July 2007 arXiv papers — page 4
Showing 301–400 of 4,643 papers
Non-equilibrium scaling limit for a tagged particle in the simple exclusion process with long jumps
math.PRMilton D. Jara
We prove an invariance principle for a tagged particle in a simple exclusion process out of equilibrium. The scaling limit is a time-inhomogeneous process of independent increments, related to the solution of a fractional heat equation.
Tuning of ferromagnetism through anion substitution in Ga-Mn-pnictide ferromagnetic semiconductors
cond-mat.mtrl-sciPeter R. Stone, Jeffrey W. Beeman, Kin M. Yu, Oscar D. Dubon
We have synthesized Ga1-xMnxAs1-yPy and Ga1-xMnxP1-yNy by the combination of ion implantation and pulsed-laser melting. We find that the incorporation of isovalent impurities with smaller atomic radii leads to a realignment of the magnetic easy axis in Ga1-xMnxP1-yNy/GaP and Ga1-xMnxAs1-yPy/GaAs thin films from in-plane to out-of-plane. This tensile-strain-i
Turlough Neary, Damien Woods
We give small universal Turing machines with state-symbol pairs of (6, 2), (3, 3) and (2, 4). These machines are weakly universal, which means that they have an infinitely repeated word to the left of their input and another to the right. They simulate Rule 110 and are currently the smallest known weakly universal Turing machines.
Khoa Tran
In this paper, I'll derive the Hamilton-Jacobi (HJ) equation for Merton's problem in Utility Optimization Theory using a Calculus of Variations (CoV) Approach. For stochastic control problems, Dynamic Programming (DP) has been used as a standard method. To the best of my knowledge, no one has used CoV for this problem. In addition, while the DP appro
Jean-Pierre Eckmann, Shimshon Jacobi, Shimon Marom, Elisha Moses
Eytan and Marom recently showed that the spontaneous burst activity of rat neuron cultures includes `first to fire' cells that consistently fire earlier than others. Here we analyze the behavior of these neurons in long term recordings of spontaneous activity of rat hippocampal and rat cortical neuron cultures from three different laboratories. We identi
David M. Bradley
The double zeta function is a function of two arguments defined by a double Dirichlet series, and was first studied by Euler in response to a letter from Goldbach in 1742. By calculating many examples, Euler inferred a closed form evaluation of the double zeta function in terms of values of the Riemann zeta function, in the case when the two arguments are po
Kevin Ann, Gregg Jaeger
We demonstrate the existence of entanglement sudden death (ESD), the complete loss of entanglement in finite time, in qubit-qutrit systems. In particular, ESD is shown to occur in such systems initially prepared in a one-parameter class of entangled mixed states and then subjected to local dephasing noise. Together with previous results, this proves the exis
Quantum interference terms in nonmesonic weak decay of $Λ$-hypernuclei within a RPA formalism
nucl-thE. Bauer
Single and double coincidence nucleon spectra in the $Λ$-hypernuclei weak decay are evaluated and discussed using a microscopic formalism. Nuclear matter is employed together with the local density approximation which allows us to analyze the $^{12}_ΛC$ hypernucleus non-mesonic weak decay. Final state interactions (FSI) are included via the first order (in t
T. R. Greve, D. Stern, R. J. Ivison, C. De Breuck
We present deep 350- and 1200-micron imaging of the region around 4C41.17 -- one of the most distant (z = 3.792) and luminous known radio galaxies -- obtained with the Submillimeter High Angular Resolution Camera (SHARC-II) and the Max Planck Millimeter Bolometer Array (MAMBO). The radio galaxy is robustly detected at 350- and 1200-micron, as are two nearby
Joshua D. Younger, T. J. Cox, Anil C. Seth, Lars Hernquist
We use hydrodynamic simulations of minor mergers of galaxies to investigate the nature of surface brightness excesses at large radii observed in some spiral galaxies: antitruncated stellar disks. We find that this process can produce the antitruncation via two competing effects: (1) merger-driven gas inflows that concentrate mass in the center of the primary
Nilton Penha, Bernhard Rothenstein
We discuss a superluminal unphysical motion which, we believe, has a high pedagogical potential. It highlights the physics behind the concept of simultaneity in special relativity and illustrates the non-physical character of superluminal speeds offering a rewarding exercise in handling the Minkowski space-time diagram.
Excitation mechanisms in newly discovered H2-bearing Damped Lyman-alpha clouds: systems with low molecular fractions
astro-phP. Noterdaeme, C. Ledoux, P. Petitjean, F. Le Petit
We probe the physical conditions in high-redshift damped Ly-alpha systems using the observed molecular fraction and the rotational excitation of molecular hydrogen. We report two new detections of H2 at z = 2.402 and 1.989 toward, respectively, HE 0027-1836 and HE 2318-1107. We also present a detailed analysis of our recent H2 detection toward Q2343+125. All
Current-voltage characteristics of semiconductor/ferromagnet junctions in the spin blockade regime
cond-mat.mes-hallYu. V. Pershin, M. Di Ventra
It was recently predicted [Phys. Rev. B 75, 193301 (2007)] that spin blockade may develop at nonmagnetic semiconductor/perfect ferromagnet junctions when the electron flow is directed from the semiconductor into the ferromagnet. Here we consider current-voltage characteristics of such junctions. By taking into account the contact resistance, we demonstrate a
B. Rosenow, B. I. Halperin, S. H. Simon, Ady Stern
Recent schemes for experimentally probing non-abelian statistics in the quantum Hall effect are based on geometries where current-carrying quasiparticles flow along edges that encircle bulk quasiparticles, which are localized. Here we consider one such scheme, the Fabry-Perot interferometer, and analyze how its interference patterns are affected by a couplin
N. A. Carella
The best deterministic unconditionally proven integer factorization algorithms have exponential running time complexities of O(N^(1/4)) arithmetic operations, and conditional on the Riemann hypothesis, there is a deterministic algorithm of exponential running time complexity O(N^(1/5)). This note proposes a new deterministic integer factorization algorithm o
S. Andringa, P. Assis, M. Pimenta, A. Pina
A new approach to Gamma/Hadron separation algorithms is proposed. The differences between Gamma and Hadron showers are notorious in two main aspects. The first is the wideness of the shower, and the second is the distribution of the angles of emission of Cherenkov photons in respect to the shower main axis. Using more than one IAC telescope, and their respec
M. Asorey, J. F. Carinena, G. Marmo, A. Perelomov
One-dimensional isoperiodic classical systems have been first analyzed by Abel. Abel's characterization can be extended for singular potentials and potentials which are not defined on the whole real line. The standard shear equivalence of isoperiodic potentials can also be extended by using reflection and inversion transformations. We provide a full char
Vincenzo Cirigliano, Ignasi Rosell
We calculate the ratios R_{e/mu}^{(P)} = Gamma(P -> e nu)/Gamma (P -> mu nu) (P=pi,K) in Chiral Perturbation Theory to order e^2 p^4. We complement the one- and two-loop effective theory results with a matching calculation of the local counterterm, performed within the large-$N_C$ expansion. We find R_{e/mu}^{(π)} = (1.2352 \pm 0.0001)*10^{-4} and R_{e/mu}^{
S. Andringa, M. Pato, M. Pimenta
A new method to reconstruct the 3-dimensional structure of extensive air showers, seen by fluorescence detectors, is proposed. The observation of the shower is done in 2-dimensional pixels, for consecutive time bins. Time corresponds to a third dimension. Assuming that the cosmic ray shower propagates as a plane wave front moving at the speed of light, a com
P. Assis, G. Agnetta, P. Brogueira, O. Catalano
GAW proposes a new approach for the detection and measurement of the Cherenkov light produced by GeV/TeV gamma rays traversing the Earth atmosphere which imposes specific requirements on the electronics design. The focal surface of the GAW telescope consists of a matrix of multi-anode photomultipliers. The large number of active channels (of the order of 10^
Nantel Bergeron, Muriel Livernet
The pre-Lie operad can be realized as a space T of labelled rooted trees. A result of F. Chapoton shows that the pre-Lie operad is a free twisted Lie algebra. That is, the S-module T is obtained as the plethysm of the S-module Lie with an S-module F. In the context of species, we construct an explicit basis of F. This allows us to give a new proof of Chapoto
Y. Charles Li
We propose a segment description for turbulent solutions to evolution equations in an effort to develop an effective description rather than the classical Reynolds average. The new description has connections with symbolic dynamics and shadowing technique. The challenge of future study is how to effectively implement the description numerically.
Y. Charles Li
In this article, I will prove a recurrence theorem which says that any $H^s(\mathbb{T}^2)$ (s>2) solution to the 2D Euler equation returns repeatedly to an arbitrarily small $H^0(\mathbb{T}^2)$ neighborhood.
Long-time stable HTSC DC-SQUID gradiometers with silicon dioxide passivation for measurements with superconducting flux transformers
cond-mat.supr-conP Seidel, C Becker, A Steppke, M Buettner
In applications for high-Tc superconducting DC-SQUIDs such as biomagnetism, nondestructive evaluation and the relaxation of magnetic nanoparticles, it is important to maintain reliable sensor performance over an extended time period. We designed and produced DC-SQUID gradiometers based on YBCO thin films which are inductively coupled to a flux transformer to
Y. Charles Li
Nadirashvili presented a beautiful example showing that the Poincaré recurrence does not occur near a particular solution to the 2D Euler equation of inviscid incompressible fluids. Unfortunately, Nadirashvili's setup of the phase space is not appropriate, and details of the proof are missing. This note fixes that.
Monte Carlo studies of supersymmetric matrix quantum mechanics with sixteen supercharges at finite temperature
hep-thKonstantinos N. Anagnostopoulos, Masanori Hanada, Jun Nishimura, Shingo Takeuchi
We present the first Monte Carlo results for supersymmetric matrix quantum mechanics with sixteen supercharges at finite temperature. The recently proposed non-lattice simulation enables us to include the effects of fermionic matrices in a transparent and reliable manner. The internal energy nicely interpolates the weak coupling behavior obtained by the high
E. Katzav, M. Adda-Bedia, M. Ben Amar, A. Boudaoud
We investigate propagating fronts in disordered media that belong to the universality class of wetting contact lines and planar tensile crack fronts. We derive from first principles their nonlinear equations of motion, using the generalized Griffith criterion for crack fronts and three standard mobility laws for contact lines. Then we study their roughness u
Temitope Gbolahan Jaiyeola, Olushola John Adeniran
The existence of A$_ρ$-loops, A$_λ$-loops and A$_μ$-loops that are neither extra loops nor CC-loops such that any two of their inner mappings $R(x,y),L(x,y)$ and $T(x)$ commute while the other one is of order 2 is shown.
B. A. Twarog, L. C. Vargas, B. J. Anthony-Twarog
The metallicity dependence of the primary indices of the uvby photometric system for cooler dwarfs (Teff ~ 6500 K to 5000K) is investigated. The data base for the analysis is composed of the overlap between a composite catalog of selected, high-dispersion spectroscopic abundances for 1801 stars on the metallicity scale of Valenti and Fischer (2005) and a mer
Seiji J. Yamamoto, Qimiao Si
We consider the Fermi surface inside the antiferromagnetic ordered region of a Kondo lattice system in an arbitrary dimension higher than one. We establish the existence of ${\rm AF_S}$, an antiferromagnetic phase whose Fermi surface is ``small,'' in the sense that the local moments do not participate in the Fermi-surface formation. This is in contra
T. Nattermann, V. L. Pokrovsky
A Bose-Einstein condensate in an external potential consisting of a superposition of a harmonic and a random potential is considered theoretically. From a semi-quantitative analysis we find the size, shape and excitation energy as a function of the disorder strength. For positive scattering length and sufficiently strong disorder the condensate decays into f
W. M. Alberico, S. Chiacchiera, H. Hansen, A. Molinari
We consider the shear viscosity of a system of quarks and its ratio to the entropy density above the critical temperature for deconfinement. Both quantities are derived and computed for different modeling of the quark self-energy, also allowing for a temperature dependence of the effective mass and width. The behaviour of the viscosity and the entropy densit
Ignacio Franco, Moshe Shapiro, Paul Brumer
A novel way to induce ultrafast currents in molecular wires using two incident laser frequencies, $ω$ and $2ω$, is demonstrated. The mechanism relies on Stark shifts, instead of photon absorption, to transfer population to the excited states and exploits the temporal profile of the field to generate phase controllable transport. Calculations in a \emph{trans
Reaffirming the connection between the Galactic stellar warp and the Canis Major overdensity
astro-phM. López-Corredoira, Y. Momany, S. Zaggia, A. Cabrera-Lavers
We perform a critical re-analysis and discussion of recent results presented in the literature which interpret the CMa overdensity as the signature of an accreting dwarf galaxy or a new substructure within the Galaxy. Several issues are addressed. We show that arguments against the ``warp'' interpretation are based on an erroneous perception of the M
Proper motions of radiative knots in simulations of stellar jets - An alternative to pulsating inflow conditions
astro-phF. Rubini, S. Lorusso, L. Del Zanna, F. Bacciotti
Elongated jets from young stellar objects typically present a nodular structure, formed by a chain of bright knots of enhanced emission with individual proper motions. Though it is generally accepted that internal shocks play an important role in the formation and dynamics of such structures, their precise origin and the mechanisms behind the observed proper
An application of linear programming duality to discrete Fourier analysis and additive problems
math.COErnie Croot
Suppose that f is a function from Z_p -> [0,1] (Z_p is my notation for the integers mod p, not the p-adics), and suppose that a_1,...,a_k are some places in Z_p. In some additive number theory applications it would be nice to perturb f slightly so that Fourier transform f^ vanishes at a_1,...,a_k, while additive properties are left intact. In the present pap
Hashem Zoubi, Helmut Ritsch
We study electronic excitations of a degenerate gas of atoms trapped in pairs in an optical lattice. Local dipole-dipole interactions produce a long lived antisymmetric and a short lived symmetric superposition of individual atomic excitations as the lowest internal on-site excitations. Due to the much larger dipole moment the symmetric states couple efficie
Technical aspects of an impact acceleration traumatic brain injury rat model with potential suitability for both microdialysis and PtiO2 monitoring
q-bio.NCEmilie Carré, Emmanuel Cantais, Olivier Darbin, Jean-Pierre Terrier
This report describes technical adaptations of a traumatic brain injury (TBI) model-largely inspired by Marmarou-in order to monitor microdialysis data and PtiO2 (brain tissue oxygen) before, during and after injury. We particularly focalize on our model requirements which allows us to re-create some drastic pathological characteristics experienced by severe
A negative-U interpretation of the femto-second laser pulse induced crystallographic expansion of a cuprate HTSC material reported recently by Gedik et al
cond-mat.supr-conJohn A. Wilson
Gedik et al have very recently demonstrated using a pump/probe femto-second laser technique that the c-axis lattice parameter of LaCuO4+d temporarily becomes expanded by as much as 2.5% following pulsed laser optical excitation at 1.55 eV. Access to an out-of-equilibrium metastable excited state is observed to develop on a time scale of 30 ps. Subsequently t
Examination of unitarity condition (positive definiteness of expression for transition probabilities) at three neutrino oscillations in vacuum
hep-phKh. M. Beshtoev
This work has shown that at strict fulfilment of condition $Δm^2_{1 3} = Δm^2_{1 2} + Δm^2_{2 3}$ the expression for probability of $ν_e \to ν_e$ transitions $P_{ν_e \to ν_e}(t)$ is positively defined at every values of $θ$ and $β$ while at any arbitrarily small deviation from this condition it becomes negative. In order to make this expression for probabili
Elliptic Flow, Initial Eccentricity and Elliptic Flow fluctuations in Heavy Ion Collisions at RHIC
nucl-exRachid Nouicer
We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu coll
A. F. Zakharov, A. A. Nucita, F. De Paolis, G. Ingrosso
The existence of dark matter (DM) at scales of few pc down to $\simeq 10^{-5}$ pc around the centers of galaxies and in particular in the Galactic Center region has been considered in the literature. Under the assumption that such a DM clump, principally constituted by non-baryonic matter (like WIMPs) does exist at the center of our galaxy, the study of the
B. Sánchez-Andrade Nuño, R. Centeno, K. G. Puschmann, J. Trujillo Bueno
Off-the-limb observations with high spatial and spectral resolution will help us understand the physical properties of spicules in the solar chromosphere Spectropolarimetric observations of spicules in the \ion{He}{i} 10830 Å multiplet were obtained with the Tenerife Infrared Polarimeter on the German Vacuum Tower Telescope at the Observatorio del Teide (Ten
Xuepeng Chen, Ralf Launhardt, Thomas Henning
We present the results of an interferometric study of the N2H+(1--0) emission from nine nearby, isolated, low-mass protostellar cores, using the OVRO millimeter array. The main goal of this study is the kinematic characterization of the cores in terms of rotation, turbulence, and fragmentation. Eight of the nine objects have compact N2H+ cores with FWHM radi
Transient termination of synaptically sustained spiking by stochastic inputs in a pair of coupled Type 1 neurons
q-bio.NCBoris S. Gutkin, Juergen Jost, Henry C. Tuckwell
We examine the effects of stochastic input currents on the firing behavior of two excitable neurons coupled with fast excitatory synapses. In such cells (models), typified by the quadratic integrate and fire model, mutual synaptic coupling can cause sustained firing or oscillatory behavior which is necessarily antiphase. Additive Gaussian white noise can tra
K. Martens
The High Resolution Fly's Eye Experiment (HiRes) measures cosmic rays (CR) at the highest energies using the air fluorescence technique. As data taking on the Dugway Proving Grounds in Western Utah is finished, the HiRes data are relevant for cosmogenic neutrinos in two different ways. We first use our best fit to the measured HiRes CR spectrum together
Balazs Kozma, Alain Barrat
The structure of a network can significantly influence the properties of the dynamical processes which take place on them. While many studies have been devoted to this influence, much less attention has been devoted to the interplay and feedback mechanisms between dynamical processes and network topology on adaptive networks. Adaptive rewiring of links can h
Relative abundances of cosmic ray nuclei B-C-N-O in the energy region from 10 GeV/n to 300 GeV/n. Results from ATIC-2 (the science flight of ATIC)
astro-phA. D. Panov, N. V. Sokolskaya, J. H. Adams,, H. S. Ahn
The ATIC balloon-borne experiment measures the energy spectra of elements from H to Fe in primary cosmic rays from about 100 GeV to 100 TeV. ATIC is comprised of a fully active bismuth germanate calorimeter, a carbon target with embedded scintillator hodoscopes, and a silicon matrix that is used as the main charge detector. The silicon matrix produces good c
Josephson effect in thin-film superconductor/insulator/superconductor junctions with misaligned in-plane magnetic fields
cond-mat.supr-conJ. Linder, A. Sudbø
We study a tunnel junction consisting of two thin-film s-wave superconductors separated by a thin, insulating barrier in the presence of misaligned in-plane exchange fields. We find an interesting interplay between the superconducting phase difference and the relative orientation of the exchange fields, manifested in the Josephson current across the junction
K. Hicks, T. Mibe, M. Sumihama
Cross sections for the $γp \to K^+ Λ$ have been measured at backward angles using linearly polarized photons in the range 1.50 to 2.37 GeV. In addition, the beam asymmetry for this reaction has been measured for the first time at backward angles. The $Λ$ was detected at forward angles in the LEPS spectrometer via its decay to $pπ^-$ and the K^+ was inferred
S. Khan, B. Chakraborty, F. G. Scholtz
We consider the problem of a degenerate electron gas in the background of a uniformly distributed positive charge, ensuring overall neutrality of the system, in the presence of non-commutativity. In contrast to previous calculations that did not include twisted statistics, we find corrections to the ground state energy already at first order in perturbation
Time-resolved refractive index and absorption mapping of light-plasma filaments in water
physics.opticsStefano Minardi, Amrutha Gopal, Michael Tatarakis, Arnaud Couairon Gintaras Tamosauskas
By means of a quantitative shadowgraphic method, we performed a space-time characterization of the refractive index variation and transient absorption induced by a light-plasma filament generated by a 100 fs laser pulse in water. The formation and evolution of the plasma channel in the proximity of the nonlinear focus were observed with a 23 fs time resoluti
Relativistic nature of a magnetoelectric modulus of Cr_2O_3-crystals: a new 4-dimensional pseudoscalar and its measurement
cond-mat.otherFriedrich W. Hehl, Yuri N. Obukhov, Jean-Pierre Rivera, Hans Schmid
Earlier, the magnetoelectric effect of chromium sesquioxide Cr_2O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2O_3 crystals or the magnetic field-induced polarization. From the magnetoelectric moduli of Cr_2O_3 we extract a 4-dimensional relativistic invariant pseudoscalar $\w
Dirac-fermions and conductance-oscillations in (s,d)-wave superconductor/normal graphene junctions
cond-mat.supr-conJ. Linder, A. Sudbø
We investigate quantum transport in a normal/superconductor graphene heterostructure, including the possibility of an anisotropic pairing potential in the superconducting region. We find that under certain circumstances, the conductance displays an undamped, oscillatory behaviour as a function of applied bias voltage. Also, we investigate how the conductance
R. Plaga
It is generally considered as self evident that the lifetime of our vacuum in the landscape of string theory cannot be much shorter than the current age of the universe. Here I show why this lower limit is invalid. A certain type of ``parallel universes'' is a necessary consequence of the string-landscape dynamics and might well allow us to ``survive
Mario Ziman, Vladimir Buzek
A set of all states of a bi-partite quantum system can be divided into subsets each of which contains states with the same degree of entanglement. In this paper we address a question whether local operations (without classical communication) affect the entanglement-induced state ordering. We show that arbitrary unilocal channel (i.e., a channel that acts on
N. Voglis, M. Harsoula, G. Contopoulos
We study the orbital structure of a self-consistent N-body equilibrium configuration of a barred galaxy constructed from cosmological initial conditions. The value of its spin parameter L is near the observed value of our Galaxy L=0.22. We classify the orbits in regular and chaotic using a combination of two different methods and find 60% of them to be chaot
Mikael Vejdemo-Johansson
The author presents a computer implementation, calculating the terms of the Saneblidze-Umble diagonals on the permutahedron and the associahedron. The code is analyzed for correctness and presented in the paper, the source code of which simultaneously represents both the paper and the program.
Ultracold collisions in magnetic fields: reducing inelastic cross sections near Feshbach resonances
physics.chem-phR. Adam Rowlands, Maykel Leonardo Gonzalez-Martinez, Jeremy M. Hutson
We have carried out bound-state and low-energy quantum scattering calculations on He + NH (triplet Sigma) in magnetic fields, with the NH molecule in its n=1 rotationally excited states. We have explored the pattern of levels as a function of magnetic field and identified the nearly good quantum numbers in different regimes. We have used the bound-state calc
T. P. Polak, E. Sarnelli
Theory of self induced resonances in asymmetric two-junction interferometer device is presented. In real devices it is impossible to have an ideal interferometer free of imperfections. Thus, we extended previous theoretical approaches introducing a model which contains several asymmetries: Josephson current $ε$, capacitances $χ$ and dissipation $ρ$ presented
Control of the Casimir force by the modification of dielectric properties with light
cond-mat.stat-mechF. Chen, G. L. Klimchitskaya, V. M. Mostepanenko, U. Mohideen
The experimental demonstration of the modification of the Casimir force between a gold coated sphere and a single-crystal Si membrane by light pulses is performed. The specially designed and fabricated Si membrane was irradiated with 514 nm laser pulses of 5 ms width in high vacuum leading to a change of the charge-carrier density. The difference in the Casi
Andrew W. Appel, Sandrine Blazy
Cminor is a mid-level imperative programming language; there are proved-correct optimizing compilers from C to Cminor and from Cminor to machine language. We have redesigned Cminor so that it is suitable for Hoare Logic reasoning and we have designed a Separation Logic for Cminor. In this paper, we give a small-step semantics (instead of the big-step of the
S. Grenier, K. J. Thomas, J. P. Hill, U. Staub
We report the observation of superstructures associated with the oxygen 2p-states in two prototypical manganites using x-ray diffraction at the oxygen K-edge. We determine the nature of the orderings and discuss our picture with respect to novel theoretical models. In the stripe order system Bi0.31 Ca0.69 MnO3, hole-doped O states are found to be orbitally o
Backward stochastic differential equations with random stopping time and singular final condition
math.PRA. Popier
In this paper we are concerned with one-dimensional backward stochastic differential equations (BSDE in short) of the following type: \[Y_t=ξ-\int_{t\wedge τ}^τY_r|Y_r|^q dr-\int_{t\wedge τ}^τZ_r dB_r,\qquad t\geq 0,\] where $τ$ is a stopping time, $q$ is a positive constant and $ξ$ is a $\mathcal{F}_τ$-measurable random variable such that $\mathbf{P}(ξ=+\in
Qun Chen, Juergen Jost, Guofang Wang
We develop analytical methods for nonlinear Dirac equations. Examples of such equations include Dirac-harmonic maps with curvature term and the equations describing the generalized Weierstrass representation of surfaces in three-manifolds. We provide the key analytical steps, i.e., small energy regularity and removable singularity theorems and energy identit
Quantum rotor description of the Mott-insulator transition in the Bose-Hubbard model
cond-mat.stat-mechT. P. Polak, T. K. Kopeć
We present the novel approach to the Bose-Hubbard model using the $\mathrm{U}(1)$ quantum rotor description. The effective action formalism allows us to formulate a problem in the phase only action and obtain an analytical formulas for the critical lines. We show that the nontrivial $\mathrm{U}(1)$ phase field configurations have an impact on the phase diagr
Matteo Petrera, Yuri B. Suris
This paper deals with a remarkable integrable discretization of the so(3) Euler top introduced by Hirota and Kimura. Such a discretization leads to an explicit map, whose integrability has been understood by finding two independent integrals of motion and a solution in terms of elliptic functions. Our goal is the construction of its Hamiltonian formulation.
Enrico Ramirez-Ruiz, Ken-Ichi Nishikawa, Christian B. Hededal
We investigate here the effects of plasma instabilities driven by rapid electron/positron pair cascades, which arise in the environment of GRB sources as a result of back-scattering of a seed fraction of the original spectrum. The injection of electron/positron pairs induces strong streaming motions in the ambient medium. One therefore expects the pair-enric
Vittorio Soma, Piotr Bozek
We calculate the equation of state of nuclear matter in the self-consistent T-matrix scheme including three-body nuclear interactions. We study the effect of the three-body force on the self-energies and spectral functions of nucleons in medium.
M. H. Al-Hashimi, U. -J. Wiese
We consider a particle moving on a cone and bound to its tip by $1/r$ or harmonic oscillator potentials. When the deficit angle of the cone divided by $2 π$ is a rational number, all bound classical orbits are closed. Correspondingly, the quantum system has accidental degeneracies in the discrete energy spectrum. An accidental SU(2) symmetry is generated by
F. Evers, A. D. Mirlin
The physics of Anderson transitions between localized and metallic phases in disordered systems is reviewed. The term ``Anderson transition'' is understood in a broad sense, including both metal-insulator transitions and quantum-Hall-type transitions between phases with localized states. The emphasis is put on recent developments, which include: mult
G. Catalan, H. Bea, S. Fusil, M. Bibes
We have analyzed the morphology of ferroelectric domains in very thin films of multiferroic BiFeO3. Unlike the more common stripe domains observed in thicker films BiFeO3 or in other ferroics, the domains tend not to be straight, but irregular in shape, with significant domain wall roughening leading to a fractal dimensionality. Also contrary to what is usua
Gang Wu, Jinming Dong
Using the method of adiabatic invariants and the Born-Oppenheimer approximation, we have successfully got the excited-state wave functions for a pair of coupled oscillators in the so-called \textit{semiquantum chaos}. Some interesting characteristics in the \textit{Fourier spectra} of the wave functions and its \textit{Correlation Functions} in the regular a
François Béguin, Sylvain Crovisier, Tobias Jaeger, Frédéric Le Roux
We construct different types of quasiperiodically forced circle homeomorphisms with transitive but non-minimal dynamics. Concerning the recent Poincaré-like classification for this class of maps of Jaeger-Stark, we demonstrate that transitive but non-minimal behaviour can occur in each of the different cases. This closes one of the last gaps in the topologic
Bruno Gaujal, Stefan Haar, Jean Mairesse
In a live and bounded Free Choice Petri net, pick a non-conflicting transition. Then there exists a unique reachable marking in which no transition is enabled except the selected one. For a routed live and bounded Free Choice net, this property is true for any transition of the net. Consider now a live and bounded stochastic routed Free Choice net, and assum
A model for the study of the Shubnikov-de Haas and the integer quantum Hall effects in a two dimensional electronic system
cond-mat.mes-hallM. A. Hidalgo R. Cangas
Up to know all the experimental results concerning the integer and fractional quantum Hall effect are related to semiconductor heterostructures (and more recently with graphene). The common characteristic of all these systems is the presence of a reservoir of electrons, which, in fact, in the initial stage is the source of the electrons, providing the two-di
G. Agnetta, P. Assis, B. Biondo, P. Brogueira
The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are refle
J Bauer, A Oguri, AC Hewson
We present a detailed study of the spectral properties of a locally correlated site embedded in a BCS superconducting medium. To this end the Anderson impurity model with superconducting bath is analysed by numerical renormalisation group (NRG) calculations. We calculate one and two-particle dynamic response function to elucidate the spectral excitation and
Christian Jansson
This paper presents rigorous forward error bounds for linear conic optimization problems. The error bounds are formulated in a quite general framework; the underlying vector spaces are not required to be finite-dimensional, and the convex cones defining the partial ordering are not required to be polyhedral. In the case of linear programming, second order co
Sevdzhan Hakkaev, Iliya D. Iliev, Kiril Kirchev
We study the existence and stability of periodic travelling-wave solutions for generalized Benjamin-Bona-Mahony and Camassa-Holm equations. To prove stability, we use the abstract results of Grillakis-Shatah-Strauss and the Floquet theory for periodic eigenvalue problems.
F. L. Schoeier, D. Fong, J. H. Bieging, D. J. Wilner
H13CN J=8-7 sub-millimetre line emission produced in the circumstellar envelope around the extreme carbon star IRC+10216 has been imaged at sub-arcsecond angular resolution using the SMA. Supplemented by a detailed excitation analysis the average fractional abundance of H13CN in the inner wind (< 5E15 cm) is estimated to be about 4E-7, translating into a tot
Gang Wu, Jinming Dong
Heat conduction of a real quasi-one dimensional material, the finite length carbon nanowire (CNW), inserted into the single-walled carbon nanotube (SWNT) has been studied by the molecular dynamical (MD) method, in which both of the longitudinal as well as transverse motions of the chain atoms in the SWNT have been permitted. It is found that the thermal cond
Toshiro Watanabe
A necessary and sufficient condition for the almost sure existence of an absolutely continuous (with respect to the branching measure) exact Hausdorff measure on the boundary of a Galton--Watson tree is obtained. In the case where the absolutely continuous exact Hausdorff measure does not exist almost surely, a criterion which classifies gauge functions $ϕ$
Gang Wu, Jian Zhou, Jinming Dong
The radial-breathing-like phonon modes (RBLMs) of the double-walled carbon nanotubes are studied in a simple analytical model, in which the interaction force constants (FCs) can be obtained analytically from the continuous model. The RBLMs frequencies are obtained by solving the dynamical matrix, and their relationship with the tube radii can be obtained ana
Moderate deviations and laws of the iterated logarithm for the local times of additive Lévy processes and additive random walks
math.PRXia Chen
We study the upper tail behaviors of the local times of the additive Lévy processes and additive random walks. The limit forms we establish are the moderate deviations and the laws of the iterated logarithm for the L_2-norms of the local times and for the local times at a fixed site.
Spatial clustering in the ESO-Sculptor Survey: two-point correlation functions by galaxy type at redshifts 0.1 - 0.5
astro-phValerie De Lapparent, Eric Slezak
We calculate the spatial two-point auto and cross-correlation functions for the 765 galaxies with Rc<21.5 and 0.1<z<0.51 in the ESO-Sculptor survey, and explore the segregation effects among the populations of giant (early-type, late spiral) and dwarf (dE, dI) galaxies. At separation of 0.3 h^-1 Mpc, pairs of early-type galaxies dominate the clustering over
Gang Wu, Jian Zhou, Jinming Dong
With the empirical bond polarizability model, the nonresonant Raman spectra of the chiral and achiral single-wall carbon nanotubes (SWCNTs) under uniaxial and torsional strains have been systematically studied by \textit{ab initio} method. It is found that both the frequencies and the intensities of the low-frequency Raman active modes almost do not change i
M. C. Maccarone, P. Assis, O. Catalano, G. Cusumano
GAW is a "path-finder" experiment to test the feasibility of a new generation of Imaging Atmospheric Cherenkov telescopes that join high flux sensitivity with large field of view capability using Fresnel lens, stereoscopic observational approach, and single photon counting mode. GAW is an array of three telescopes that will be erected at the Calar Al
A. V. Nikulov
Most experts reject the quantum potential introduced by David Bohm in 1952. But it is impossible to describe some quantum mesoscopic phenomena observed in superconductor nanostructures without a quantum force.
Eros Mariani, Felix von Oppen
Rotation and reflection symmetries impose that out-of-plane (flexural) phonons of free-standing graphene membranes have a quadratic dispersion at long wavelength and can be excited by charge carriers in pairs only. As a result, we find that flexural phonons dominate the phonon contribution to the resistivity $ρ$ below a crossover temperature T_x where we obt
C. S. Liu, W. C. Wu
An antiferromagnetic (AF) spin fluctuation induced pairing model is proposed for the electron-doped cuprate superconductors. It suggests that, similar to the hole-doped side, the superconducting gap function is monotonic d_{x^2-y^2}-wave and explains why the observed gap function has a nonmonotonic d_{x^2-y^2}-wave behavior when an AF order is taken into acc
K. Bhattacharya, G. Mukherjee, S. S. Manna
Bilateral trade relationships in the international level between pairs of countries in the world give rise to the notion of the International Trade Network (ITN). This network has attracted the attention of network researchers as it serves as an excellent example of the weighted networks, the link weight being defined as a measure of the volume of trade betw
Effect of Protonation on the electronic properties of DNA base pairs: Applications for molecular electronics
cond-mat.mtrl-sciSairam S. Mallajosyula, Swapan K Pati
Protonation of DNA basepairs is a reversible phenomenon which can be controlled by tuning the pH of the system. Under mild acidic conditions, the hydrogen bonding pattern of the DNA basepairs undergoes a change. We study the effect of protonation on the electronic properties of the DNA basepairs to probe for possible molecular electronics applications. We fi
A. W. C. Lau, D. Lacoste, K. Mallick
We investigate theoretically the violations of Einstein and Onsager relations, and the efficiency for a single processive motor operating far from equilibrium using an extension of the two-state model introduced by Kafri {\em et al.} [Biophys. J. {\bf 86}, 3373 (2004)]. With the aid of the Fluctuation Theorem, we analyze the general features of these violati
Kosuke Sato, Kyoko Matsushita, Yoshitaka Ishisaki, Noriko Y. Yamasaki
We carried out 3 observations of the cluster of galaxies AWM 7, for the central region and 20'-east and 20'-west offset regions, with Suzaku. Temperature and abundance profiles are measured out to 27'~ 570 /h_70 kpc, which corresponded to ~0.35 r_180. The temperature of the intra-cluster medium (ICM) slightly decreases from 3.8 keV at the center
Raman characteristic peaks induced by the topological defects of Carbon Nanotube Intramolecular Junction
cond-mat.mes-hallGang Wu, Jinming Dong
The vibrational modes of some single wall carbon nanotube (SWNT) intramolecular junctions (IMJs) have been calculated using the newest Brenner reactive empirical bond order (REBO) potential, based upon which their nonresonant Raman spectra have been further calculated using the empirical bond polarizability model. It is found that the Raman peaks induced by
The radial breathing-like mode of the collapsed Single-walled carbon nanotube bundle under hydrostatic pressure
cond-mat.mes-hallGang Wu, Xiaoping Yang, Jinming Dong
Using the first principles calculations we have studied the vibrational modes and Raman spectra of a (10, 10) single-walled carbon nanotube (SWNT) bundle under hydrostatic pressure. Detailed analysis shows that the original radial breathing mode (RBM) of the SWNT bundle disappears after the structural phase transition (SPT). And significantly a RBM-like mode
Double Lepton Polarization in $Λ_b -->Λl^+ l^-$ Decay in the Standard Model with Fourth Generations Scenario
hep-phF. Zolfagharpour, V. Bashiry
This study investigates the influence of the fourth generation quarks on the double lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase \{60^\circ,90^\circ,120^\circ\}. We will try to obtain a constrain on the mass of the 4th generation top like quark t', which is consistent with t
O. Tajima, M Hazumi
We report the first search for CP violating decays of the $Υ(4S)$ using a data sample that contains 535 million $Υ(4S)$ mesons with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of $4 \times 10^
Strongly-correlated multi-particle transport in one-dimension through a quantum impurity: an outline of exact and complete solutions
quant-phJung-Tsung Shen, Shanhui Fan
We consider the transport properties of multiple-particle quantum states in a class of one-dimensional systems with a single quantum impurity. In these systems, the local interaction at the quantum impurity induces strong and non-trivial correlations between the multi-particles. We outline an exact theoretical approach, based upon real-space equations of mot