Results for "Mark Daley"

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Novelty Search for Deep Reinforcement Learning Policy Network Weights by Action Sequence Edit Metric DistanceFeb 08 2019Reinforcement learning (RL) problems often feature deceptive local optima, and learning methods that optimize purely for reward signal often fail to learn strategies for overcoming them. Deep neuroevolution and novelty search have been proposed as effective ... More
On the Shuffle Automaton Size for WordsJul 29 2009We investigate the state size of DFAs accepting the shuffle of two words. We provide words u and v, such that the minimal DFA for u shuffled with v requires an exponential number of states. We also show some conditions for the words u and v which ensure ... More
The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical StructureMar 29 2019Apr 08 2019The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and Neptune analogs. ... More
From Helmut Jürgensen's Former Students: The Game of Informatics ResearchMar 07 2019Personal reflections are given on being students of Helmut J\"urgensen. Then, we attempt to address his hypothesis that informatics follows trend-like behaviours through the use of a content analysis of university job advertisements, and then via simulation ... More
On the Generalizability of Linear and Non-Linear Region of Interest-Based Multivariate Regression Models for fMRI DataFeb 03 2018In contrast to conventional, univariate analysis, various types of multivariate analysis have been applied to functional magnetic resonance imaging (fMRI) data. In this paper, we compare two contemporary approaches for multivariate regression on task-based ... More
Insights into Quasar UV Spectra Using Unsupervised Clustering AnalysisMar 10 2016Machine learning can provide powerful tools to detect patterns in multi-dimensional parameter space. We use K-means -a simple yet powerful unsupervised clustering algorithm which picks out structure in unlabeled data- to study a sample of quasar UV spectra ... More
Two lilypond systems of finite line-segmentsMay 31 2014The paper discusses two models for non-overlapping finite line-segments constructed via the lilypond protocol, operating here on a given array of points in the plane with which are associated directions. At time 0, each line-segment starts growing at ... More
Particle statistics and lossy dynamics of ultracold atoms in optical latticesSep 11 2017Experimental control over ultracold quantum gases has made it possible to investigate low-dimensional systems of both bosonic and fermionic atoms. In closed 1D systems there are a lot of similarities in the dynamics of local quantities for spinless fermions ... More
Floquet engineering of correlated tunneling in the Bose-Hubbard model with ultracold atomsFeb 08 2016May 18 2016We report on the experimental implementation of tunable occupation-dependent tunneling in a Bose-Hubbard system of ultracold atoms via time-periodic modulation of the on-site interaction energy. The tunneling rate is inferred from a time-resolved measurement ... More
Dynamics of many-body localization in the presence of particle lossJun 02 2017At long times residual couplings to the environment become relevant even in the most isolated experiments, creating a crucial difficulty for the study of fundamental aspects of many-body dynamics. A particular example is many-body localization in a cold-atom ... More
Precision Measurements on a Tunable Mott Insulator of Ultracold AtomsJul 09 2011We perform precision measurements on a Mott-insulator quantum state of ultracold atoms with tunable interactions. We probe the dependence of the superfluid-to-Mott-insulator transition on the interaction strength and explore the limits of the standard ... More
Controlling Quantum Transport via Dissipation EngineeringApr 07 2019Inspired by the microscopic control over dissipative processes in quantum optics and cold atoms, we develop an open-system framework to study dissipative control of transport in quantum dot systems with strongly interacting fermions, relevant for both ... More
Measurement and feedback for cooling heavy levitated particles in low frequency trapsMar 25 2019We consider a possible route to ground state cooling of a levitated nanoparticle, magnetically trapped by a strong permanent magnet, using a combination of measurement and feedback. The trap frequency of this system is much lower than those involving ... More
Interference of interacting matter wavesDec 28 2008The phenomenon of matter wave interference lies at the heart of quantum physics. It has been observed in various contexts in the limit of non-interacting particles as a single particle effect. Here we observe and control matter wave interference whose ... More
Observation of many-body long-range tunneling after a quantum quenchDec 10 2013Quantum tunneling constitutes one of the most fundamental processes in nature. We observe resonantly-enhanced long-range quantum tunneling in one-dimensional Mott-insulating Hubbard chains that are suddenly quenched into a tilted configuration. Higher-order ... More
Quantum quench in an atomic one-dimensional Ising chainApr 09 2013Jul 18 2013We study non-equilibrium dynamics for an ensemble of tilted one-dimensional atomic Bose-Hubbard chains after a sudden quench to the vicinity of the transition point of the Ising paramagnetic to anti-ferromagnetic quantum phase transition. The quench results ... More
Quantum trajectories and open many-body quantum systemsMay 26 2014The study of open quantum systems has become increasingly important in the past years, as the ability to control quantum coherence on a single particle level has been developed in a wide variety of physical systems. In quantum optics, the study of open ... More
Persistence of energy-dependent localization in the Anderson-Hubbard model with increasing system size and dopingJan 12 2016Non-interacting systems with bounded disorder have been shown to exhibit sharp density of states peaks at the band edge which coincide with an energy range of abruptly suppressed localization. Recent work has shown that these features also occur in the ... More
Quantum Computing and Quantum Simulation with Group-II AtomsJun 28 2011Recent experimental progress in controlling neutral group-II atoms for optical clocks, and in the production of degenerate gases with group-II atoms has given rise to novel opportunities to address challenges in quantum computing and quantum simulation. ... More
Signatures of Many-Body Localization in a Controlled Open Quantum SystemOct 05 2016In the presence of disorder, an interacting closed quantum system can undergo many-body localization (MBL) and fail to thermalize. However, over long times even weak couplings to any thermal environment will necessarily thermalize the system and erase ... More
Efficient Eligibility Traces for Deep Reinforcement LearningOct 23 2018Eligibility traces are an effective technique to accelerate reinforcement learning by smoothly assigning credit to recently visited states. However, their online implementation is incompatible with modern deep reinforcement learning algorithms, which ... More
Preparation and spectroscopy of a metastable Mott insulator state with attractive interactionsJan 04 2012We prepare and study a metastable attractive Mott insulator state formed with bosonic atoms in a three-dimensional optical lattice. Starting from a Mott insulator with Cs atoms at weak repulsive interactions, we use a magnetic Feshbach resonance to tune ... More
The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical StructureMar 29 2019The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and Neptune analogs. ... More
Interacting Fields and Flows: Magnetic Hot JupitersNov 30 2017We present Magnetohydrodynamic (MHD) simulations of the magnetic interactions between a solar type star and short period hot Jupiter exoplanets, using the publicly available MHD code PLUTO. It has been predicted that emission due to magnetic interactions ... More
Effective three-body interactions via photon-assisted tunneling in an optical latticeNov 07 2013We present a simple, experimentally realizable method to make coherent three-body interactions dominate the physics of an ultracold lattice gas. Our scheme employs either lattice modulation or laser-induced tunneling to reduce or turn off two-body interactions ... More
Winds of Massive Magnetic Stars: Interacting Fields and FlowNov 30 2017We present results of 3D numerical simulations of magnetically confined, radiatively driven stellar winds of massive stars, conducted using the astrophysical MHD code Pluto, with a focus on understanding the rotational variability of radio and sub-mm ... More
What's the value in more moments?May 11 2016The moment-based non-parametric species richness estimator of Chao is one of the most widely used estimators for the number of unobserved species in a sampling experiment. This is due in large part to its simplicity and robustness. This simplicity can ... More
A martingale view of Blackwell's renewal theorem and its extensions to a general counting processDec 18 2017Dec 24 2018Martingales constitute a basic tool in stochastic analysis; this paper considers their application to counting processes. We use this tool to revisit a renewal theorem and its extensions for various counting processes. We first consider a renewal process ... More
Extreme scattering events and Galactic dark matterFeb 10 1998Mar 20 1998Extreme Scattering Events (ESEs) are attributed to radio-wave refraction by a cloud of free-electrons crossing the line-of-sight. We present a new model in which these electrons form the photo-ionized 'skin' of an underlying cool, self-gravitating cloud ... More
High velocity gas from the Galactic dark haloNov 13 1998We present the germ of a new model for High Velocity Clouds, derived from the idea that the dark matter halo of our Galaxy is in the form of cold, planetary-mass gas clouds. In this picture HVCs arise as a result of disruptive collisions between dark ... More
Order-Revealing Encryption and the Hardness of Private LearningMay 03 2015An order-revealing encryption scheme gives a public procedure by which two ciphertexts can be compared to reveal the ordering of their underlying plaintexts. We show how to use order-revealing encryption to separate computationally efficient PAC learning ... More
The Cloudy UniverseJul 20 1999Modelling of Extreme Scattering Events suggests that the Galaxy's dark matter is an undetected population of cold, AU-sized, planetary-mass gas clouds. None of the direct observational constraints on this picture -- thermal/non-thermal emission, extinction ... More
Thermal stability of cold clouds in galaxy halosJul 02 1999Oct 14 1999We consider the thermal properties of cold, dense clouds of molecular hydrogen and atomic helium. For cloud masses below 10^-1.7 Msun, the internal pressure is sufficient to permit the existence of particles of solid or liquid hydrogen at temperatures ... More
Non-equilibrium dynamics of bosonic atoms in optical lattices: Decoherence of many-body states due to spontaneous emissionSep 01 2010We analyze in detail the heating of bosonic atoms in an optical lattice due to incoherent scattering of light from the lasers forming the lattice. Because atoms scattered into higher bands do not thermalize on the timescale of typical experiments, this ... More
Andreev-like reflections with cold atomsOct 15 2007We propose a setup in which Andreev-like reflections predicted for 1D transport systems could be observed time-dependently using cold atoms in a 1D optical lattice. Using time-dependent Density Matrix Renormalisation Group methods we analyse the wavepacket ... More
Atom-only descriptions of the driven dissipative Dicke modelJan 08 2019We investigate how to describe the dissipative spin dynamics of the driven dissipative Dicke model, describing $N$ two-level atoms coupled to a cavity mode, after adiabatic elimination of the cavity mode. To this end, we derive a Redfield master equation ... More
Atomic matter-wave revivals with definite atom number in an optical latticeJan 12 2011We study the collapse and revival of interference patterns in the momentum distribution of atoms in optical lattices, using a projection technique to properly account for the fixed total number of atoms in the system. We consider the common experimental ... More
Time-dependent currents of 1D bosons in an optical latticeAug 18 2009Mar 03 2010We analyse the time-dependence of currents in a 1D Bose gas in an optical lattice. For a 1D system, the stability of currents induced by accelerating the lattice exhibits a broad crossover as a function of the magnitude of the acceleration, and the strength ... More
Dynamical disentangling and cooling of atoms in bilayer optical latticesSep 12 2016We show how experimentally available bilayer lattice systems can be used to prepare quantum many-body states with exceptionally low entropy in one layer, by dynamically disentangling the two layers. This disentangling operation moves one layer - subsystem ... More
Exotic atom pairs: Repulsively bound states in an optical latticeOct 14 2006We review a recent experiment with ultracold atoms in 3D optical lattices where we have observed a novel kind of bound state of two atoms which is based on repulsive interactions between the particles. These repulsively bound pairs exhibit long lifetimes, ... More
State-dependent lattices for quantum computing with alkaline-earth-metal atomsFeb 07 2011Recent experimental progress with Alkaline-Earth atoms has opened the door to quantum computing schemes in which qubits are encoded in long-lived nuclear spin states, and the metastable electronic states of these species are used for manipulation and ... More
Atom-only descriptions of the driven-dissipative Dicke modelJan 08 2019Mar 27 2019We investigate how to describe the dissipative spin dynamics of the driven-dissipative Dicke model, describing $N$ two-level atoms coupled to a cavity mode, after adiabatic elimination of the cavity mode. To this end, we derive a Redfield master equation ... More
The Question of Spontaneous Symmetry Breaking in CondensatesJul 27 2015The question of whether Bose-Einstein condensation involves spontaneous symmetry breaking is surprisingly controversial. We review the theory of spontaneous symmetry breaking in ferromagnets, compare it to the theory of symmetry breaking in condensates, ... More
Inhibition of the electron cyclotron maser instability in the dense magnetosphere of a hot JupiterJun 21 2018Hot Jupiter (HJ) type exoplanets are expected to produce strong radio emission in the MHz range via the Electron Cyclotron Maser Instability (ECMI). To date, no repeatable detections have been made. To explain the absence of observational results, we ... More
Hot Jupiter accretion: 3D MHD simulations of star-planet wind interactionDec 03 2018We present 3D MHD simulations of the wind-wind interactions between a solar type star and a short period hot Jupiter exoplanet. This is the first such simulation in which the stellar surface evolution is studied in detail. In our simulations, a planetary ... More
Analytical tools for single-molecule fluorescence imaging in celluloApr 14 2015Recent technological advances in cutting-edge ultrasensitive fluorescence microscopy have allowed single-molecule imaging experiments in living cells across all three domains of life to become commonplace. Single-molecule live-cell data is typically obtained ... More
Universal localisations and tilting modules for finite dimensional algebrasJul 24 2013We study universal localisations, in the sense of Cohn and Schofield, for finite dimensional algebras and classify them by certain subcategories of our initial module category. A complete classification is presented in the hereditary case as well as for ... More
Fluctuations in Statistical ModelsSep 10 2007The multiplicity fluctuations of hadrons are studied within the statistical hadron-resonance gas model in the large volume limit. The role of quantum statistics and resonance decay effects are discussed. The microscopic correlator method is used to enforce ... More
Can STAR $p+p$ data help constrain fragmentation functions for strange hadronsJun 09 2006STAR has measured a variety of strange particle species in $p+p$ collisions at $\sqrt{s}$=200 GeV. These high statistics data are ideal for comparing to existing leading- and next-to-leading order perturbative QCD (pQCD) models. Leading-order (LO) models ... More
On the Convergence of Soft Potential Dynamics to Hard Sphere DynamicsJan 16 2016We address a question raised in the work of Gallagher, Saint-Raymond and Texier (From Newton to Boltzmann: Hard Spheres and Short-range Potentials, Z\"urich Lectures in Advanced Mathematics, EMS, 2013) that concerns the convergence of soft-potential dynamics ... More
Theoretical Aspects of Cosmic AccelerationApr 29 2016Efforts to understand and map the possible explanations for the late time acceleration of the universe have led to a broad range of suggestions, ranging from the cosmological constant and straightforward dark energy, to exotically coupled models, to infrared ... More
A traditional tree-style tableau for LTLApr 13 2016Propositional linear time temporal logic (LTL) is the standard temporal logic for computing applications and many reasoning techniques and tools have been developed for it. Tableaux for deciding satisfiability have existed since the 1980s. However, the ... More
Connected-Sum Decompositions of Surfaces with Minimally-Intersecting Filling PairsMar 10 2016Let $ S_g $ be a closed surface of genus $ g $ and let $ (\alpha, \beta) $ be a filling pair on $ S_g $; then $ i(\alpha, \beta) \geq 2g-1 $, where $ i $ is the (geometric) intersection number. Aougab and Huang demonstrated that (exponentially many) minimally-intersecting ... More
On the Construction of Tight Gabor Frames for $\mathbb{C}^N$Nov 02 2016The construction of finite tight Gabor frames plays an important role in many applications. These applications include significant ones in signal and image processing. We limit ourselves to frames for the finite dimensional Hilbert space $\mathbb{C}^N$. ... More
Distribution of the transfer matrix in disordered wiresFeb 01 2016A closed expression is derived for the probability distribution of the transfer matrix of a particle moving in a one-dimensional system with delta-correlated, weak disorder. The change in the distribution as a function of wire length is described by a ... More
Novel Concept of the Magmatic Heat ExtractionAug 04 2015Enhanced Geothermal Systems are the primary sources of interest nowadays. The paper presents a novel concept for the extraction of the magmatic heat directly from the magma chamber by utilizing the thermodynamic Retrograde Condensation curve.
Controlled Algebra for Simplicial Rings and Algebraic K-theoryJan 30 2014Jun 21 2014We develop a version of controlled algebra for simplicial rings. This generalizes the methods which lead to successful proofs of the algebraic K- theory isomorphism conjecture (Farrell-Jones Conjecture) for a large class of groups. This is the first step ... More
Representation of Uncertainty for Limit ProcessesDec 07 2001Many mathematical models utilize limit processes. Continuous functions and the calculus, differential equations and topology, all are based on limits and continuity. However, when we perform measurements and computations, we can achieve only approximate ... More
Dynamical evolution of stellar clustersJun 23 2011The evolution of star clusters is determined by several internal and external processes. Here we focus on two dominant internal effects, namely energy exchange between stars through close encounters (two-body relaxation) and mass-loss of the member stars ... More
Mass loss of stars in star clusters: an energy source for dynamical evolutionSep 10 2012Dense star clusters expand until their sizes are limited by the tidal field of their host galaxy. During this expansion phase the member stars evolve and lose mass. We show that for clusters with short initial relaxation time scales (<~100 Myr) the dynamical ... More
On ad hoc routing with guaranteed deliveryApr 05 2008We point out a simple poly-time log-space routing algorithm in ad hoc networks with guaranteed delivery using universal exploration sequences.
On the Complexity of Real FunctionsFeb 15 2005We develop a notion of computability and complexity of functions over the reals, which seems to be very natural when one tries to determine just how "difficult" a certain function is. This notion can be viewed as an extension of both BSS computability ... More
Continuum Emission by Cooling CloudsNov 17 2007Sep 11 2008The collapse of baryons into the center of a host dark matter halo is accompanied by radiation that may be detectable as compact (< 10 kpc) UV-continuum and Lyman Alpha (hereafter Lya) emission with Lya luminosities as high as ~1e42-1e43 erg/s in halos ... More
Differential and graphical approaches to multistability theory for chemical reaction networksSep 02 2007The use of mathematical models has helped to shed light on countless phenomena in chemistry and biology. Often, though, one finds that systems of interest in these fields are dauntingly complex. In this paper, we attempt to synthesize and expand upon ... More
Path Integral Quantisation of Finite Noncommutative GeometriesJul 05 2000Nov 12 2002We present a path integral formalism for quantising gravity in the form of the spectral action. Our basic principle is to sum over all Dirac operators. The approach is demonstrated on two simple finite noncommutative geometries: the two-point space, and ... More
The effect of linear terms in a quadratic HamiltonianJun 19 2009For a non-relativistic particle subject to a Hamiltonian that is quadratic in position and momentum, with coefficients that may vary with time, it is shown that the effect of the linear terms in the Hamiltonian is just a spatial translation of the wave ... More
Cosmological Perturbations from Cosmic StringsDec 20 1994Some aspects of the theory of cosmological perturbations from cosmic strings and other topological defects are outlined, with particular reference to a simple example: a spatially flat CDM-dominated universe. The conserved energy-momentum pseudo-tensor ... More
Radio Galaxy Clustering at z~0.3Apr 30 2000Radio galaxies are uniquely useful as probes of large-scale structure as their uniform identification with giant elliptical galaxies out to high redshift means that the evolution of their bias factor can be predicted. As the initial stage in a project ... More
EMC effect, short-range nuclear correlations, neutron starsSep 16 2011Oct 25 2011The recent x>1 (e,e') and correlation experiments at momentum transfer Q^2 \ge 2 GeV^2 confirm presence of short-range correlations (SRC) in nuclei mostly build of nucleons. Recently we evaluated in a model independent way the dominant photon contribution ... More
Color transparency: 33 years and still runningNov 10 2007Jan 08 2008I review history of the color transparency (CT) which started with discovery of the $J/\psi$ meson, discovery of high energy CT phenomena and the recent progress in the investigations of CT at intermediate energies.
Spacetimes with SemanticsNov 20 2014Relationships between objects constitute our notion of space. When these relationships change we interpret this as the passage of time. Observer interpretations are essential to the way we understand these relationships. Hence observer semantics are an ... More
A Finite Element framework for computation of protein normal modes and mechanical responseApr 04 2007A coarse-grained computational procedure based on the Finite Element Method is proposed to calculate the normal modes and mechanical response of proteins and their supramolecular assemblies. Motivated by the elastic network model, proteins are modeled ... More
Interpretations of Negative ProbabilitiesAug 06 2010In this paper, we give a frequency interpretation of negative probability, as well as of extended probability, demonstrating that to a great extent, these new types of probabilities, behave as conventional probabilities. Extended probability comprises ... More
Isometric embeddings of dual polar graphs in Grassmann graphs over finite fieldsOct 04 2015We consider the Grassmann graphs and dual polar graphs over the same finite field and show that, up to graph automorphism, for every dual polar graph there is the unique isometric embedding in the corresponding Grassmann graph.
Characterizations of strong semilinear embeddings in terms of general linear and projective linear groupsJul 16 2012Nov 08 2012Let $V$ and $V'$ be vector spaces over division rings. Suppose $\dim V$ is finite and not less than 3. Consider a mapping $l:V\to V$ with the following property: for every $u\in {\rm GL}(V)$ there is $u'\in {\rm GL}(V')$ such that $lu=u'l$. Our first ... More
Automorphisms of infinite Johnson graphNov 10 2010Dec 24 2010We consider the {\it infinite Johnson graph} $J_{\infty}$ whose vertex set consists of all subsets $X\subset {\mathbb N}$ satisfying $|X|=|{\mathbb N}\setminus X|=\infty$ and whose edges are pairs of such subsets $X,Y$ satisfying $|X\setminus Y|=|Y\setminus ... More
Magnetically-Driven Winds from Protostellar DisksJul 21 1997Jul 22 1997Angular momentum transport in protostellar disks can be achieved by the action of a large scale magnetic field that runs vertically through the disk. The magnetic field centrifugally drives material from the disk surfaces into a wind, initiating a bipolar ... More
Dust grains and the structure of steady C-type magnetohydrodynamic shock waves in molecular cloudsFeb 20 1998May 08 1998I examine the role of dust grains in determining the structure of steady, cold, oblique C-type shocks in dense molecular gas. Gas pressure, the inertia of the charged components, and changes in ionisation are neglected. The grain charge and rate coefficients ... More
Clusters of Galaxies at z > 1Dec 18 1996Although field galaxy studies have begun to probe the universe at z > 1, evidence for galaxy clusters at such redshifts has been sparse. New observations are accumulating rapidly, however, providing new data on the early evolution of elliptical galaxies, ... More
Color-Selected High Redshift Galaxies and the HDFFeb 05 1998Apr 20 1998The quality, depth, and multi-color nature of the Hubble Deep Field images makes them an excellent resource for studying galaxies at z > 2 using selection techniques based on the presence of the 912A Lyman break. I present a descriptive review of this ... More
Cluster Ellipticals at High Redshift: The View from the Ground and with HSTJul 16 1995New ground-based and HST observations of distant clusters make it possible to trace the history of E/S0 galaxies to lookback times of ~10 $h_{50}^{-1}$ Gyr. The data strongly favor a scenario in which cluster ellipticals formed very early with a narrow ... More
Cobordism Invariance of the Homotopy Type of the Space of Positive Scalar Curvature MetricsSep 30 2011We show that the homotopy type of the space of metrics of positive scalar curvature on a smooth manifold remains unchanged, after application of surgery in codimension at least three to the underlying manifold. This result is originally due to V. Chernysh, ... More
Nonclassical Degrees of Freedom in the Riemann HamiltonianMay 12 2011Nov 14 2011The Hilbert-Polya conjecture states that the imaginary parts of the zeros of the Riemann zeta function are eigenvalues of a quantum hamiltonian. If so, conjectures by Katz and Sarnak put this hamiltonian in Altland and Zirnbauer's universality class C. ... More
The Onset of Chaos in the Quantum Hard-Sphere GasMay 20 1996We show that the condition for the appearance of quantum chaos (Wigner-Dyson distribution of energy eigenvalues, gaussian-random energy eigenfunctions) in a dilute gas of many hard spheres is $\lambda \ll \ell$, where $\lambda$ is the wavelength of a ... More
The Berry-Keating Hamiltonian and the Local Riemann HypothesisApr 11 2011May 31 2011The local Riemann hypothesis states that the zeros of the Mellin transform of a harmonic-oscillator eigenfunction (on a real or p-adic configuration space) have real part 1/2. For the real case, we show that the imaginary parts of these zeros are the ... More
The approach to thermal equilibrium in quantized chaotic systemsSep 25 1998Nov 16 1998We consider many-body quantum systems that exhibit quantum chaos, in the sense that the observables of interest act on energy eigenstates like banded random matrices. We study the time-dependent expectation values of these observables, assuming that the ... More
IIB or not IIBJul 19 1998Sep 03 1998We consider Type IIB superstring theory with the addition of n 9-branes and n anti-9-branes (and no orientifolds). The result is a ten-dimensional chiral theory of open and closed oriented strings with gauge group U(n) \times U(n). There is, however, ... More
Thermal Fluctuations in Quantized Chaotic SystemsNov 10 1995Dec 15 1995We consider a quantum system with $N$ degrees of freedom which is classically chaotic. When $N$ is large, and both $\hbar$ and the quantum energy uncertainty $\Delta E$ are small, quantum chaos theory can be used to demonstrate the following results: ... More
Hydrodynamic Detonation Instability in Electroweak and QCD Phase TransitionsMay 18 1993The hydrodynamic stability of deflagration and detonation bubbles for a first order electroweak and QCD phase transition has been discussed recently with the suggestion that detonations are stable. We examine here the case of a detonation more carefully. ... More
Boundary Forelli theorem for the sphere in $\mathbb C^n$ and $n+1$ bundles of complex linesMar 31 2010Let $B^n$ be the unit ball in $\mathbb C^n$ and let the points $a_1,...,a_{n+1} \in B^n $ are affinely independent. If $f \in C(\partial B^n)$ and for any complex line $L$, containing at least one of the points $a_j$, the restriction $f|_{L \cap \partial ... More
Open charm spectroscopy at LHCbSep 01 2015Recent charm spectroscopy results from Dalitz plot analyses of $B$ decays to open charm final states at LHCb are presented. The decay modes used are $B^{+} \to D^{-} K^{+} \pi^{+}$, $B^{0} \to \overline{D}{}^{0} \pi^{+} \pi^{-}$ and $B^{0} \to \overline{D}{}^{0} ... More
Large Rapidity Gap Events in DISJun 18 1997Diffractive scattering in DIS is discussed in terms of the perturbative two-gluon model and numerical results for $F_2^D$ are presented.
Primitive Calabi-Yau ThreefoldsDec 04 1995A primitive Calabi-Yau threefold is a non-singular Calabi-Yau threefold which cannot be written as a crepant resolution of a singular fibre of a degeneration of Calabi-Yau threefolds. These should be thought as the most basic Calabi-Yau manifolds; all ... More
An Introduction to the Quantum Theory of Nonlinear OpticsJan 22 2009This article is provides an introduction to the quantum theory of optics in nonlinear dielectric media. We begin with a short summary of the classical theory of nonlinear optics, that is nonlinear optics done with classical fields. We then discuss the ... More
Quantum cryptography with squeezed statesSep 01 1999A quantum key distribution scheme based on the use of displaced squeezed vacuum states is presented. The states are squeezed in one of two field quadrature components, and the value of the squeezed component is used to encode a character from an alphabet. ... More
The monodromies of homogeneous linksJun 30 2012We show that there are only finitely many homogeneous links whose Conway polynomial has any given degree. Using this we give an example of an inhomogeneous, fibred knot. Secondly, we show how to compute the monodromy of a homogeneous link complement from ... More
Invertibility of random matrices: norm of the inverseJul 01 2005Let A be an n by n matrix, whose entries are independent copies of a centered random variable satisfying the subgaussian tail estimate. We prove that the operator norm of A^{-1} does not exceed Cn^{3/2} with probability close to 1.
A Nondivergence Parabolic Problem with a Fractional Time derivativeJul 15 2015We study a nonlocal nonlinear parabolic problem with a fractional time derivative. We prove a Krylov-Safonov type result; mainly, we prove Holder regularity of solutions. Our estimates remain uniform as the order of the fractional time derivative approaches ... More
Caputo Standard $α$-Family of Maps: Fractional Difference vs. FractionalJun 16 2014In this paper the author compares behaviors of systems which can be described by fractional differential and fractional difference equations using the fractional and fractional difference Caputo Standard $\alpha$-Families of Maps as examples. The author ... More
The effect of alternative tree representations on tree bank grammarsNov 20 1997Nov 21 1997The performance of PCFGs estimated from tree banks is sensitive to the particular way in which linguistic constructions are represented as trees in the tree bank. This paper presents a theoretical analysis of the effect of different tree representations ... More