Results for "A. Hans"

total 245114took 0.14s
Massive Modes for Quantum GraphsDec 03 2018The spectral two-point function of chaotic quantum graphs is expected to be universal. Within the supersymmetry approach, a proof of that assertion amounts to showing that the contribution of non-universal (or massive) modes vanishes in the limit of infinite ... More
The Layzer-Irvine Equation for Scalar-Tensor Theories: A Test of Modified Gravity N-body SimulationsAug 21 2013The Layzer-Irvine equation describes energy conservation for a pressure less fluid interacting though quasi-Newtonian gravity in an expanding Universe. We here derive a Layzer-Irvine equation for scalar field theories where the scalar field is coupled ... More
Robustness of shape-restricted regression estimators: an envelope perspectiveMay 07 2018Classical least squares estimators are well-known to be robust with respect to moment assumptions concerning the error distribution in a wide variety of finite-dimensional statistical problems; generally only a second moment assumption is required for ... More
Very Short Term Time-Series Forecasting of Solar Irradiance Without Exogenous InputsOct 13 2018Jul 29 2019This paper compares different forecasting methods and models to predict average values of solar irradiance with a sampling time of 15 min over a prediction horizon of up to 3 h. The methods considered only require historic solar irradiance values, the ... More
Nuclear Level Densities in the Constant-Spacing ModelJun 07 2012Jan 07 2013A new method to calculate level densities for non-interacting Fermions within the constant-spacing model with a finite number of states is developed. We show that asymptotically (for large numbers of particles or holes) the densities have Gaussian form. ... More
Deep Quantum Geometry of MatricesJun 20 2019We employ machine learning techniques to provide accurate variational wavefunctions for matrix quantum mechanics, with multiple bosonic and fermionic matrices. Variational quantum Monte Carlo is implemented with deep generative flows to search for gauge ... More
Multivariate convex regression: global risk bounds and adaptationJan 25 2016We study the problem of estimating a multivariate convex function defined on a convex body in a regression setting with random design. We are interested in optimal rates of convergence under a squared global continuous $l_2$ loss in the multivariate setting ... More
On helicity and spin on the light coneNov 21 2001Starting from a one-body front-form equation with Lepage-Brodsky spinors we show, with a fair amount of new technology, how an integral equation in standard momentum space with Bjorken-Drell spinors can be obtained. The integral equation decouples for ... More
Two Interacting Electrons in a Disorder Potential: Localization PropertiesDec 10 2002Two electrons move in a quasi one--dimensional wire under the influence of a short--range interaction. We restrict Hilbert space to those states where the two electrons are close to each other. Using supersymmetry, we present a complete analytical solution ... More
Localization Properties of Two Interacting Electrons in a Disordered Quasi One-Dimensional PotentialJun 26 2002We study the transport properties of two electrons in a quasi one-dimensional disordered wire. The electrons are subject to both, a disorder potential and a short range two-body interaction. Using the approach developed by Iida et al. [ Ann. Phys. (N.Y.) ... More
Low-Temperature Expansions and Correlation Functions of the Z_3-Chiral Potts ModelApr 20 1993Using perturbative methods we derive new results for the spectrum and correlation functions of the general Z_3-chiral Potts quantum chain in the massive low-temperature phase. Explicit calculations of the ground state energy and the first excitations ... More
Locality Bound for Dissipative Quantum TransportJun 05 2018Oct 05 2018We prove an upper bound on the diffusivity of a general local and translation invariant quantum Markovian spin system: $D \leq D_0 + \left(\alpha \, v_\text{LR} \tau + \beta \, \xi \right) v_\text{C}$. Here $v_\text{LR}$ is the Lieb-Robinson velocity, ... More
Large coupling asymptotics for the Lyapunov exponent of quasi-periodic Schrödinger operators with analytic potentialsDec 13 2016Nov 08 2017We quantify the coupling asymptotics for the Lyapunov-exponent of a one-frequency quasi-periodic Schr\"odinger operator with analytic potential sampling function. The result refines the well-known lower bound of the Lyapunov-exponent by Sorets and Spencer. ... More
Formal Concept Analysis of Rodent Carriers of Zoonotic DiseaseAug 25 2016The technique of Formal Concept Analysis is applied to a dataset describing the traits of rodents, with the goal of identifying zoonotic disease carriers,or those species carrying infections that can spillover to cause human disease. The concepts identified ... More
A Random Matrix Study of the QCD Sign ProblemMay 14 2008We investigate the severity of the sign problem in a random matrix model for QCD at finite temperature T and baryon chemical potential mu. We obtain analytic expression for the average phase factor -- the measure of the severity of the sign problem at ... More
Deformation theory of scalar-flat Kähler ALE surfacesMay 17 2016Sep 14 2018We prove a Kuranishi-type theorem for deformations of complex structures on ALE K\"ahler surfaces. This is used to prove that for any scalar-flat K\"ahler ALE surface, all small deformations of complex structure also admit scalar-flat K\"ahler ALE metrics. ... More
Digit expansions of numbers in different basesMay 02 2019A folklore conjecture in number theory states that the only integers whose expansions in base $3,4$ and $5$ contain only binary digits are $0, 1$ and $82000$. In this paper we present the first significant progress on this conjecture. Furthermore, we ... More
Universality of quantum Brownian motionNov 02 1998Are Markovian master equations for quantum Brownian motion independent of model assumptions used in the derivation and, thus, universal? With the aim of answering this question, we use a random band-matrix model for the system-bath interaction to derive ... More
Convergence rates of least squares regression estimators with heavy-tailed errorsJun 07 2017Jul 15 2018We study the performance of the Least Squares Estimator (LSE) in a general nonparametric regression model, when the errors are independent of the covariates but may only have a $p$-th moment ($p\geq 1$). In such a heavy-tailed regression setting, we show ... More
Nuclear Level Densities at High Excitation Energies and for Large Particle NumbersJul 01 2013Sep 27 2013Starting from an independent-particle model with a finite and arbitrary set of single-particle energies, we develop an analytical approximation to the many-body level density $\rho_A(E)$ and to particle-hole densities. We use exact expressions for the ... More
Local moduli of scalar-flat Kähler ALE surfacesSep 19 2018In this article, we give a survey of our construction of a local moduli space of scalar-flat K\"ahler ALE metrics in complex dimension $2$. We also prove an explicit formula for the dimension of this moduli space on a scalar-flat K\"ahler ALE surface ... More
Complex sampling designs: uniform limit theorems and applicationsMay 30 2019In this paper, we develop a general approach to proving global and local uniform limit theorems for the Horvitz-Thompson empirical process arising from complex sampling designs. Global theorems such as Glivenko-Cantelli and Donsker theorems, and local ... More
Predicting Novel Tick Vectors of Zoonotic DiseaseJun 20 2016With the resurgence of tick-borne diseases such as Lyme disease and the emergence of new pathogens such as Powassan virus, understanding what distinguishes vector from non-vector species, and predicting undiscovered tick vectors is an important step towards ... More
Approximations of convex bodies by measure-generated setsJun 21 2017Given a Borel measure $\mu$ on ${\mathbb R}^{n}$, we define a convex set by \[ M({\mu})=\bigcup_{\substack{0\le f\le1,\\ \int_{{\mathbb R}^{n}}f\,{\rm d}{\mu}=1 } }\left\{ \int_{{\mathbb R}^{n}}yf\left(y\right)\,{\rm d}{\mu}\left(y\right)\right\} , \] ... More
Existence and compactness theory for ALE scalar-flat Kähler surfacesJan 17 2019Apr 19 2019Our main result in this article is a compactness result which states that a noncollapsed sequence of asymptotically locally Euclidean (ALE) scalar-flat K\"ahler metrics on a minimal K\"ahler surface whose K\"ahler classes stay in a compact subset of the ... More
Approximation and Estimation of s-Concave Densities via Rényi DivergencesMay 02 2015Oct 22 2015In this paper, we study the approximation and estimation of $s$-concave densities via R\'enyi divergence. We first show that the approximation of a probability measure $Q$ by an $s$-concave densities exists and is unique via the procedure of minimizing ... More
Study of Anomalous Couplings at a $500$~GeV $e^+e^-$ Linear Collider with Polarized BeamsNov 11 1995We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at a future $500$~GeV $e^+ e^-$ linear collider. We concentrate on the case in which the electroweak symmetry breaking sector is strongly interacting ... More
Does localization occur in a hierarchical random-matrix model for many-body states?Mar 24 2000We use random-matrix theory and supersymmetry techniques to work out the two-point correlation function between states in a hierarchical model which employs Feshbach's chaining hypothesis: Classes of many-body states are introduced. Only states within ... More
Constructing solutions of Hamilton-Jacobi equations for 2 D fields with one component by means of Baecklund transformationsFeb 01 1995Feb 03 1995The Hamilton-Jacobi formalism generalized to 2-dimensional field theories according to Lepage's canonical framework is applied to several relativistic real scalar fields, e.g. massless and massive Klein-Gordon, Sinh and Sine-Gordon, Liouville and $\phi^4$ ... More
Solutions of the Hamilton--Jacobi equation for one component two dimensional Field TheoriesJan 25 1995The Hamilton--Jacobi formalism generalized to 2--dimensional field theories according to Lepage's canonical framework is applied to several covariant real scalar fields, e.g. massless and massive Klein--Gordon, Sine--Gordon, Liouville and $\phi^4$ theories. ... More
Geometry of the 3-Qubit State, Entanglement and Division AlgebrasFeb 11 2003Mar 13 2004We present a generalization to 3-qubits of the standard Bloch sphere representation for a single qubit and of the 7-dimensional sphere representation for 2 qubits presented in Mosseri {\it et al.}\cite{Mosseri2001}. The Hilbert space of the 3-qubit system ... More
Spontaneous Emergence of Spatio-Temporal Order in Class 4 AutomataApr 30 2005We report surprisingly regular behaviors observed for a class 4 cellular automaton, the totalistic rule 20: starting from disordered initial configurations the automaton produces patterns which are periodic not only in time but also in space. This is ... More
A Fast Route to Non-Linear Clustering Statistics in Modified Gravity TheoriesMar 25 2014Jun 19 2015We propose a simple and computationally fast method for performing N-body simulations for a large class of modified gravity theories with a screening mechanism such as chameleons, symmetrons and galileons. By combining the linear Klein-Gordon equation ... More
Quenched Kosterlitz-Thouless Superfluid TransitionsOct 05 1999The properties of rapidly quenched superfluid phase transitions are computed for two-dimensional Kosterlitz-Thouless (KT) systems. The decay in the vortex-pair density and the recovery of the superfluid density after a quench are found by solving the ... More
Isomorphism classes and automorphisms of finite Hopf algebras of type A_nNov 10 2005Feb 19 2007In our previous paper math/0502157 we classified a large class of finite-dimensional pointed Hopf algebras up to isomorphism. However the following problem was left open for Hopf algebras of of type $A,D$ or $E_6$, that is whose Cartan matrix is connected ... More
Exterior mass estimates and $L^2$ restriction bounds for Neumann data along hypersurfacesMar 18 2013Nov 08 2013We study the problem of estimating the $L^2$ norm of Laplace eigenfunctions on a compact Riemannian manifold $M$ when restricted to a hypersurface $H$. We prove mass estimates for the restrictions of eigenfunctions $\phi_h$, $(h^2 \Delta - 1)\phi_h = ... More
Assessing non-linear models for galaxy clustering III: Theoretical accuracy for Stage IV surveysMay 13 2019We provide in depth MCMC comparisons of two different models for the halo redshift space power spectrum, namely a variant of the commonly applied Taruya-Nishimichi-Saito (TNS) model and an effective field theory of large scale structure (EFTofLSS) inspired ... More
Reworking the Tucson-Melbourne Three-Nucleon PotentialDec 30 2000We introduce new values of the strength constants (i.e., $a$, $b$, $c$, and $d$ coefficients) of the Tucson-Melbourne (TM) 2$\pi$ exchange three nucleon potential. The new values come from contemporary dispersion relation analyses of meson factory $\pi$N ... More
Microscopic Model for Granular Stratification and SegregationSep 30 1998We study segregation and stratification of mixtures of grains differing in size, shape and material properties poured in two-dimensional silos using a microscopic lattice model for surface flows of grains. The model incorporates the dissipation of energy ... More
About Entropy and Thermalization - a Miniworkshop PerspectiveSep 07 1994We present a summary and perspective view of the Miniworkshop on ``{\it Entropy and Thermalization}'' in strong interactions (convener J. Rafelski), which was part of the NATO Advanced Research Workshop on ``{\it Hot Hadronic Matter}'' that took place ... More
Determination of sparticle masses and SUSY parametersOct 20 1999A case study will be presented to determine the particle masses and parameters of a specific mSUGRA model at the TESLA Linear Collider with high precision.
An embedded circumnuclear disk in Mrk 273May 06 2004Radio observations using very long baseline interferometry (VLBI) and the Westerbork interferometer have been carried out to study the hydroxyl Megamaser emission in Mrk~273 at different spatial resolutions. Line and continuum observations were carried ... More
Temperature statistics above a deep-ocean sloping boundaryApr 02 2015Jun 04 2015We present a detailed analysis of the temperature statistics in an oceanographic observational dataset. The data are collected using a moored array of thermistors, 100 m tall and starting 5 m above the bottom, deployed during four months above the slopes ... More
Non-Universal Behavior of the k-Body Embedded Gaussian Unitary Ensemble of Random MatricesOct 26 2000May 17 2001Using a novel approach, we investigate the shape of the average spectrum and the spectral fluctuations of the $k$-body embedded unitary ensemble in the limit of large matrix dimension. We identify the transition point between semicircle and Gaussian shape. ... More
User interfaces for computational science: a domain specific language for OOMMF embedded in PythonSep 23 2016Feb 24 2017Computer simulations are used widely across the engineering and science disciplines, including in the research and development of magnetic devices using computational micromagnetics. In this work, we identify and review different approaches to configuring ... More
Watersheds and Explosive percolationMar 03 2011The recent work by Achlioptas, D'Souza, and Spencer opened up the possibility of obtaining a discontinuous (explosive) percolation transition by changing the stochastic rule of bond occupation. Despite the active research on this subject, several questions ... More
The Helstrom measurement: A nondestructive implementationOct 25 2017We discuss a novel implementation of the minimum error state discrimination measurement, originally introduced by Helstrom. In this implementation, instead of performing the optimal projective measurement directly on the system, it is first entangled ... More
Advances in the Design and Implementation of a Multi-Tier Architecture in the GIPSY EnvironmentJun 26 2009We present advances in the software engineering design and implementation of the multi-tier run-time system for the General Intensional Programming System (GIPSY) by further unifying the distributed technologies used to implement the Demand Migration ... More
On Molecular Hydrogen Formation and the Magnetohydrostatic Equilibrium of SunspotsOct 04 2011Oct 06 2011We have investigated the problem of sunspot magnetohydrostatic equilibrium with comprehensive IR sunspot magnetic field survey observations of the highly sensitive Fe I lines at 15650 \AA\ and nearby OH lines. We have found that some sunspots show isothermal ... More
Some remarks on "Convergence of Picard's iteration using projection algorithm for noncyclic contractions" [Indag. Math. 30 (2019) 227--239]Jul 02 2019In this note, at first we prove that the existence of best proximity points for cyclic relatively nonexpansive mappings is equivalent to the existence of best proximity pairs for noncyclic relatively nonexpansive mappings in the setting of strictly convex ... More
The Vainshtein mechanism beyond the quasi-static approximationMay 13 2015Theories of modified gravity, in both the linear and fully non-linear regime, are often studied under the assumption that the evolution of the new (often scalar) degree of freedom present in the theory is quasi-static. This approximation significantly ... More
Near optimal discrimination of binary coherent signals via atom-light interactionOct 12 2017Apr 19 2018We study the discrimination of weak coherent states of light with significant overlaps by nondestructive measurements on the light states through measuring atomic states that are entangled to the coherent states via dipole coupling. In this way, the problem ... More
Aspects of quantum coherence in the optical Bloch equationsApr 12 2006Aspects of coherence and decoherence are analyzed within the optical Bloch equations. By rewriting the analytic solution in an alternate form, we are able to emphasize a number of unusual features: (a) despite the Markovian nature of the bath, coherence ... More
Tidally enhanced stellar wind: a way to make the symbiotic channel to Type Ia supernova viableJun 07 2011In the symbiotic (or WD+RG) channel of the single degenerate scenario for type Ia supernovae (SNe Ia) the explosions occur a relatively long time after star formation. The birthrate from this channel would be too low to account for all observed SNe Ia ... More
Zero Dynamics for Port-Hamiltonian SystemsNov 19 2017The zero dynamics of infinite-dimensional systems can be difficult to characterize. The zero dynamics of boundary control systems are particularly problematic. In this paper the zero dynamics of port-Hamiltonian systems are studied. A complete characterization ... More
A Counterexample to the Vector Generalization of Costa's EPI, and Partial ResolutionApr 20 2017We give a counterexample to the vector generalization of Costa's entropy power inequality (EPI) due to Liu, Liu, Poor and Shamai. In particular, the claimed inequality can fail if the matix-valued parameter in the convex combination does not commute with ... More
Observational evidence for a local underdensity in the Universe and its effect on the measurement of the Hubble ConstantJul 29 2019For precision cosmological studies it is important to know the local properties of our reference point from which we observe the Universe. In particular for the determination of the Hubble constant with low redshift distance indicators, the values observed ... More
Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after RosettaAug 12 2019In situ research on cometary chemistry began when measurements from the Giotto mission at comet 1P/Halley revealed the presence of complex organics in the coma. New telescopes and space missions have provided detailed remote and in situ measurements of ... More
Cosmology of Chameleons with Power-Law CouplingsOct 27 2010Mar 15 2011In chameleon field theories a scalar field can couple to matter with gravitational strength and still evade local gravity constraints due to a combination of self-interactions and the couplings to matter. Originally, these theories were proposed with ... More
Estimates of the temperature flux-temperature gradient relation above a sea-floorFeb 08 2016The relation between the flux of temperature (or buoyancy), the vertical temperature gradient and the height above the bottom, is investigated in an oceanographic context, using high-resolution temperature measurements. The model for the evolution of ... More
Rigorous spatial statistics for gaze patterns in scene viewing: Effects of repeated viewingApr 06 2017Scene viewing is used to study attentional selection in complex but still controlled environments. One of the main observations on eye movements during scene viewing is the inhomogeneous distribution of fixation locations: While some parts of an image ... More
Estimates of cluster masses in screened modified gravitySep 09 2016Dec 20 2016We use cosmological hydrodynamical simulations to study the effect of screened modified gravity models on the mass estimates of galaxy clusters. In particular, we focus on two novel aspects: (i) we study modified gravity models in which baryons and dark ... More
Investigation of the obscuring circumnuclear torus in the active galaxy Mrk231Feb 19 2003Here we report on observations of powerful hydroxyl (OH) line emissions that trace the obscuring material within the circumnuclear environment of the galaxy Markarian 231. The hydroxyl (mega)-maser emission shows the characteristics of a rotating, dusty, ... More
Enhanced Spin Conductance of a Thin-Film Insulating AntiferromagnetFeb 03 2017Nov 02 2018We investigate spin transport by thermally excited spin waves in an antiferromagnetic insulator. Starting from a stochastic Landau-Lifshitz-Gilbert phenomenology, we obtain the out-of-equilibrium spin-wave properties. In linear response to spin biasing ... More
The bicompletion of the Hausdorff quasi-uniformitySep 29 2008We study conditions under which the Hausdorff quasi-uniformity ${\mathcal U}_H$ of a quasi-uniform space $(X,{\mathcal U})$ on the set ${\mathcal P}_0(X)$ of the nonempty subsets of $X$ is bicomplete. Indeed we present an explicit method to construct ... More
Using Drell-Yan $A_{FB}$ to constrain PDFsJul 17 2015We show that measurements of the forward-backward charge asymmetry ($A_{FB}(M,y)$) of Drell-Yan dilepton events produced at hadron colliders provide a new powerful tool to constrain Parton Distribution Functions (PDFs). PDF uncertainties are the dominant ... More
Spatial statistics and attentional dynamics in scene viewingMay 13 2014Dec 04 2014In humans and in foveated animals visual acuity is highly concentrated at the center of gaze, so that choosing where to look next is an important example of online, rapid decision making. Computational neuroscientists have developed biologically-inspired ... More
Diffusion of single ellipsoids under quasi-2D confinementsMar 07 2009We report video-microscopy measurements of the translational and rotational Brownian motions of isolated ellipsoidal particles in quasi-two-dimensional sample cells of increasing thickness. The long-time diffusion coefficients were measured along the ... More
Spatial statistics for gaze patterns in scene viewing: Effects of repeated viewingApr 06 2017Nov 13 2018Scene viewing is used to study attentional selection in complex but still controlled environments. One of the main observations on eye movements during scene viewing is the inhomogeneous distribution of fixation locations: While some parts of an image ... More
Using Drell-Yan forward-backward asymmetry to reduce PDF uncertainties in the measurement of electroweak parametersJul 09 2015Feb 20 2016The uncertainties in Parton Distribution Functions (PDFs) are the dominant source of the systematic uncertainty in precision measurements of electroweak parameters at hadron colliders (e.g. $\sin^2\theta_{eff}(M_Z)$, $\sin^2\theta_{W}=1-M_W^2/M_Z^2$ and ... More
Two-Stage Consensus-Based Distributed MPC for Interconnected MicrogridsOct 08 2018In this paper, we propose a model predictive control based two-stage energy management system that aims at increasing the renewable infeed in interconnected microgrids (MGs). In particular, the proposed approach ensures that each MG in the network benefits ... More
Atomic Calligraphy: The Direct Writing of Nanoscale Structures using MEMSApr 04 2013We present a micro-electromechanical system (MEMS) based method for the resist free patterning of nano-structures. Using a focused ion beam (FIB) to customize larger MEMS machines, we fabricate apertures as small as 50 nm on plates that can be moved with ... More
End-to-end Symmetry Preserving Inter-atomic Potential Energy Model for Finite and Extended SystemsMay 23 2018Dec 20 2018Machine learning models are changing the paradigm of molecular modeling, which is a fundamental tool for material science, chemistry, and computational biology. Of particular interest is the inter-atomic potential energy surface (PES). Here we develop ... More
The Inflatino Problem in Supergravity Inflationary ModelsJul 19 2001We consider the potential problems due to the production of inflatinos and gravitinos after inflation. Inflationary models with a single scale set by the microwave background anisotropies have a low enough reheat temperature to avoid problems with the ... More
No-boundary wave function for two-field inflationApr 10 2014May 07 2015In this paper, we investigate the no-boundary wave function and the complex-valued instantons for two-field inflation models that have different masses. If there is a relatively massive direction, to classicalize the massive field, the solution should ... More
Reliability of structural systems subjected to extreme forcing eventsOct 19 2016Oct 20 2016We characterize the complex, heavy-tailed probability distribution functions (pdf) describing the response and its local extrema for structural systems subjected to random forcing that includes extreme events. Our approach is based on the recent probabilistic ... More
How individuals learn to take turns: Emergence of alternating cooperation in a congestion game and the prisoner's dilemmaApr 26 2005In many social dilemmas, individuals tend to generate a situation with low payoffs instead of a system optimum ("tragedy of the commons"). Is the routing of traffic a similar problem? In order to address this question, we present experimental results ... More
At What Frequency Should the Kelly Bettor Bet?Jan 20 2018We study the problem of optimizing the betting frequency in a dynamic game setting using Kelly's celebrated expected logarithmic growth criterion as the performance metric. The game is defined by a sequence of bets with independent and identically distributed ... More
Number-conserving interacting fermion models with exact topological superconducting ground statesMar 03 2017We present a method to construct number-conserving Hamiltonians whose ground states exactly reproduce an arbitrarily chosen BCS-type mean-field state. Such parent Hamiltonians can be constructed not only for the usual $s$-wave BCS state, but also for ... More
Transmission phase of a quantum dot: Testing the role of population switchingSep 24 2008We propose a controlled experiment to clarify the physical mechanism causing phase lapses of the amplitude for electron transmission through nanoscale devices. Such lapses are generically observed in valleys between adjacent Coulomb--blockade peaks. The ... More
Consideration of Thermal Hall Effect in Undoped CupratesMar 04 2019A recent observation of thermal Hall effect of magnetic origin in underdoped cuprates calls for critical re-examination of low-energy magnetic dynamics in undoped antiferromagnetic compound on square lattice, where traditional, renormalized spin-wave ... More
On the reliability of mass-loss-rate estimates for AGB starsJun 03 2008In the recent literature there has been some doubt as to the reliability of CO multi-transitional line observations as a mass-loss-rate estimator for AGB stars. Mass-loss rates for 10 intermediate- to high-mass-loss-rate AGB stars are derived using a ... More
Truncations of Random Orthogonal MatricesAug 12 2010Oct 20 2010Statistical properties of non--symmetric real random matrices of size $M$, obtained as truncations of random orthogonal $N\times N$ matrices are investigated. We derive an exact formula for the density of eigenvalues which consists of two components: ... More
Renormalized analytic solution for the enstrophy cascade in two-dimensional quantum turbulenceJun 18 2019The forward enstrophy cascade in two-dimensional quantum turbulence in a superfluid film connected to a thermal bath is investigated using a Fokker-Planck equation based on Kosterlitz-Thouless renormalization. The steady-state cascade is formed by injecting ... More
Universal predictions of screened modified gravity on cluster scalesMay 26 2015Oct 12 2015Modified gravity models require a screening mechanism to be able to evade the stringent constraints from local gravity experiments and, at the same time, give rise to observable astrophysical and cosmological signatures. Such screened modified gravity ... More
At What Frequency Should the Kelly Bettor Bet?Jan 20 2018Aug 21 2018We study the problem of optimizing the betting frequency in a dynamic game setting using Kelly's celebrated expected logarithmic growth criterion as the performance metric. The game is defined by a sequence of bets with independent and identically distributed ... More
A Binary Model for the UV-upturn of Elliptical GalaxiesMar 15 2007The discovery of an excess of light in the far-ultraviolet (UV) in 1969 in elliptical galaxies was a major surprise. While it is now clear that this UV excess (UV-upturn) is probably caused by an old population of helium-burning stars. Han et al (2002, ... More
Correlations of conductance peaks and transmission phases in deformed quantum dotsJul 21 1998We investigate the Coulomb blockade resonances and the phase of the transmission amplitude of a deformed ballistic quantum dot weakly coupled to leads. We show that preferred single--particle levels exist which stay close to the Fermi energy for a wide ... More
The Electronic States of a Double Carbon Vacancy Defect in Pyrene: A Model Study for GrapheneNov 07 2016The electronic states occurring in a double vacancy defect for graphene nanoribbons have been calculated in detail based on a pyrene model. Extended ab initio calculations using the MR configuration interaction (MRCI) method have been performed to describe ... More
Artificial spin-orbit coupling in ultra-cold Fermi superfluidsOct 28 2011We develop a theory for interacting fermions in the presence of spin-orbit coupling and Zeeman fields, and show that many new superfluids phases, which are topological in nature, emerge. Depending on values of spin-orbit coupling, Zeeman fields, and interactions, ... More
The evolution from BCS to BEC superfluidity in the presence of disorderDec 10 2010We describe the effects of disorder on the critical temperature of $s$-wave superfluids from the BCS to the BEC regime, with direct application to ultracold fermions. We use the functional integral method and the replica technique to study Gaussian correlated ... More
Topological phase transitions in ultra-cold Fermi superfluids: the evolution from BCS to BEC under artificial spin-orbit fieldsAug 19 2011Aug 23 2011We discuss topological phase transitions in ultra-cold Fermi superfluids induced by interactions and artificial spin orbit fields. We construct the phase diagram for population imbalanced systems at zero and finite temperatures, and analyze spectroscopic ... More
Edwards Statistical Mechanics for Jammed Granular MatterFeb 13 2016Oct 05 2017In 1989, Sir Sam Edwards made the visionary proposition to treat jammed granular materials using a volume ensemble of equiprobable jammed states in analogy to thermal equilibrium statistical mechanics, despite their inherent athermal features. Since then, ... More
Conductivity of Coniglio-Klein clustersJul 17 2012Dec 04 2012We performed numerical simulations of the $q$-state Potts model to compute the reduced conductivity exponent $t/ \nu$ for the critical Coniglio-Klein clusters in two dimensions, for values of $q$ in the range $[1;4]$. At criticality, at least for $q<4$, ... More
Efficient algorithm to study interconnected networksJan 14 2013Interconnected networks have been shown to be much more vulnerable to random and targeted failures than isolated ones, raising several interesting questions regarding the identification and mitigation of their risk. The paradigm to address these questions ... More
Low and intermediate-mass close binary evolution and the initial - final mass relationOct 13 2000Using Eggleton's stellar evolution code, we carry out 150 runs of Pop I binary evolution calculations, with the initial primary mass between 1 and 8 solar masses the initial mass ratio between 1.1 and 4, and the onset of Roche lobe overflow (RLOF) at ... More
A Topological Framework for Local Structure Analysis in Condensed MatterAug 24 2015Physical systems are frequently modeled as sets of points in space, each representing the position of an atom, molecule, or mesoscale particle. As many properties of such systems depend on the underlying ordering of their constituent particles, understanding ... More
Determination of Trace Moisture Content in Dimethylacetamide by Gas ChromatographyJan 08 2018Dimethylacetamide is used as a solvent in polymer processing and moisture in DMA affects the morphology and mechanical properties of the polymer products. This paper describes a method for determination of trace moisture content in DMA by acetylene production ... More
The Integer Valued SU(3) Casson Invariant for Brieskorn spheresNov 11 2003We develop techniques for computing the integer valued SU(3) Casson invariant. Our method involves resolving the singularities in the flat moduli space using a twisting perturbation and analyzing its effect on the topology of the perturbed flat moduli ... More
An integer valued SU(3) Casson invariantAug 11 2000We define an integer valued invariant of homology spheres using the methods of SU(3) gauge theory and study its behavior under orientation reversal and connected sum.