new approach to quantize the marginals of the discrete Euler diffusion process. The method is built recursively and involves the conditional distribution of the marginals of the discrete Euler process. Analytically, the method raises several questions like the analysis of the induced quadratic quantization error between the marginals of the Eule
Pablo Fleurquin, José J. Ramasco, Victor M. Eguíluz
Complex networks provide a suitable framework to characterize air traffic. Previous works described the world air transport network as a graph where direct flights are edges and commercial airports are vertices. In this work, we focus instead on the properties of flight delays in the US air transportation network. We analyze flight performance data in 2010 a
Morgan W. Mitchell, Federica A. Beduini
We apply spin-squeezing techniques to identify and quantify highly multi-partite photonic entanglement in polarization-squeezed light. We consider a practical single-mode scenario, and find that Wineland-criterion polarization squeezing implies entanglement of a macroscopic fraction of the total photons. A Glauber-theory computation of the observable N-photo
Chen Feng, Roberto W. Nóbrega, Frank R. Kschischang, Danilo Silva
Though network coding is traditionally performed over finite fields, recent work on nested-lattice-based network coding suggests that, by allowing network coding over certain finite rings, more efficient physical-layer network coding schemes can be constructed. This paper considers the problem of communication over a finite-ring matrix channel $Y = AX + BE$,
Leovigildo Alonso, Ana Jeremias, Marta Perez, Maria J. Vale
A geometric stack is a quasi-compact and semi-separated algebraic stack. We prove that the quasi-coherent sheaves on the small flat topology, Cartesian presheaves on the underlying category, and comodules over a Hopf algebroid associated to a presentation of a geometric stack are equivalent categories. As a consequence, we show that the category of quasi-coh
Sergei Fedotov
In this article we address the problem of the nonlinear interaction of subdiffusive particles. We introduce the random walk model in which statistical characteristics of a random walker such as escape rate and jump distribution depend on the mean field density of particles. We derive a set of nonlinear subdiffusive fractional master equations and consider th
Andrey G. Tlatov
This paper considers the changes of average number of sunspots groups per day, aggregated by activity cycles Gn within the period since 1610 till present time. The relation of parameter Gn of the preceding and the following activity cycles has a long-term variation with the period of about 20 activity cycles. There is a positive correlation between the param
M. A. Andreichikov, B. O. Kerbikov, Yu. A. Simonov
We find a new correction to the hydrogen atom ground state hyperfine energy levels splitting in magnetic field. It can be interpreted as magnetic focusing of the wave function at the origin. The effect might be within the reach of experiment.
Multidimensionally-constrained relativistic mean field models and potential energy surfaces of actinide nuclei
nucl-thBing-Nan Lu, Jie Zhao, En-Guang Zhao, Shan-Gui Zhou
By breaking both the axial and the spatial reflection symmetries, we develop multidimensionally constrained relativistic mean field (MDC-RMF) models. The nuclear shape is assumed to be invariant under the reversion of $x$ and $y$ axes, i.e., the intrinsic symmetry group is $V_{4}$ and all shape degrees of freedom $β_{λμ}$ with even $μ$, such as $β_{20}$, $β_
Michael Oberguggenberger
This paper is concerned with the algebraic dual D*(Ω) of the space of test functions D(Ω). The emphasis is on failures and successes of D*(Ω) as compared to the continuous dual D'(Ω), the space of distributions. Topological properties, operations with elements of D*(Ω) and applications to linear partial differential equations are discussed.
Masakazu Matsubara, Alexander Schroer, Andreas Schmehl, Alexander Melville
Ultrafast strengthening or quenching of the ferromagnetic order of semiconducting Eu1-xGdxO was achieved by resonant photoexcitation. The modification of the magnetic order is established within 3 ps as revealed by optical second harmonic generation. A theoretical analysis shows that the response is determined by the interplay of chemically and optically gen
Gautam Bhattacharyya, Biplob Bhattacherjee, Tsutomu T. Yanagida, Norimi Yokozaki
Influenced by the current trend of experimental data, especially from the LHC, we construct a supersymmetric scenario where a natural dynamics makes the squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion of two underlying ideas: ($i$) gauge mediation of su
Coherent microscopy at resolution beyond diffraction limit using post-experimental data extrapolation
physics.opticsTatiana Latychevskaia, Hans-Werner Fink
Conventional microscopic records represent intensity distributions whereby local sample information is mapped onto local information at the detector. In coherent microscopy, the superposition principle of waves holds; field amplitudes are added, not intensities. This non-local representation is spread out in space and interference information combined with w
Gerald Bourgeois
Let $(A_i)_{0\leq i\leq k}$ be generic matrices over $\mathbb{Q}$, the field of rational numbers. Let $K=\mathbb{Q}(E)$, where $E$ denotes the entries of the $(A_i)_i$, and let $\overline{K}$ be the algebraic closure of $K$. We show that the generic unilateral equation $A_kX^k+\cdots+A_1X+A_0=0_n$ has $\binom{nk}{n}$ solutions $X\in\mathcal{M}_n(\overline{K}
Jun Pang, Yang Zhang
The popularity of online social networks (OSNs) makes the protection of users' private information an important but scientifically challenging problem. In the literature, relationship-based access control schemes have been proposed to address this problem. However, with the dynamic developments of OSNs, we identify new access control requirements which c
On the existence of bounded solutions for nonlinear second order neutral difference equations
math.CAMarek Galewski, Magdalena Nockowska Rosiak, Robert Jankowski, Ewa Schmeidel
\noindent Using the techniques connected with the measure of noncompactness we investigate the neutral difference equation of the following form \begin{equation*} Δ\left(r_{n}\left(Δ\left(x_{n}+p_{n}x_{n-k}\right) \right) ^γ\right) +q_{n}x_{n}^α+a_{n}f(x_{n})=0. \end{equation*}% where $x:{\mathbb{N}}_{0}\rightarrow {\mathbb{R}}$, $a,p,q:{\mathbb{N}}%_{0}\rig
Thomas Hudson, Christoph Ortner
We formulate a variational model for a geometrically necessary screw dislocation in an anti-plane lattice model at zero temperature. Invariance of the energy functional under lattice symmetries renders the problem non-coercive. Nevertheless, by establishing coercivity with respect to the elastic strain and a concentration compactness principle, we prove exis
The Peierls-Onsager Effective Hamiltonian in a complete gauge covariant setting: Description of the spectrum
math-phViorel Iftimie, Radu Purice
Using the procedures in \cite{Bu} and \cite{GMS} and the magnetic pseudodifferential calculus we have developped in \cite{MP1,MPR1,IMP1,IMP2} we construct an effective Hamitonian that describes the spectrum in any compact subset of the real axis for a large class of periodic pseudodifferential Hamiltonians in a bounded smooth magnetic field, in a completely
L. Gruber, S. E. Brunner, J. Marton, K. Suzuki
Several types of Silicon Photomultipliers were exposed to short pulsed laser light (~ 30 ps FWHM) with its intensity varying from single photon to well above the number of microcells of the device. We observed a significant deviation of the output of SiPMs from the expected behavior although such response curve is considered to be rather trivial. We also not
L. Herrera, J. Ibáñez, A. Di Prisco
The physical meaning of the vorticity of the matter content in Gödel spacetime is analyzed in some detail. As we shall see, unlike the situation in general stationnary axially symmetric spacetimes (Lewis--Papapetrou), the vorticity in Gödel spacetime is not associated to a circular flow of superenergy on the plane orthogonal to the vorticity vector. This fac
Sound Absorption and Dispersion in Dilute Polyatomic Gases: A Generalized Kinetic Approach
physics.flu-dynSebastian Fischer, Wilson Marques
A generalized kinetic model equation which takes into account the frequency depence of the thermal conductivity is used to analyze the problem of sound propagation in dilute polyatomic gases. By comparing the theoretical results with some available experimental data we infer that our model equation provides a precise transition between low and high-frequency
Gabriel Padilla, Andrés Villaveces
In this article we give an equivariant version for the construction of generic models on presheaves of structures. We deal with first order structures endowed with a suitable action of some fixed group, say $G$; we call them $G$-structures. We show that every exact presheaf of $G$-structures $\mathcal{M}$ has a generic (equivariant) $G$-model $\mathcal{M}^{^
Parameter estimation based on discrete observations of fractional Ornstein-Uhlenbeck process of the second kind
math.PREhsan Azmoodeh, Lauri Viitasaari
Fractional Ornstein-Uhlenbeck process of the second kind $(\text{fOU}_{2})$ is solution of the Langevin equation $\mathrm{d}X_t = -θX_t\,\mathrm{d}t+\mathrm{d}Y_t^{(1)}, \ θ>0$ with Gaussian driving noise $ Y_t^{(1)} := \int^t_0 e^{-s} \,\mathrm{d}B_{a_s}$, where $ a_t= H e^{\frac{t}{H}}$ and $B$ is a fractional Brownian motion with Hurst parameter $H \in (0
Keye Zhang, Pierre Meystre, Weiping Zhang
We propose that the dispersion management of coherent atomic matter waves can be exploited to overcome quantum back-action in condensate-based optomechanical sensors. The effective mass of an atomic Bose-Einstein condensate modulated by an optical lattice can become negative, resulting in a negative-frequency optomechanical oscillator, a negative environment
Paul Bunn, Rafail Ostrovsky
We demonstrate the feasibility of end-to-end communication in highly unreliable networks. Modeling a network as a graph with vertices representing nodes and edges representing the links between them, we consider two forms of unreliability: unpredictable edge-failures, and deliberate deviation from protocol specifications by corrupt nodes. We present a robust
Hongsheng Zhang, Sean A. Hayward, Xiang-Hua Zhai, Xin-Zhou Li
We obtain the Schwarzschild solution from thermodynamic considerations using the assumptions of a quasi local mass form (the Misner-Sharp mass) and geometric surface gravity in a spherically symmetric spacetime. The deduction is extended to other cases such as the de Sitter, anti-de Sitter, Reissner-Nordström and higher dimensional spacetimes. This paper dem
Dali Sun, Mei Fang, Xiaoshan Xu, Lu Jiang
Organic spintronic devices have been appealing because of the long spin life time of the charge carriers in the organic materials and their low cost, flexibility and chemical diversity. In previous studies, the control of resistance of organic spin valves is generally achieved by the alignment of the magnetization directions of the two ferromagnetic electrod
Storage of electromagnetic waves in a metamaterial that mimics electromagnetically induced transparency
physics.opticsToshihiro Nakanishi, Takehiro Otani, Yasuhiro Tamayama, Masao Kitano
We propose a method for dynamically controlling the properties of a metamaterial that mimics electromagnetically induced transparency (EIT) by introducing varactor diodes to manipulate the structural symmetry of the metamaterial. Dynamic modulation of the EIT property enables the storage and retrieval of electromagnetic waves. We confirmed that the electroma
Contrasting Elastic Properties of Heavily B- and N-doped Graphene, with Random Distributions Including Aggregates
cond-mat.mtrl-sciKarolina Z. Milowska, Magdalena Woinska, Malgorzata Wierzbowska
We focused on elastic properties of B- and N-doped graphene in wide range of concentrations up to 20%. The Young's, bulk and shear moduli and Poisson's ratio have been calculated by means of the density functional theory for a representative set of supercells with disordered impurity patterns including aggregates. In contrast to earlier work, it is d
J. A. Hillman
We show that $\mathbb{S}ol^3\times\mathbb{E}^1$-manifolds are Seifert fibred, with general fibre the torus, and base one of the seven flat 2-orbifolds $T, Kb, \mathbb{A}, \mathbb{M}b, S(2,2,2,2), P(2,2)$ or $\mathbb{D}(2,2)$, and outline a classification of such 4-manifolds.
Kieran Smallbone
We have created a genome-scale network reconstruction of chinese hamster ovary (CHO) cell metabolism. Existing reconstructions were improved in terms of annotation standards, to facilitate their subsequent use in dynamic modelling. The resultant network is available from ChoNet (http://cho.sf.net/).
On PROGRESS Operation. How to Make Object-Oriented Programming System More Object-Oriented (DRAFT)
cs.PLEvgeniy Grigoriev
A system, which implements persistent objects, has to provide different opportunities to change the objects in arbitrary ways during their existence. A traditional realization of OO paradigm in modern programming systems has fundamental drawbacks which complicate an implementation of persistent modifiable objects considerably. There is alternative realizatio