Results for "Michael R. Dellomo"

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Reactive Sensing and Multiplicative Frame Super-resolutionMar 13 2019The problem is to evaluate the behavior of an object when primary sources of information about the object become unavailable, so that any information must be obtained from the intelligent use of available secondary sources. This evaluative process is ... More
Providing Higher Throughput for a Single User with M-ary Orthogonal Walsh CodesOct 16 2014Reliable communication is a challenge in a very noisy RF channel further corrupted by severe, multiple narrowband interference. Code Division Multiple Access (CDMA) is a widely used method to both mitigate such interference and support multiple in-band ... More
Extremal Black Hole in a Nonlinear Newtonian Theory of GravityNov 12 2008This work investigates an upper-limit of charge for a black hole in a nonlinear Newtonian theory of gravity. The charge is accumulated via protons fired isotropically at the black hole. This theoretical study of gravity (known as `pseudo-Newtonian') is ... More
Reflections on a Black MirrorJan 31 2016Oct 30 2016A black mirror is an accelerated boundary that produces particles in an exact correspondence to an evaporating black hole. We investigate the spectral dynamics of the particle creation during the formation process.
On Spin-Statistics and Bogoliubov Transformations in Flat Spacetime With Acceleration ConditionsMay 04 2012Jan 31 2013A single real scalar field of spin zero obeying the Klein-Gordon equation in flat space-time under external conditions is considered in the context of the spin-statistics connection. An imposed accelerated boundary on the field is made to become, in the ... More
Evolving images of the proton: Hadron physics over the past 40 yearsApr 05 2016Once upon a time, the world was simple: the proton contained three quarks, two {\it ups} and a {\it down}. How these give the proton its mass and its spin seemed obvious. Over the past forty years the proton has become more complicated, and how even these ... More
Approximate Cech Complexes in Low and High DimensionsJul 11 2013\v{C}ech complexes reveal valuable topological information about point sets at a certain scale in arbitrary dimensions, but the sheer size of these complexes limits their practical impact. While recent work introduced approximation techniques for filtrations ... More
The Emergence of Classicality via Decoherence: Beyond the Caldeira-Legget EnvironmentDec 22 1994Maximally predictive states, as defined in recent work by Zurek, Habib and Paz, are studied for more elaborate environment models than a linear coupling. An environment model which includes spatial correlations in the noise is considered in the non-dissipative ... More
A simple model for the clustering of subhalos as a function of massApr 16 2003Astrophysicists do not associate galaxies with the massive dark matter halos so easily detected in particle simulations and whose mass function can be predicted by the Press-Schechter formalism and its variants. Instead, they associate galaxies with smaller ... More
Dynamics of Electrons in Graded SemiconductorsDec 04 1996I present a theory of electron dynamics in semiconductors with slowly varying composition. I show that the frequency-dependent conductivity, required for the description of transport and optical properties, can be obtained from a knowledge of the band ... More
Current-Carrying Ground States in Mesoscopic and Macroscopic SystemsJul 01 1995We extend a theorem of Bloch, which concerns the net orbital current carried by an interacting electron system in equilibrium, to include mesoscopic effects. We obtain a rigorous upper bound to the allowed ground-state current in a ring or disc, for an ... More
Effective potential and warp factor dynamicsNov 17 2009Dec 26 2009We define an effective potential describing all massless and massive modes in the supergravity limit of string/M theory compactification which is valid off-shell, i.e. without imposing the equations of motion. If we neglect the warp factor, it is unbounded ... More
Statistics of String vacuaJan 01 2004We give an introduction to the statistical approach to studying vacua of string/M theory, and discuss recent results of Ashok and Douglas on counting supersymmetric flux vacua in type IIb Calabi-Yau compactification. To appear in the proceedings of the ... More
D-branes and Discrete TorsionJul 30 1998We show that discrete torsion is implemented in a D-brane world-volume theory by using a projective representation of the orbifold point group. We study the example of C^3/Z_2 x Z_2 and show that the resolution of singularities agrees with that proposed ... More
Conformal Field Theory Techniques for Large N Group TheoryMar 30 1993We show how to use quantum mechanics on the group manifold U(N) as a tool for problems in U(N) representation theory. The quantum mechanics reduces to free fermions on the circle, which in the large N limit become relativistic. The theory can be bosonized ... More
Probing reionization with Lyman-alpha emission linesAug 11 2003Lyman-alpha emission from high-redshift galaxies may be a powerful probe of the ionization history of the IGM at z>6: the observed Lyman-alpha emission line is sensitive to the neutral fraction of IGM hydrogen in the range 0.1-1. We present calculations ... More
Dimension Reduction for the Landau-de Gennes Model: The Vanishing Nematic Correlation Length LimitJan 13 2018Sep 10 2018We study nematic liquid crystalline films within the framework of the Landau-de Gennes theory in the limit when both the thickness of the film and the nematic correlation length are vanishingly small compared to the lateral extent of the film. We prove ... More
Landau level quantization for massless Dirac fermions in the spherical geometry: graphene fractional quantum Hall effect on the Haldane sphereFeb 12 2016Jul 05 2016We derive the single-particle eigenenergies and eigenfunctions for massless Dirac fermions confined to the surface of a sphere in the presence of a magnetic monopole, i.e., we solve the Landau level problem for electrons in graphene on the Haldane sphere. ... More
Quantum Phenomena in Low-Dimensional SystemsJun 13 2001A brief summary of the physics of low-dimensional quantum systems is given. The material should be accessible to advanced physics undergraduate students. References to recent review articles and books are provided when possible.
Instanton method for the electron propagatorMay 08 2001A nonperturbative theory of the electron propagator is developed and used to calculate the one-particle Green's function and tunneling density-of-states in strongly correlated electron systems. The method, which is based on a Hubbard-Stratonovich decoupling ... More
New sum rules for an electron in a periodic or nearly periodic potentialApr 15 1996I derive new sum rules for the electronic oscillator strengths in a periodic or nearly periodic potential, which apply within a single energy band and between any two bands. The physical origin of these sum rules is quite unlike that of conventional sum ... More
Basic results in Vacuum StatisticsSep 20 2004A review of recent work on constructing and finding statistics of string theory vacua, done in collaboration with Frederik Denef, Bogdan Florea, Bernard Shiffman and Steve Zelditch.
The statistics of string/M theory vacuaMar 21 2003Apr 24 2003We discuss systematic approaches to the classification of string/M theory vacua, and physical questions this might help us resolve. To this end, we initiate the study of ensembles of effective Lagrangians, which can be used to precisely study the predictive ... More
D-branes and Matrix Theory in Curved SpaceJul 28 1997Aug 21 1997We discuss the relation between supersymmetric gauge theory of branes and supergravity; as it was discovered in D-brane physics, and as it appears in Matrix theory, with emphasis on motion in curved backgrounds. We argue that gauged sigma model Lagrangians ... More
Superstring Dualities, Dirichlet Branes and the Small Scale Structure of SpaceOct 07 1996We give a broad overview of superstring duality, Dirichlet branes, and some implications of both for questions about the structure of space-time at short distances.
Branes within BranesDec 12 1995Dec 21 1995We discuss a set of universal couplings between superstring Ramond-Ramond gauge fields and the gauge fields internal to D-branes, with emphasis on their topological consequences, and argue that instanton solutions in these internal theories are equivalent ... More
Large N Gauge Theory -- Expansions and TransitionsSep 18 1994Sep 24 1994We use solvable two-dimensional gauge theories to illustrate the issues in relating large N gauge theory to string theory. We also give an introduction to recent mathematical work which allows constructing master fields for higher dimensional large N ... More
Understanding the landscapeFeb 24 2006Based on comments made at the 23rd Solvay Conference, December 2005, Brussels.
D-Branes in Curved SpaceMar 06 1997Jul 22 1997We obtain actions for N D-branes occupying points in a manifold with arbitrary Kahler metric. In one complex dimension, the action is uniquely determined (up to second order in commutators) by the requirement that it reproduce the masses of stretched ... More
Gauge Fields and D-branesApr 30 1996We prove that self-dual gauge fields in type I superstring theory are equivalent to configurations of Dirichlet 5-branes, by showing that the world-sheet theory of a Dirichlet 1-brane moving in a background of 5-branes includes an ``ADHM sigma model.'' ... More
Chern-Simons-Witten Theory as a Topological Fermi LiquidMar 21 1994We reinterpret U(N) Chern-Simons-Witten theory quantized on a torus as a free fermion system. Its Hilbert space and some observables are simply related to those of group quantum mechanics, even at finite N and k. Its large N limit can be described using ... More
Effects of fluctuation on alpha-omega dynamo modelsAug 23 2007We analyse the role of a fluctuating alpha-effect in alpha-omega dynamo models, and show that there is a mechanism for magnetic field generation, valid at large scale separation, deriving from the interaction of mean shear and a fluctuating alpha-effect. ... More
Galaxies: From Kinematics to DynamicsNov 30 2000These lectures are intended to provide an introduction to the rich interplay between N-body simulations and stellar-kinematic observations of galaxies. The first section describes the kinematic properties of galaxies that are accessible to observation, ... More
D-Branes on Calabi-Yau ManifoldsSep 22 2000We give an overview of recent work on Dirichlet branes on Calabi-Yau threefolds which makes contact with Kontsevich's homological mirror symmetry proposal, proposes a new definition of stability which is appropriate in string theory, and provides concrete ... More
Dirichlet branes, homological mirror symmetry, and stabilityJul 02 2002Jul 05 2002We discuss some mathematical conjectures which have come out of the Dirichlet branes in superstring theory, focusing on the case of supersymmetric branes in Calabi-Yau compactification. This has led to the formulation of a notion of stability for objects ... More
An Integral Kernel for Weakly Pseudoconvex DomainsFeb 01 2012A new explicit construction of Cauchy-Fantappi\'e kernels is introduced for an arbitrary weakly pseudoconvex domain with smooth boundary. While not holomorphic in the parameter, the new kernel reflects the complex geometry and the Levi form of the boundary. ... More
A Hybrid Latent Variable Neural Network Model for Item RecommendationJun 09 2014Collaborative filtering is used to recommend items to a user without requiring a knowledge of the item itself and tends to outperform other techniques. However, collaborative filtering suffers from the cold-start problem, which occurs when an item has ... More
On the Role of Minor Galaxy Mergers in the Formation of Active Galactic NucleiApr 18 2000The large scale (~ 100 kpc) environments of Seyfert galaxies are not significantly different from those of non-Seyfert galaxies. In the context of the interaction model of the formation of active galactic nuclei (AGN), it has been proposed that AGN form ... More
The Age of the Galactic BulgeAug 07 2001The dominant stellar population of the central bulge of the Milky Way is old, with roughly solar metallicity. The age is very similar to that of the old metal rich bulge globular clusters and to 47 Tucanae, which has an age of 13 Gyr. Stellar composition ... More
The Stellar Phase Density of the Local Universe and its Implications for Galaxy EvolutionAug 25 2010This paper introduces the idea that the general mixing inequality obeyed by evolving stellar phase densities may place useful constraints on the possible history of the over-all galaxy population. We construct simple models for the full stellar phase ... More
Buckling Bars and Boxy BulgesAug 08 1995It has been suggested that the peanut-shaped bulges seen in some edge-on disk galaxies are produced when bars in these galaxies buckle. This paper reviews the modelling which seeks to show how bars buckle, and I present a very simple new model which captures ... More
The Emergence of Classicality via Decoherence Described by Lindblad OperatorsJun 13 1995Jun 13 1995Zurek, Habib and Paz [W. H. Zurek, S. Habib and J. P. Paz, Phys. Rev. Lett. {\bf 70} (1993)\ 1187] have characterized the set of states of maximal stability defined as the set of states having minimum entropy increase due to interaction with an environment, ... More
Decoherence and Dissipation for a Quantum System Coupled to a Local EnvironmentOct 19 1993Decoherence and dissipation in quantum systems has been studied extensively in the context of Quantum Brownian Motion. Effective decoherence in coarse grained quantum systems has been a central issue in recent efforts by Zurek and by Hartle and Gell-Mann ... More
Measurement of D-meson azimuthal anisotropy in Au+Au 200 GeV collisions at RHICJan 05 2016Heavy quarks are produced through initial hard scatterings and they are affected by the hot and dense medium created in heavy-ion collisions throughout its whole evolution. Due to their heavy mass, charm quarks are expected to thermalize much more slowly ... More
A Gaussian correlation inequality for convex setsSep 06 2013Dec 31 2015A Gaussian correlation inequality is proven which generalises results of Schechtman, Schlumprecht \& Zinn , Li and Shao. One implication of this inequality is that, for the standard Gaussian measure $\gamma$ on $R^n$, the inequality $$ |\sin(\alpha + ... More
Controlling arbitrary nxn unitaries with a complete graph of n+1 qubits: Beyond the single-excitation subspaceOct 06 2015Quantum computation and simulation with a complete graph of superconducting qubits has been proposed [PRA 91, 062309 (2015)]. The method does not require error correction and is practical now. By controlling the vertices (qubits) and edges (couplers) ... More
On D=5 super Yang-Mills theory and (2,0) theoryDec 13 2010Jan 04 2011We discuss how D=5 maximally supersymmetric Yang-Mills theory (MSYM) might be used to study or even to define the (2,0) theory in six dimensions. It is known that the compactification of (2,0) theory on a circle leads to D=5 MSYM. A variety of arguments ... More
Random algebraic geometry, attractors and flux vacuaAug 09 2005This is a submission to the Encyclopedia of Mathematical Physics (Elsevier, 2006) and conforms to its referencing guidelines.
Compactification of superstring theoryAug 05 2005Aug 09 2005This article will appear in the Encyclopedia of Mathematical Physics (Elsevier, 2006) and follows its referencing guidelines.
Topics in D-geometryOct 21 1999Nov 15 1999We discuss the general theory of D-branes on Calabi-Yaus, recent results from the theory of boundary states, and new results on the spectrum of branes on the quintic CY. (Contribution to the proceedings of Strings '99 in Potsdam, Germany.)
Stochastic Master FieldsNov 03 1994Nov 15 1994We treat the stochastic equation for large N master fields proposed by Greensite and Halpern using a construction of master fields modelled after work of Voiculescu, and show that it contains the same information as the usual factorized Schwinger-Dyson ... More
The string landscape and low energy supersymmetryApr 30 2012May 03 2012We briefly survey our present understanding of the string landscape, and use it to discuss the chances that we will see low energy supersymmetry at the LHC.
Spaces of Quantum Field TheoriesMay 16 2010May 18 2010The concept of a "space of quantum field theories" or "theory space" was set out in the 1970's in work of Wilson, Friedan and others. This structure should play an important role in organizing and classifying QFTs, and in the study of the string landscape, ... More
Enhanced Gauge Symmetry in M(atrix) TheoryDec 11 1996We discuss the origin of enhanced gauge symmetry in ALE (and K3) compactification of M theory, either defined as the strong coupling limit of the type IIa superstring, or as defined by Banks et al. In the D-brane formalism, wrapped membranes are D0 branes ... More
Convergence of Polynomial Ergodic Averages of Several Variables for some Commuting TransformationsJun 17 2009Let $(X,\mathcal{B},\mu)$ be a probability space and let $T_1,..., T_l$ be $l$ commuting invertible measure preserving transformations \linebreak of $X$. We show that if $T_1^{c_1} ... T_l^{c_l}$ is ergodic for each $(c_1,...,c_l)\neq (0,...,0)$, then ... More
Numerical Solution of the Beltrami EquationFeb 08 2008Mar 08 2018An effective algorithm is presented for solving the Beltrami equation fzbar = mu fz in a planar disk. The algorithm involves no evaluation of singular integrals. The strategy, working in concentric rings, is to construct a piecewise linear mu-conformal ... More
Arbitrage theory without a numéraireOct 11 2014Jul 04 2015This note develops an arbitrage theory for a discrete-time market model without the assumption of the existence of a num\'eraire asset. Fundamental theorems of asset pricing are stated and proven in this context. The distinction between the notions of ... More
Education and Outreach in Particle PhysicsSep 30 2011There are many varied programs of education and outreach in particle physics. This report for the Division of Particles and Fields of the American Physical Society 2001 meeting reviews the impact of these programs in general, and also gives several examples ... More
Inequalities for the Gaussian measure of convex setsSep 06 2013Jul 12 2017This note presents families of inequalities for the Gaussian measure of convex sets which extend the recently proven Gaussian correlation inequality in various directions.
The Bulge Radial Velocity/Abundance AssayAug 30 2011The Bulge Radial Velocity/Abundance Assay (BRAVA) has accomplished a survey of 10,000 red giants in the Southern Galactic bulge, approximately spanning -8 deg. < l < +8 deg. and -3 deg. <b < -8 deg., a region within roughly 1 kpc from the nucleus. We ... More
Local Universe Science with the E-ELTAug 16 2010This paper briefly reviews some of the exciting studies of the local Universe that will be enabled with the European Extremely Large Telescope (E-ELT). As illustrative examples, it summarizes a few of the scientific goals that have been set for this instrument ... More
Toward a Universal Cortical Algorithm: Examining Hierarchical Temporal Memory in Light of Frontal Cortical FunctionNov 18 2014A wide range of evidence points toward the existence of a common algorithm underlying the processing of information throughout the cerebral cortex. Several hypothesized features of this cortical algorithm are reviewed, including sparse distributed representation, ... More
Galaxies in SDSS and DEEP2: a quiet life on the blue sequence?Dec 05 2005In the six billion years between redshifts z=1 and z=0.1, galaxies change due to the aging of their stellar populations, the formation of new stars, and mergers with other galaxies. Here I explore the relative importance of these various effects, finding ... More
Local Phonon Density of States in an Elastic SubstrateJun 03 2004The local, eigenfunction-weighted acoustic phonon density of states (DOS) tensor is calculated for a model substrate consisting of a semi-infinite isotropic elastic continuum with a stress-free surface. On the surface, the local DOS is proportional to ... More
Calabi-Yau metrics and string compactificationMar 10 2015Apr 13 2015Yau proved an existence theorem for Ricci-flat K\"ahler metrics in the 1970's, but we still have no closed form expressions for them. Nevertheless there are several ways to get approximate expressions, both numerical and analytical. We survey some of ... More
Statistical analysis of the supersymmetry breaking scaleMay 30 2004Jun 29 2004We discuss the question of what type and scale of supersymmetry breaking might be statistically favored among vacua of string/M theory, building on comments in Denef and Douglas, hep-th/0404116.
D-Branes and N=1 SupersymmetryMay 02 2001We discuss the recent proposal that BPS D-branes in Calabi-Yau compactification of type II string theory are Pi-stable objects in the derived category of coherent sheaves.
D-branes, Categories and N=1 SupersymmetryNov 02 2000Apr 13 2001We show that boundary conditions in topological open string theory on Calabi-Yau manifolds are objects in the derived category of coherent sheaves, as foreseen in the homological mirror symmetry proposal of Kontsevich. Together with conformal field theory ... More
Two Lectures on D-Geometry and Noncommutative GeometryJan 27 1999Feb 01 1999This is a write-up of lectures given at the 1998 Spring School at the Abdus Salam ICTP. We give a conceptual introduction to D-geometry, the study of geometry as seen by D-branes in string theory, and to noncommutative geometry as it has appeared in D-brane ... More
Some Comments on QCD StringJan 14 1994We try to draw lessons for higher dimensions from the string representations recently derived for large $N$ Yang-Mills theory by Gross and Taylor, Kostov, and others, and call attention to three characteristics that should be expected of a string theory ... More
Keynote Paper: Cell-Surface Adhesive Interactions in Microchannels and MicrovesselsJul 01 2003Adhesive interactions between white blood cells and the interior surface of the blood vessels they contact is important in inflammation and in the progression of heart disease. Parallel-plate microchannels have been useful in characterizing the strength ... More
If $B$ and $f(B)$ are Brownian motions, then $f$ is affineJul 11 2013Aug 19 2015It is shown that if the processes $B$ and $f(B)$ are both Brownian motions (without a random time change) then $f$ must be an affine function. As a by-product of the proof, it is shown that the only functions which are solutions to both the Laplace equation ... More
Calls, zonoids, peacocks and log-concavityOct 28 2016The main results are two characterisations of log-concave densities in terms of the collection of lift zonoids corresponding to a peacock. These notions are recalled and connected to arbitrage-free asset pricing in financial mathematics.
Two Groups of Nearly Coeval Star Clusters in the Small Magellanic CloudJul 28 1999We report new photometry of populous intermediate-age clusters in the SMC using the {\sl Hubble Space Telescope}. In contrast to the accepted picture, these clusters appear to have formed in two brief intervals, one $8\pm 2$ Gyr ago, and a more recent ... More
Phase-Coherent Transport through a Mesoscopic System: A New Probe of Non-Fermi-Liquid BehaviorApr 22 1998A novel chiral interferometer is proposed that allows for a direct measurement of the phase of the transmission coefficient for transport through a variety of mesoscopic structures in a strong magnetic field. The effects of electron-electron interaction ... More
Numerical Solution of the Beltrami EquationFeb 08 2008Mar 03 2015An effective algorithm is presented for solving the Beltrami equation fzbar = mu fz in a planar disk. The algorithm involves no evaluation of singular integrals. The strategy, working in concentric rings, is to construct a piecewise linear mu-conformal ... More
Conformal Field Theory Techniques in Large N Yang-Mills TheoryNov 22 1993Following some motivating comments on large N two-dimensional Yang-Mills theory, we discuss techniques for large N group representation theory, using quantum mechanics on the group manifold U(N), its equivalence to a quasirelativistic two-dimensional ... More
Open environments for quantum open systemsOct 08 2002The majority of quantum open system models in the literature are simplistic in the sense that they only explicitly account for that part of the environment that directly interacts with the system of interest. A quantum open system with an open environment ... More
Outreach and Education on High Energy PhysicsOct 25 1994We review ongoing efforts and discuss possible future directions in informing the public and educating students about Particle Physics.
Re-Examination of Globally Flat Space-TimeNov 10 2013Jan 03 2014In the following, we offer a novel approach to modeling the observed effects currently attributed to the theoretical concepts of `dark energy', `dark matter', and `dark flow'. Instead of assuming the existence of these theoretical concepts, we take an ... More
On Sturm-Liouville Equations with Several Spectral ParametersApr 08 2015We give explicit formulas for a pair of linearly independent solutions of $(py')'(x)+q(x)=(\lambda_1r_1(x)+\cdots+\lambda_dr_d(x))y(x)$, thus generalizing to arbitrary $d$ previously known formulas for $d=1$. These are power series in the spectral parameters ... More
Uniform bounds for Black--Scholes implied volatilityDec 21 2015Aug 31 2016In this note, Black--Scholes implied volatility is expressed in terms of various optimisation problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. Various symmetries of the Black--Scholes ... More
Bootstrapping the Grenander estimatorMay 16 2008The goal of this paper is to study the bootstrap for the Grenander estimator. The first result is a proof of the inconsistency of the nonparametric bootstrap for the Grenander estimator at a given point. The second result is the development and verification ... More
A Black--Scholes inequality: applications and generalisationJan 14 2017Jan 27 2017The space of call price functions has a natural noncommutative semigroup structure with an involution. A basic example is the Black--Scholes call price surface, from which an interesting inequality for Black--Scholes implied volatility is derived. The ... More
Composition of the Galactic bulgeDec 27 2003We present detailed abundance results for 9 Galactic bulge stars in Baade's Window, based on HIRES (R=45,000--60,000) spectra taken with the Keck I telescope. The alpha elements show non-uniform enhancements relative to the Solar neighborhood trends: ... More
Bending a Beam to Significantly Reduce Wakefields of Short BunchesAug 23 2011A method of significantly reducing wakefields generated at collimators is proposed, in which the path of a beam is slightly bent before collimation. This is applicable for short bunches and can reduce the wakefields by a factor of around 7 for present ... More
The Influence of Non-Uniform Cloud Cover on Transit Transmission SpectraNov 30 2015Feb 16 2016We model the impact of non-uniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly ... More
Calculating the Fundamental Group of the Circle in Homotopy Type TheoryJan 15 2013Recent work on homotopy type theory exploits an exciting new correspondence between Martin-Lof's dependent type theory and the mathematical disciplines of category theory and homotopy theory. The category theory and homotopy theory suggest new principles ... More
Correlation Classes on the Landscape: To What Extent is String Theory Predictive?Aug 30 2008In light of recent discussions of the string landscape, it is essential to understand the degree to which string theory is predictive. We argue that it is unlikely that the landscape as a whole will exhibit unique correlations amongst low-energy observables, ... More
Fighting the Floating Correlations: Expectations and Complications in Extracting Statistical Correlations from the String Theory LandscapeOct 31 2006The realization that string theory gives rise to a huge landscape of vacuum solutions has recently prompted a statistical approach towards extracting phenomenological predictions from string theory. Unfortunately, for most classes of string models, direct ... More
How to Extrapolate A String Model to Finite Temperature: Interpolations and Implications for the Hagedorn TransitionJul 20 2005In this paper, we discuss the important question of how to extrapolate a given zero-temperature string model to finite temperature. It turns out that this issue is surprisingly subtle, and we show that many of the standard results require modification. ... More
Equilibrium Current and Orbital Magnetization in a Quantum Hall FluidFeb 19 1995We present a general theory for the equilibrium current distribution in an interacting two-dimensional electron gas subjected to a perpendicular magnetic field, and confined by a potential that varies slowly on the scale of the magnetic length. The distribution ... More
Quantum Breathing Mode for Electrons with 1/r^2 InteractionJun 19 1995We discuss a collective "breathing" mode of electrons with inverse-square-law interactions in a two-dimensional quantum dot and a perpendicular magnetic field.
Cosmic Microwave Background and Supernova Constraints on Quintessence: Concordance Regions and Target ModelsMay 19 2003We perform a detailed comparison of the Wilkinson Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy with the predictions of quintessence cosmological models of dark energy. ... More
Flux CompactificationOct 09 2006Jan 12 2007We review recent work in which compactifications of string and M theory are constructed in which all scalar fields (moduli) are massive, and supersymmetry is broken with a small positive cosmological constant, features needed to reproduce real world physics. ... More
Distributions of nonsupersymmetric flux vacuaNov 19 2004Mar 15 2005We continue the study of the distribution of nonsupersymmetric flux vacua in IIb string theory compactified on Calabi-Yau manifolds, as in hep-th/0404116. We show that the basic structure of this problem is that of finding eigenvectors of the matrix of ... More
Five-branes in M(atrix) TheoryOct 30 1996We propose a construction of five-branes which fill both light-cone dimensions in Banks, Fischler, Shenker and Susskind's matrix model of M theory. We argue that they have the correct long-range fields and spectrum of excitations. We prove Dirac charge ... More
More Realistic Hamiltonians for the Fractional Quantum Hall Regime in GaAs and GrapheneMar 06 2013Jul 02 2013We construct an effective Hamiltonian for electrons in the fractional quantum Hall regime for GaAs and graphene that takes into account Landau level mixing (for both GaAs and graphene) and subband mixing (for GaAs, due to the nonzero width of the quantum ... More
The First Detailed Abundances for M giants in Baade's Window from Infrared SpectroscopyJun 02 2005We report the first abundance analysis of 14 M giant stars in the Galactic bulge, based on R=25,000 infrared spectroscopy (1.5-1.8um) using NIRSPEC at the Keck II telescope. Because some of the bulge M giants reach high luminosities and have very late ... More
On the $L^p$ boundedness of wave operators for four-dimensional Schrödinger Operators with a threshold eigenvalueJun 21 2016Oct 10 2016Let $H=-\Delta+V$ be a Schr\"odinger operator on $L^2(\mathbb R^4)$ with real-valued potential $V$, and let $H_0=-\Delta$. If $V$ has sufficient pointwise decay, the wave operators $W_{\pm}=s-\lim_{t\to \pm\infty} e^{itH}e^{-itH_0}$ are known to be bounded ... More