March 2007 arXiv papers — page 5

Marco Picariello

We compute the effect of non diagonal neutrino mass in l_i -> l_j gamma in SUSY theories with non trivial Quark-Lepton complementarity and a flavor symmetry. The correlation matrix V_M=U_{CKM}U_{PMNS} is such that its (1,3) entry, as preferred by the present experimental data, is zero. We do not assume that $V_M$ is bimaximal. Quark-Lepton complementarity an

Nikolay A. Kostov, Vladimir S. Gerdjikov, Tihomir I. Valchev

We present two new families of stationary solutions for equations of Bose-Fermi mixtures with an elliptic function potential with modulus $k$. We also discuss particular cases when the quasiperiodic solutions become periodic ones. In the limit of a sinusoidal potential ($k\to 0$) our solutions model a quasi-one dimensional quantum degenerate Bose-Fermi mixtu

Arthemy V. Kiselev, Johan W. van de Leur

Let F be a smooth real manifold with a linear connection in the tangent bundle. How can we extend the coefficients of the connection to bi-differential operators that incorporate the original structure at zero order? Take a constant mapping of F to a point. Suppose that the point belongs to another manifold M^n. Consider a fibre bundle over M^n with fibres F

J. Clark, I. S. Heng, M. Pitkin, G. Woan

The excitation of quadrupolar quasi-normal modes in a neutron star leads to the emission of a short, distinctive, burst of gravitational radiation in the form of a decaying sinusoid or `ring-down'. We present a Bayesian analysis method which incorporates relevant prior information about the source and known instrumental artifacts to conduct a robust sear

Stephon Alexander, Nicolas Yunes

We study Chern-Simons (CS) gravity in the parameterized post-Newtonian (PPN) framework through a weak-field solution of the modified field equations. We find that CS gravity possesses the same PPN parameters as general relativity, except for the inclusion of a new term, proportional to the CS coupling and the curl of the PPN vector potential. This new term l

Oyvind Gron, Steinar Johannesen

We find a class of solutions of Einstein's field equations representing spacetime outside a spinning cosmic string surrounded by a gas of non-spinning cosmic strings, and show that there exist closed timelike geodesics in this spacetime.

Juan G. Diaz Ochoa, Elena Ramirez Barrios

We present a model of interpersonal comparisons appearing as a generalization of a multi-state model for elements with internal bias. Within this model agents suffering under dissatisfaction compare them with their neighbors. The internal bias are the pre-formed preferences, and the states are represented by the visual contacts that an agent makes to the bas

Nguyen Van Minh

In this paper we present an extension of the Katznelson-Tzafriri Theorem to the asymptotic behavior of individual solutions of evolution equations $u'(t) =Au(t)+f(t)$. The obtained results do not require the uniform continuity of solutions as well as the well-posedness of the equations. The method of study is based on a recently developed approach to the

V. A. Kuz'menko

In the e-print arXiv:1110.2774 the authors study the infrared multiple-photon induced dissociation (IRMPD) of cooled polyatomic ion species. Here we propose a physical explanation of the obtained experimental results and its simple experimental test.

Ivan Balog, Katarina Uzelac

The invaded cluster approach is extended to 2D Potts model with annealed vacancies by using the random-cluster representation. Geometrical arguments are used to propose the algorithm which converges to the tricritical point in the two-dimensional parameter space spanned by temperature and the chemical potential of vacancies. The tricritical point is identifi

David Leonard, Paul Mansfield

We outline a remarkably efficient method for generating solutions to quantum anharmonic oscillators with an x^{2M} potential. We solve the Schroedinger equation in terms of a free parameter which is then tuned to give the correct boundary condition by generating a power series expansion of the wavefunction in x and applying a modified Borel resummation techn

Wu-Sheng Dai, Mi Xie

For a given spectrum {lambda_{n}} of the Laplace operator on a Riemannian manifold, in this paper, we present a relation between the counting function N(lambda), the number of eigenvalues (with multiplicity) smaller than λ, and the heat kernel K(t), defined by K(t)=\sum_{n}e^{-lambda_{n}t}. Moreover, we also give an asymptotic formula for N(λ) and discuss wh

Sorin Dumitrescu, Abdelghani Zeghib

We study 3-dimensional non-Riemannian Lorentz geometries, i.e. compact locally homogeneous Lorentz 3-manifolds with non-compact (local) isotropy group. One result is that, up to a finite cover, all such manifolds admit Lorentz metrics of (non-positive) constant sectionnal curvature. If the geometry is maximal, then the metric has constant sectionnal curvatur

Mohammad R. Garousi, Ahmad Ghodsi

We examine in details the entropy function formalism for non-extremal D3, M2, and M5-branes that their throat approximation is given by Schwarzschild black hole in AdS_{p+2} \times S^{D-(p+2)}. We show that even though there is no attractor mechanism in the non-extremal black holes/branes, the entropy function formalism does work and the entropy is given by

M. Feito, F. J. Cao

Closed-loop or feedback controlled ratchets are Brownian motors that operate using information about the state of the system. For these ratchets, we compute the power output and we investigate its relation with the information used in the feedback control. We get analytical expressions for one-particle and few-particle flashing ratchets, and we find that the

Lech Longa, Grzegorz Pająk, Thomas Wydro

We study the influence of fluctuations in molecular shape on the stability of the biaxial nematic phase by generalizing the mean field model of Mulder and Ruijgrok [Physica A {\bf 113}, 145 (1982)]. We limit ourselves to the case when the molecular shape anisotropy, represented by the alignment tensor, is a random variable of an annealed type. A prototype of

Manuel Freire, Manuel Cebrian, Emilio del Rosal

Plagiarism detection in educational programming assignments is still a problematic issue in terms of resource waste, ethical controversy, legal risks, and technical complexity. This paper presents AC, a modular plagiarism detection system. The design is portable across platforms and assignment formats and provides easy extraction into the internal assignment

Abraham Loeb

According to recent general-relativistic simulations, the coalescence of two spinning black holes (BHs) could lead to recoil speeds of the BH remnant of up to thousands of km/s as a result of the emission of gravitational radiation. Such speeds would enable the merger product to escape its host galaxy. Here we examine the circumstances resulting from a gas-r

B. Loeillet, F. Bouchy, M. Deleuil, F. Royer

The discovery of the short-period giant exoplanet population, the so-called hot Jupiter population, and their link to brown dwarfs and low-mass stars challenges the conventional view of planet formation and evolution. We took advantage of the multi-fiber facilities GIRAFFE and FLAMES-UVES (VLT) to perform the first large radial velocity survey using a multi-

David Harari, Tamas Szamuely

Building upon our arithmetic duality theorems for 1-motives, we prove that the Manin obstruction related to a finite subquotient $\Be (X)$ of the Brauer group is the only obstruction to the Hasse principle for rational points on torsors under semiabelian varieties over a number field, assuming the finiteness of the Tate-Shaferevich group of the abelian quoti

Claudio Garola, Sandro Sozzo

Most physicists uphold that the tests of the Bell inequalities (BI) performed up to now confirm the predictions of standard quantum mechanics (SQM) and refute local realism. But some scholars criticize this conviction, defending local realism in various ways. We present here a new viewpoint based on an improved version of the extended semantic realism (ESR)

Sonja Koller, Leonhard Mayrhofer, Milena Grifoni

We investigate linear and nonlinear transport in interacting single wall carbon nanotubes (SWCNTs) that are weakly attached to ferromagnetic leads. For the reduced density matrix of a SWCNT quantum dot, equations of motion which account for an arbitrarily vectored polarisation of the contacts are derived. We focus on the case of large diameter nanotubes wher

Marco Martins Afonso

We study the statistics of the relative separation between two fluid particles in a spatially smooth and temporally random flow. The Lagrangian strain is modelled by a telegraph noise, which is a stationary random Markov process that can only take two values with known transition probabilities. The simplicity of the model enables us to write closed equations

Gregory Falkovich, Marco Martins Afonso

We study the statistics of the relative separation between two fluid particles in a spatially smooth and temporally random flow. The Lagrangian strain is modelled by a telegraph noise, which is a stationary random Markov process that can only take two values with known transition probabilities. The simplicity of the model enables us to write closed equations

Mitsuru Hamada

A conjugate code pair is defined as a pair of linear codes either of which contains the dual of the other. A conjugate code pair represents the essential structure of the corresponding Calderbank-Shor-Steane (CSS) quantum error-correcting code. It is known that conjugate code pairs are applicable to quantum cryptography. In this work, a polynomial constructi

Masakazu Sano, Hisao Suzuki

We consider the cosmological models for the higher dimensional spacetime which includes the curvatures of our space as well as the curvatures of the internal space. We find that the condition for the integrability of the cosmological equations is that the total space-time dimensions are D=10 or D=11 which is exactly the conditions for superstrings or M-theor

Hylke B. J. Koers, Dimitrios Giannios

We consider gamma-ray burst outflows with a substantial neutron component that are either dominated by thermal energy (fireballs) or by magnetic energy. In the latter case, we focus on the recently introduced `AC' model which relies on magnetic reconnection to accelerate the flow and power the prompt emission. For both the fireball and the AC model, we i

Bogdan Ranguelov, Vesselin Tonchev, Hiroo Omi, Alberto Pimpinelli

We formulate a new (1+1)D step model of potentially unstable vicinal growth that we call "C+ - C-" model and study the step bunching process in it. The basic assumption is that the equilibrium adatom concentrations on both sides of the step are different and this may cause destabilization of the regular step train. We deduce equations of step motion

Adil Belhaj, Pablo Diaz, Antonio Segui

Based on the result of string/string duality, we construct the six dimensional Yang monopole in terms of Type IIA wrapped D-branes. In particular, we show that all the information of such a magnetic solution can be encoded in the K3 surface compactification in the presence of D2 and D4-branes wrapping its non trivial cycles. We give a geometrical and physica

D. C. Rapaport

Discrete particle simulations are used to model segregation in granular mixtures of three different particle species in a horizontal rotating drum. Axial band formation is observed, with medium-size particles tending to be located between alternating bands of big and small particles. Partial radial segregation also appears; it precedes the axial segregation

D. Stich, J. H. Jiang, T. Korn, R. Schuh

In time-resolved Faraday rotation experiments we have detected an inplane anisotropy of the electron spin-dephasing time (SDT) in an $n$--modulation-doped GaAs/Al$_{0.3}$Ga$_{0.7}$As single quantum well. The SDT was measured with magnetic fields of $B\le 1$ T, applied in the $[110]$ and $[1\bar{1}0]$ inplane crystal directions of the GaAs quantum well. For f

Gergely Palla, Illes J. Farkas, Peter Pollner, Imre Derenyi

A search technique locating network modules, i.e., internally densely connected groups of nodes in directed networks is introduced by extending the Clique Percolation Method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analyticall

I. Nandori, U. D. Jentschura, S. Nagy, K. Sailer

We find a mapping of the layered sine-Gordon model to an equivalent gas of topological excitations and determine the long-range interaction potentials of the topological defects. This enables us to make a detailed comparison to the so-called layered vortex gas, which can be obtained from the layered Ginzburg-Landau model. The layered sine-Gordon model has be

Roderick C. Dewar, Annabel Porte

Recently there has been growing interest in the use of Maximum Relative Entropy (MaxREnt) as a tool for statistical inference in ecology. In contrast, here we propose MaxREnt as a tool for applying statistical mechanics to ecology. We use MaxREnt to explain and predict species abundance patterns in ecological communities in terms of the most probable behavio

Donald Marolf, Amitabh Virmani

We perform a holographic renormalization of gravity duals to little string theories. In particular, we construct counterterms which yield a well-defined type II action for NS-sector linear dilaton backgrounds. Our methods are based on a similar recent construction in asymptotically flat spacetimes, and our work demonstrates in detail the parallels between as

Xian-Hui Ge

We derive the Friedmann-like equations in braneworld cosmology by imposing the first law of thermodynamics and Bekenstein's area-entropy formula on the apparent horizon of a Friedmann-Roberston-Walker universe in both Randall-Sundrum II gravity and Dvali-Gabadadze-Porrati gravity models. Israel's boundary condition plays an important role in our calc

I. A. Todoshchenko, H. Alles, H. J. Junes, A. Ya. Parshin

We have measured the melting pressure and pressure in the liquid at constant density of ultra-pure $^4$He (0.3 ppb of $^3$He impurities) with the accuracy of about 0.5 $μ$bar in the temperature range from 10 to 320 mK. Our measurements show that the anomaly on the melting curve below 80 mK which we have recently observed is entirely due to an anomaly in the

V. A. Miransky

I describe the dynamics in recently revealed phases with vector condensates of gauge fields in dense QCD (gluonic phase) and other gauge models. In this case, the Higgs mechanism is provided by condensates of gauge (or gauge plus scalar) fields. Because most of the initial symmetries in such systems are spontaneously broken, their dynamics is very rich. In p

Emmanuel Lochin, Pascal Anelli

Since the proposition of Quality of Service architectures by the IETF, the interaction between TCP and the QoS services has been intensively studied. This paper proposes to look forward to the results obtained in terms of TCP throughput guarantee in the DiffServ Assured Forwarding (DiffServ/AF) service and to present an overview of the different proposals to

T. Ueda, K. Sasaki, T. Uematsu

We investigate the unpolarized virtual photon structure functions $F_2^gamma(x,Q^2,P^2)$ and $F_L^gamma(x,Q^2,P^2)$ in perturbative QCD for the kinematical region $Lambda^2 ll P^2 ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe (target) photon and $Lambda$ is the QCD scale parameter. Using the framework of the operator product expansion suppleme

Maria R. D'Orsogna, Tom Chou, Tibor Antal

We solve the problem of discrete translocation of a polymer through a pore, driven by the irreversible, random sequential adsorption of particles on one side of the pore. Although the kinetics of the wall motion and the deposition are coupled, we find the exact steady-state distribution for the gap between the wall and the nearest deposited particle. This re

E. Shchukin

The relation between the boolean functions and Bell inequalities for qubits is analyzed. The connection between the maximal quantum violation of a Bell inequality and the nonlinearity of the corresponding boolean function is discussed. A visualization scheme of boolean functions is proposed. An attempt to classify Bell inequalities for qubits is made, a weak

A. R. H. Preston, S. Granville, D. H. Housden, B. Ludbrook

We investigate the electronic band structure of two of the rare-earth nitrides, DyN and SmN. Resistivity measurements imply that both materials have a semiconducting ground state, and both show resistivity anomalies coinciding with the magnetic transition, despite the different magnetic states in DyN and SmN. X-ray absorption and emission measurements are in

Dongho Chae

We are concerned on the possibility of finite time singularity in a partially viscous magnetohydrodynamic equations in $\Bbb R^n$, $n=2,3$, namely the MHD with positive viscosity and zero resistivity. In the special case of zero magnetic field the system reduces to the Navier-Stokes equations in $\Bbb R^n$. In this paper we exclude the scenario of finite tim

Jesse Fern

We examine the transformation of noise under a quantum error correcting code (QECC) concatenated repeatedly with itself, by analyzing the effects of a quantum channel after each level of concatenation using recovery operators that are optimally adapted to use error syndrome information from the previous levels of the code. We use the Shannon entropy of these

P. Sanchez-Lotero, J. J. Palacios

We calculate the critical magnetic fields for vortex expulsion for an infinitely long superconducting strip, using the Ginzburg-Landau formalism. Two critical fields can be defined associated with the disappearance of either the energetic stability or metastability of vortices in the center of the strip for decreasing magnetic fields. We compare the theoreti

Nathaniel D. Blair-Stahn, David B. Wilson

Consider a unit-resistive plate in the shape of a regular polygon with 2n sides, in which even-numbered sides are wired to electrodes and odd-numbered sides are insulated. The response matrix, or Dirichlet-to-Neumann map, allows one to compute the currents flowing through the electrodes when they are held at specified voltages. We show that the entries of th

Erhan Bayraktar, Masahiko Egami

In this paper we solve the dividend optimization problem for a corporation or a financial institution when the managers of the corporation are facing (regulatory) implementation delays. We consider several cash reservoir models for the firm including two mean-reverting processes, Ornstein-Uhlenbeck and square-root processes. We provide our solution via a new

Erhan Bayraktar, Masahiko Egami

We study a practical optimization problems for venture capital investments and/or Research and Development (R&D) investments. The first problem is that, given the amount of the initial investment and the reward function at the initial public offering (IPO) market, the venture capitalist wants to maximize overall discounted cash flows after subtracting subseq

Mark Gross, Bernd Siebert

We construct from a real affine manifold with singularities (a tropical manifold) a degeneration of Calabi-Yau manifolds. This solves a fundamental problem in mirror symmetry. Furthermore, a striking feature of our approach is that it yields an explicit and canonical order-by-order description of the degeneration via families of tropical trees. This gives co

Marcelo Samuel Berman

We find a solution for exponential inflation in Brans-Dicke cosmology endowed with a cosmological term, which includes time-varying shear and vorticity. We find that the scalar field and the scale factor increase exponentialy while shear, vorticity, energy density, cosmic pressure and the cosmological term decay exponentialy for beta < 0, where beta is defin

Andrei Faraon, Dirk Englund, Ilya Fushman, Nick Stoltz

Quantum networks based on InGaAs quantum dots embedded in photonic crystal devices rely on QDs being in resonance with each other and with the cavities they are embedded in. We developed a new technique based on temperature tuning to spectrally align different quantum dots located on the same chip. The technique allows for up to 1.8nm reversible on-chip quan

D. Gerbasi, A. S. Sanz, P. S. Christopher, M. Shapiro

Coherent control of bound state processes via the interfering overlapping resonances scenario [Christopher et al., J. Chem. Phys. 123, 064313 (2006)] is developed to control intramolecular vibrational redistribution (IVR). The approach is applied to the flow of population between bonds in a model of chaotic OCS vibrational dynamics, showing the ability to si

Gian Paolo Beretta

From the thermodynamic equilibrium properties of a two-level system with variable energy-level gap $Δ$, and a careful distinction between the Gibbs relation $dE = T dS + (E/Δ) dΔ$ and the energy balance equation $dE = δQ^\leftarrow - δW^\to$, we infer some important aspects of the second law of thermodynamics and, contrary to a recent suggestion based on the

Jacek Miekisz

Many socio-economic and biological processes can be modeled as systems of interacting individuals. The behaviour of such systems can be often described within game-theoretic models. In these lecture notes, we introduce fundamental concepts of evolutionary game theory and review basic properties of deterministic replicator dynamics and stochastic dynamics of

J. J. Lunazzi

Color encoding of depth is shown to occur naturally in images of objects observed through diffraction gratings under common white light illumination. A synthetic image is then obtained from a single point of view, a phenomenon that can be applied to stereophotography. The image can be recorded in a common color photograph, providing a simple method of visual

Li Xi, Michael D. Graham

Interior stagnation point flows of viscoelastic liquids arise in a wide variety of applications including extensional viscometry, polymer processing and microfluidics. Experimentally, these flows have long been known to exhibit instabilities, but the mechanisms underlying them have not previously been elucidated. We computationally demonstrate the existence

Yong Yu, Bogdan Danila, John A. Marsh, Kevin E. Bassler

We present a study of the application of a variant of a recently introduced heuristic algorithm for the optimization of transport routes on complex networks to the problem of finding the optimal routes of communication between nodes on wireless networks. Our algorithm iteratively balances network traffic by minimizing the maximum node betweenness on the netw

Mario J. Pinheiro

The historical roots of the word plasma are recalled. It is suggested that possibly at the beginning of the researches in low-pressure gas discharges the driving motivation was related to the psychic phenomena investigated by Sir William Crookes.

Alexander Bolonkin

Offered is a new method for saving passenger lives in any catastrofic situation, including total failure of aircraft control, extreme damage and loss aircraft wings, tail, breakdown all propelling engines, etc. It shown here that previous works which have proposed using only parachutes are useless because their proposers failed to consider the likely overloa

Juan G. Diaz Ochoa

In a co-evolutionary context, the survive probability of individual elements of a system depends on their relation with their neighbors. The natural selection process depends on the whole population, which is determined by local events between individuals. Particular characteristics assigned to each individual, as larger memory, usually improve the individua

X. Wu, H. Cao

We have measured the spectral correlations and intensity statistics of random lasing modes in weakly scattering systems, and compared them to those of the amplified spontaneous emission spikes. Their dramatic differences revealed the distinct physical mechanisms. We find that local excitation of a weakly scattering system may greatly reduce the number of las

V. Hnizdo

Heras purports to show without solving the requisite dynamic equations how the non-causal term generated by the scalar potential of the Coulomb, Kirchhoff, or velocity gauge is canceled by an equal and opposite term in the contribution to the electric field that is generated by the vector potential. Heras&#39;s procedure is criticized as being just an algebr

Peter Krizan

The paper reviews recent progress in particle identification methods. A survey of motivations and requirements for particle identification in various experimental environments is followed by the main emphasis, which is on the recent development of Cherenkov counters, from upgrades of existing devices to a novel focusing radiator concept and new photon detect

Johannes Trost, Klaus Hornberger

We present a simple model for chiral molecules which yields the frequency-dependent multipole-multipole polarizabilities required for calculating the dispersive van der Waals constants in a simple, closed, and consistent form. The model consists of a single effective charge confined to a one-dimensional wire formed by two circular arcs, which are twisted wit

V. V. Klimov, D. V. Guzatov

The proposed paradigm of plasmonic atoms and plasmonic molecules allows one to describe and predict the strongly localized plasmonic oscillations in the clusters of nanoparticles and some other nanostructures in uniform way. Strongly localized plasmonic molecules near the contacting surfaces might become the fundamental elements (by analogy with Lego bricks)

Agnes Helmstetter, Bruce E. Shaw

We study how a stress perturbation generated by a mainshock affects a population of faults obeying a rate-state friction law. Depending on the model parameters and on the initial state, the fault exhibits aftershocks, slow earthquakes, or decaying afterslip. We found several regimes with slip rate decaying as a power-law of time, with different characteristi

G. Giacomelli

The CERN to Gran Sasso Neutrino beam (CNGS) was commissioned at CERN in early August 2006 and was first sent at low intensity to Gran Sasso on August 17, 2006. The Borexino, LVD and OPERA experiments continued the commissioning of their detectors and started taking data with practically no dead time. The CNGS collected several hundred events with clean time

Aurelien Perera, Franjo Sokolic, Larisa Zoranic

Formation of microstructure in homogeneous associated liquids is analysed through the density-density pair correlation functions, both in direct and reciprocal space, as well as an effective local one-body density function. This is illustrated through a molecular dynamics study of two neat alcohols, namely methanol and \emph{tert}-butanol, which have a rich

Woodrow L. Shew, Yoann Gasteuil, Mathieu Gibert, Pascal Metz

We have developed novel instrumentation for making Lagrangian measurements of temperature in diverse fluid flows. A small neutrally buoyant capsule is equipped with on-board electronics which measure temperature and transmit the data via a wireless radio frequency link to a desktop computer. The device has 80 dB dynamic range, resolving milli-Kelvin changes

M. Dixit, D. Attie, A. Bellerive, K. Boudjemline

The International Linear Collider (ILC) Time Projection Chamber (TPC) transverse space-point resolution goal is 100 microns for all tracks including stiff 90 degree tracks with the full 2 meter drift. A Micro Pattern Gas Detector (MPGD) readout TPC can achieve the target resolution with existing techniques using 1 mm or narrower pads at the expense of increa

H. S. Köhler, S. A. Moszkowski

The relation between nuclear saturation and NN-correlations is examined. Nucleons bound in a nucleus have a reduced effective mass due to the mean field. This results in off-energy-shell scatterings modifying the free-space NN-interaction by a dispersion correction. This is a major contribution to the density-dependence of the effective in-medium force and t

Ludovic Bonneau, Philippe Quentin, Peter Moller

Systematic calculations of ground-state spin and parity of odd-mass nuclei have been performed within the Hartree--Fock--BCS (HFBCS) approach and the Finite-Range Droplet Model for nuclei for which experimental data are available. The unpaired nucleon has been treated perturbatively, and axial and left-right reflection symmetries have been assumed. As for th

O. Civitarese, M. Gadella, G. P. Pronko

In this work we present a formal solution of the extended version of the Friedrichs Model. The Hamiltonian consists of discrete and continuum bosonic states, which are coupled to fermions. The simultaneous treatment of the couplings of the fermions with the discrete and continuous sectors of the bosonic degrees of freedom leads to a system of coupled equatio

O. Civitarese, M. Gadella

In this work we present an extended version of the Friedrichs Model, which includes fermion-boson couplings. The set of fermion bound states is coupled to a boson field with discrete and continuous components. As a result of the coupling some of the fermion states may become resonant states. This feature suggests the existence of a formal link between the oc

Jessica Conway, Hermann Riecke

Multi-frequency forcing of systems undergoing a Hopf bifurcation to spatially homogeneous oscillations is investigated using a complex Ginzburg-Landau equation that systematically captures weak forcing functions that simultaneously hit the 1:1-, the 1:2-, and the 1:3-resonance. Weakly nonlinear analysis shows that generically the forcing function can be tune

G. Falkovich, S. Musacchio, L. Piterbarg, M. Vucelja

We present a model for the Lagrangian dynamics of inertial particles in a compressible flow, where fluid velocity gradients are modelled by a telegraph noise. The model allows for an analytic investigation of the role of time correlation of the flow in the aggregation-disorder transition of inertial particle. The dependence on Stokes and Kubo numbers of the

M. Asorey, P. Facchi, V. I. Man'ko, G. Marmo

The tomographic probability distribution on the phase space (cylinder) related to a circle or an interval is introduced. The explicit relations of the tomographic probability densities and the probability densities on the phase space for the particle motion on a torus are obtained and the relation of the suggested map to the Radon transform on the plane is e

Ivan Kachuryk, Anatoliy Klimyk

Physical systems with symmetries are described by functions containing kinematical and dynamical parts. We consider the case when kinematical symmetries are described by a noncompact semisimple real Lie group $G$. Then separation of kinematical parts in the functions is fulfilled by means of harmonic analysis related to the group $G$. This separation depends

M. Gadella, J. Negro, G. P. Pronko

We study the most general form of a three dimensional classical integrable system with axial symmetry and invariant under the axis reflection. We assume that the three constants of motion are the Hamiltonian, $H$, with the standard form of a kinetic part plus a potential dependent on the position only, the $z$-component of the angular momentum, $L$, and a Ha

Debashis Paul, Eric Bair, Trevor Hastie, Robert Tibshirani

We consider regression problems where the number of predictors greatly exceeds the number of observations. We propose a method for variable selection that first estimates the regression function, yielding a &#34;pre-conditioned&#34; response variable. The primary method used for this initial regression is supervised principal components. Then we apply a stan

Kyril TIntarev

The concentration compactness framework for semilinear elliptic equations without compactness, set originally by P.-L.Lions for constrained minimization in the case of homogeneous nonlinearity, is extended here to the case of general nonlinearities in the standard mountain pass setting of Ambrosetti-Rabinowitz. In these setting, existence of solutions at the

Erhan Bayraktar, Virginia R. Young

We determine the optimal investment strategy of an individual who targets a given rate of consumption and who seeks to minimize the probability of going bankrupt before she dies, also known as {\it lifetime ruin}. We impose two types of borrowing constraints: First, we do not allow the individual to borrow money to invest in the risky asset nor to sell the r

Jorge Plazas

We survey some aspects of the theory of noncommutative manifolds focusing on the noncommutative analogs of two-dimensional tori and low-dimensional spheres. We are particularly interested in those aspects of the theory that link the differential geometry and the algebraic geometry of these spaces.

Jean-Yves Audibert

We consider the learning task consisting in predicting as well as the best function in a finite reference set G up to the smallest possible additive term. If R(g) denotes the generalization error of a prediction function g, under reasonable assumptions on the loss function (typically satisfied by the least square loss when the output is bounded), it is known

Piotr B. Mucha

We investigate the global in time stability of regular solutions with large velocity vectors to the evolutionary Navier-Stokes equation in ${\bf R}^3$. The class of stable flows contains all two dimensional weak solutions. The only assumption which is required is smallness of the $L_2$-norm of initial perturbation or its derivative with respect to the `$z$&#

Rocco Chiriví, Peter Littelmann, Andrea Maffei

Let $σ$ be a simple involution of an algebraic semisimple group $G$ and let $H$ be the subgroup of $G$ of points fixed by $σ$. If the restricted root system is of type $A$, $C$ or $BC$ and $G$ is simply connected or if the restricted root system is of type $B$ and $G$ is adjoint, then we describe a standard monomial theory and the equations for the coordinat

Vincent Bosser, Federico Pellarin

This article is divided in two parts. In the first part we endow a certain ring of ``Drinfeld quasi-modular forms&#39;&#39; for $\GL_2(\FF_q[T])$ (where $q$ is a power of a prime) with a system of &#34;divided derivatives&#34; (or hyperderivations). This ring contains Drinfeld modular forms as defined by Gekeler in \cite{Ge}, and the hyperdifferential ring o

Eva Viehmann

We study the global structure of moduli spaces of quasi-isogenies of polarized p-divisible groups introduced by Rapoport and Zink. Using the corresponding results for non-polarized p-divisible groups from a previous paper, we determine their dimensions and their sets of connected components and of irreducible components.

Cristina Draper, Cándido Martín

We study group gradings on the Albert algebra and on the simple exceptional Lie algebra $\frak{f}_4$ over algebraically closed fields of characteristic zero. There are eight nontoral nonequivalent gradings on the Albert algebra (three of them being fine) and nine on $\frak{f}_4$ (also three of them fine).

Rudi Hirschfeld

For a given length and a given degree and an arbitrary partition of the positive integers, there always is a cell containing a polynomial progression of that length and that degree; moreover, the coefficients of the generating polynomial can be chosen from a given semigroup and one can prescribe the occurring powers. A multidimensional version is included.

Tore August Kro

We generalize Berger and Moerdijk&#39;s results on axiomatic homotopy theory for operads to the setting of enriched symmetric monoidal model categories, and show how this theory applies to orthogonal spectra. In particular, we provide a symmetric fibrant replacement functor for the positive stable model structure.

J. A. D. Appleby, M. Riedle

A geometric Brownian motion with delay is the solution of a stochastic differential equation where the drift and diffusion coefficient depend linearly on the past of the solution, i.e. a linear stochastic functional differential equation. In this work the asymptotic behavior in mean square of a geometric Brownian motion with delay is completely characterized

Randal Douc, Gersende Fort, Eric Moulines, Pierre Priouret

The forgetting of the initial distribution for discrete Hidden Markov Models (HMM) is addressed: a new set of conditions is proposed, to establish the forgetting property of the filter, at a polynomial and geometric rate. Both a pathwise-type convergence of the total variation distance of the filter started from two different initial distributions, and a con

Istvan Juhasz, Zoltan Szentmiklossy

All spaces below are Tychonov. We define the projective pi-character p(X) of a space X as the supremum of the values $πχ(Y)$ where Y ranges over all continuous images of X. Our main result says that every space X has a pi-base whose order is at most p(X), that is every point in X is contained in at most p(X)-many members of the pi-base. Since p(X) is at most

Erhan Bayraktar, H. Vincent Poor, Ronnie Sircar

S&P 500 index data sampled at one-minute intervals over the course of 11.5 years (January 1989- May 2000) is analyzed, and in particular the Hurst parameter over segments of stationarity (the time period over which the Hurst parameter is almost constant) is estimated. An asymptotically unbiased and efficient estimator using the log-scale spectrum is employed

Erhan Bayraktar, Masahiko Egami

In this paper, we accomplish two objectives: First, we provide a new mathematical characterization of the value function for impulse control problems with implementation delay and present a direct solution method that differs from its counterparts that use quasi-variational inequalities. Our method is direct, in the sense that we do not have to guess the for

Erhan Bayraktar, Ulrich Horst, Ronnie Sircar

One approach to the analysis of stochastic fluctuations in market prices is to model characteristics of investor behaviour and the complex interactions between market participants, with the aim of extracting consequences in the aggregate. This agent-based viewpoint in finance goes back at least to the work of Garman (1976) and shares the philosophy of statis

Erhan Bayraktar, Ulrich Horst, Ronnie Sircar

We study the effect of investor inertia on stock price fluctuations with a market microstructure model comprising many small investors who are inactive most of the time. It turns out that semi-Markov processes are tailor made for modelling inert investors. With a suitable scaling, we show that when the price is driven by the market imbalance, the log price p

Hock Peng Chan, Wei-Liem Loh

This article contains two main theoretical results on neural spike train models. The first assumes that the spike train is modeled as a counting or point process on the real line where the conditional intensity function is a product of a free firing rate function s, which depends only on the stimulus, and a recovery function r, which depends only on the time