Searching Arxiv, refresh for possibly better results.

Results for "B. Westhenry"

total 76316took 0.14s
Observation of weakened V-V dimers in the monoclinic metallic phase of strained VO2Mar 13 2019Emergent order at mesoscopic length scales in condensed matter can provide fundamental insight into the underlying competing interactions and their relationship with the order parameter. Using spectromicroscopy, we show that mesoscopic stripe order near ... More
Certain Topics on the Lie Algebra gl(lambda) Representation TheoryMar 15 1997The Lie algebra gl(lambda) dependent on the complex parameter lambda is a continuous version of the Lie algebra gl(inf) of infinite matrices with only finite number of nonzero entries. The gl(lambda) was first introduced by B.L.Feigin in [1] in connection ... More
Consequences of energy conservation in relativistic heavy-ion collisionsAug 15 2005Complete characterization of particle production and emission in relativistic heavy-ion collisions is in general not feasible experimentally. This work demonstrates, however, that the availability of essentially complete pseudorapidity distributions for ... More
Studies of multiplicity in relativistic heavy-ion collisionsNov 08 2004Nov 29 2004In this talk I'll review the present status of charged particle multiplicity measurements from heavy-ion collisions. The characteristic features of multiplicity distributions obtained in Au+Au collisions will be discussed in terms of collision centrality ... More
Pseudorapidity Distribution of Charged Particles in d + Au Collisions at $\sqrt{s_{_{NN}}$ = 200 GeVNov 10 2003The measured pseudorapidity distribution of primary charged particles in minimum-bias d + Au collisions at ${\sqrt{s_{_{NN}}} = \rm {200 GeV}}$ is presented for the first time. This distribution falls off less rapidly in the gold direction as compared ... More
The Radioactive Beam Program at ArgonneJun 06 2006In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer. ... More
Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeVApr 18 2001We have measured the ratios of antiparticles to particles for charged pions, kaons and protons near mid-rapidity in central Au+Au collisions at sqrt(s_NN) = 130 GeV. For protons, we observe pbar/p = 0.60 +/- 0.04 (stat.) +/- 0.06 (syst.) in the transverse ... More
Towards a strong-coupling theory of QCD at finite densitySep 02 2002We apply strong-coupling perturbation theory to the QCD lattice Hamiltonian. We begin with naive, nearest-neighbor fermions and subsequently break the doubling symmetry with next-nearest-neighbor terms. The effective Hamiltonian is that of an antiferromagnet ... More
Blandford's Argument: The Strongest Continuous Gravitational Wave SignalApr 18 2008Aug 18 2008For a uniform population of neutron stars whose spin-down is dominated by the emission of gravitational radiation, an old argument of Blandford states that the expected gravitational-wave amplitude of the nearest source is independent of the deformation ... More
Time Evolution of the Spread of Diseases with a General Infectivity Profile on a Complex Dynamic NetworkMay 21 2010This manuscript introduces a new analytical approach for studying the time evolution of disease spread on a finite size network. Our methodology can accommodate any disease with a general infectivity profile. This new approach is able to incorporate the ... More
Geometrically thin accretion disk around Maclaurin spheroidNov 22 2014We investigated a semi-analytic and numerical model to study the geometrically thin and optically thick accretion disk around Maclaurin spheroid (MS). The main interest is in the inner region of the so called {\alpha}-disk, {\alpha} being the viscosity ... More
A Search for Gamma-Ray Bursts and Pulsars, and the Application of Kalman Filters to Gamma-Ray ReconstructionFeb 04 2002Part I describes the analysis of periodic and transient signals in EGRET data. A method to search for the transient flux from gamma-ray bursts independent of triggers from other gamma-ray instruments is developed. Several known gamma-ray bursts were independently ... More
Heat Transfer and Cooling Techniques at Low TemperatureJan 28 2015The first part of this chapter gives an introduction to heat transfer and cooling techniques at low temperature. We review the fundamental laws of heat transfer (conduction, convection and radiation) and give useful data specific to cryogenic conditions ... More
A note on the heat kernel coefficients for nonminimal operatorsAug 20 2008We consider certain results for the heat kernel of nonminimal operators. The general expressions provided by Gusynin and Kornyak resulting from symbolic computation programmes for n dimensions are evaluated for 4 dimensions which are checked against results ... More
Lectures on UnificationNov 30 1997In these lectures we review the motivation, principles of and (circumstantial) evidence for the program of unification of the fundamental forces. In an appendix, we review the group theory pertinent to the program.
The Nobel Prize in Physics 2002 for the observation of cosmic neutrinosNov 06 2002A brief description of the work for which the first half of the Nobel prize for physics for the year 2002 is presented.
Infra-red fixed points in supersymmetryMar 16 2000Model independent constraints on supersymmetric models emerge when certain couplings are drawn towards their infra-red (quasi) fixed points in the course of their renormalization group evolution. The general principles are first reviewed and the conclusions ... More
Path Integral Monte Carlo and Density Functional Molecular Dynamics Simulations of Hot, Dense HeliumMay 02 2008Two first-principles simulation techniques, path integral Monte Carlo (PIMC) and density functional molecular dynamics (DFT-MD), are applied to study hot, dense helium in the density-temperature range of 0.387 - 5.35 g/cc and 500 K - 1.28x10^8 K. One ... More
First Principles Calculations of Shock Compressed Fluid HeliumSep 25 2006The properties of hot dense helium at megabar pressures were studied with two first-principles computer simulation techniques, path integral Monte Carlo and density functional molecular dynamics. The simulations predicted that the compressibility of helium ... More
Perturbative Energy Shifts of the Luttinger Liquid Due to the Presence of Additional DimensionsSep 26 2003We consider a system of spinless fermions in a nearly one-dimensional cylindrical trap. We introduce four-fermion interaction terms through which particles in low-lying modes of the trap may interact with particles in radially or angularly excited states. ... More
To the measurement of the radius via an electron scatteringOct 04 2015We propose an experiment for an accurate measurement of the proton radius. A key feature of our proposal is an iron-free magnetic spectrometer. Projected systematics uncertainties will allow a 1% level accuracy for the $r_p$ value.
Searching for a U-boson with a positron beamJun 29 2009A high sensitivity search for a light \Ub{} by means of a positron beam incident on a hydrogen target is proposed. We described a concept of the experiment and two possible realizations. The projected result of this experiment corresponds to an upper ... More
On measurement of the isotropy of the speed of lightSep 22 2014Nov 28 2014Three experimental concepts investigating possible anisotropy of the speed of light are presented. They are based on i) beam deflection in a 180 degree magnetic arc, ii) narrow resonance production in an electron-positron collider, and iii) the ratio ... More
Imperfect World of $ββ$-decay Nuclear Data Sets?Jan 09 2015Mar 11 2015The precision of double-beta ($\beta\beta$) decay experimental half-lives and their uncertainties is reevaluated. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection ... More
The measurements of the anomalous like-sign dimuon charge asymmetry in $p \bar{p}$ collisions by the DØ CollaborationFeb 18 2013In this short review we present the history, an overview of the analysis, and some personal comments on the anomalous like-sign dimuon charge asymmetry measurements by the D\O\ Collaboration.
Study of baryon acoustic oscillations with SDSS DR12 data and measurements of $Ω_k$ and $Ω_\textrm{DE}(a)$. Part IIAug 30 2016We define Baryon Acoustic Oscillation (BAO) observables $\hat{d}_\alpha(z, z_c)$, $\hat{d}_z(z, z_c)$, and $\hat{d}_/(z, z_c)$ that do not depend on any cosmological parameter. From each of these observables we recover the BAO correlation length $d_\textrm{BAO}$ ... More
Study of baryon acoustic oscillations with SDSS DR12 data and measurement of $Ω_\textrm{DE}(a)$Jul 08 2016We define Baryon Acoustic Oscillation (BAO) distances $\hat{d}_\alpha(z, z_c)$, $\hat{d}_z(z, z_c)$, and $\hat{d}_/(z, z_c)$ that do not depend on cosmological parameters. These BAO distances are measured as a function of redshift $z$ with the Sloan Digital ... More
Trying to understand massSep 12 2006We try to understand how particles acquire mass in general, and in particular, how they acquire mass in the standard model and beyond.
Simple model of 1/f noiseJun 16 1998Simple analytically solvable model of 1/f noise is proposed. The model consists of one or few particles moving in the closed contour. The drift period of the particle round the contour fluctuates about some average value, e.g. due to the external random ... More
Recent results on D^0 mixing from BelleDec 06 2007We report on recent measurements of the $D^0-\bar{D}^0$ mixing and $CP$ violation parameters performed by the Belle experiment. The evidence for the mixing phenomena in the system of neutral $D$ mesons, arising in the study of $D^0\to K^+K^-, \pi^+\pi^-$ ... More
Vogan diagrams of Affine Kac-Moody SuperalgebrasSep 05 2012Sep 06 2012This article classifies the Vogan diagram of the affine untwisted Kac Moody superalgebras.
Measuring mass and angular momentum of black holes with high-frequency quasi-periodic oscillationsJun 24 20043:2 and/or 3:1 twin high frequency quasi-periodic oscillations (HFQPOs) have been measured for the three microquasars GRO J1655-40, XTE J1550-564 and GRS 1915+105. For a test particle orbiting a rotating black on a stable circular orbit there exist two ... More
Unified dispersive approach to real and virtual photon-photon scattering at low energyMay 14 2013Aug 13 2013Previous representations of pion pair production amplitudes by two real photons at low energy, which combine dispersion theoretical constraints with elastic unitariy, chiral symmetry and soft photon constraints are generalized to the case where one photon ... More
A sum rule approach to the violation of Dashen's theoremJan 28 1997Jun 18 1997A classic sum rule by Das et al. is extended to seven of the low-energy constants $K_i$, introduced by Urech, which parameterize electromagnetic corrections at chiral order $O(e^2p^2)$. Using the spurion formalism, a simple convolution representation ... More
On the Drinfeld generators of grt_1(k) and Gamma-functions for associatorsFeb 04 2005We prove that the Drinfeld generators of grt_1(k) span the image of this Lie algebra in the abelianization of the commutator of the free Lie algebra with two generators. We show that this result implies Gamma-function formulas for arbitrary associators. ... More
Dynamical $r$-matrices for Hitchin's systems on Schottky curvesJul 15 1997We express Hitchin's systems on curves in Schottky parametrization, and construct dynamical $r$-matrices attached to them.
A cohomological construction of quantization functors of Lie bialgebrasDec 23 2002We propose a variant to the Etingof-Kazhdan construction of quantization functors. We construct the twistor J_\Phi associated to an associator \Phi using cohomological techniques. We then introduce a criterion ensuring that the ``left Hopf algebra'' of ... More
Quantum currents realization of the elliptic quantum groups $E_{τ,η}({\frak{sl}}_{2})$Sep 11 1997We review the construction by G. Felder and the author of the realization of the elliptic quantum groups of sl(2)-type by quantum currents.
Local unitary equivalence of multipartite pure statesSep 28 2009Necessary and sufficient conditions for the equivalence of arbitrary n-qubit pure quantum states under Local Unitary (LU) operations are derived. First, an easily computable standard form for multipartite states is introduced. Two generic states are shown ... More
Asymptotics of skew orthogonal polynomialsDec 04 2000Exact integral expressions of the skew orthogonal polynomials involved in Orthogonal (beta=1) and Symplectic (beta=4) random matrix ensembles are obtained: the (even rank) skew orthogonal polynomials are average characteristic polynomials of random matrices. ... More
Born-Infeld Corrections to the Entropy Function of Heterotic Black HolesApr 05 2006Jul 03 2006We use the black hole entropy function to study the effect of Born-Infeld terms on the entropy of extremal black holes in heterotic string theory in four dimensions. We find that after adding a set of higher curvature terms to the effective action, attractor ... More
Intersection numbers of spectral curvesApr 01 2011Jun 09 2011We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined ... More
The Masses of Nearby Dwarfs can be Determined with Gravitational MicrolensingApr 27 1995Microlensing of distant stars in the Milky Way by the nearby high proper motion stars offers a direct way to precisely measure the masses of single lower main sequence stars and brown dwarfs.
Distinguishing scalar from pseudoscalar Higgs production at the LHCAug 29 2002Oct 17 2002In this letter we examine the production channels for the scalar or pseudoscalar Higgs plus two jets at the CERN Large Hadron Collider (LHC). We identify possible signals for distinguishing between a scalar and a pseudoscalar Higgs boson.
Failure of the Generalized Eigenstate Thermalization Hypothesis in integrable models with multiple particle speciesJun 18 2014Aug 21 2014It has been recently observed for a particular quantum quench in the XXZ spin chain that local observables do not equilibrate to the predictions of the Generalized Gibbs Ensemble (GGE). In this work we argue that the breakdown of the GGE can be attributed ... More
On O(1) contributions to the free energy in Bethe Ansatz systems: the exact g-functionMar 29 2010Jul 22 2010We investigate the sub-leading contributions to the free energy of Bethe Ansatz solvable (continuum) models with different boundary conditions. We show that the Thermodynamic Bethe Ansatz approach is capable of providing the O(1) pieces if both the density ... More
A new version of homotopical HausdorffApr 05 2011Mar 04 2013It is known that shape injectivity implies homotopical Hausdorff and that the converse does not hold, even if the space is required to be a Peano continuum. This paper gives an alternative definition of homotopical Hausdorff inspired by a new topology ... More
Thread bonds in moleculesJan 04 2015Unusual chemical bonds are proposed. Each bond is almost covalent but is characterized by the thread of a small radius $\sim 0.6\times 10^{-11}$cm, between two nuclei in a molecule. The main electron density is concentrated outside the thread as in a ... More
Two-dimensional tunneling in a SQUIDApr 07 2010Traditionally quantum tunneling in a static SQUID is studied on the basis of a classical trajectory in imaginary time under a two-dimensional potential barrier. The trajectory connects a potential well and an outer region crossing their borders in perpendicular ... More
Euclidean resonance in a magnetic fieldMay 19 2007An analogy between Wigner resonant tunneling and tunneling across a static potential barrier in a static magnetic field is found. Whereas in the process of Wigner tunneling an electron encounters a classically allowed regions, where a discrete energy ... More
Nuclear threadsDec 20 2013Nov 30 2014The internal structure of deuterons weakly influences a motion of their center of mass (translational motion). The scenario can be different when the translational wave function has a formal singularity along the line (thread) connecting the deuteron ... More
Mapping of Euclidean resonance on static resonant tunnelingJul 20 2004Quantum tunneling through an almost classical potential barrier can be strongly enhanced by a nonstationary field so that the penetration through the barrier becomes not exponentially small. This constitutes an extremely unusual phenomenon of quantum ... More
Crossover, Fluctuations and Anderson Transition in Quark Matter FormationOct 03 2006We argue that there is a unique transition state of moderate density between the nuclear matter and superconducting quark matter alternatives. The distinguishing features of this state are discussed.
Remark on the effective range approach to the f_0-a_0 mesonsFeb 02 2004Jun 24 2004Discussion of apparently simple issues related to the resonance close to threshold may lead to misleading results. We clarify some subtle points, in particular the relation between Breit-Wigner and effective range approaches to the f_0-a_0 mesons.
Unusual condensates in quark and atomic systemsOct 22 2005Oct 31 2005In these lectures we discuss condensates which are formed in quark matter when it is squeezed and in a gas of fermionic atoms when it is cooled. The behavior of these two seemingly very different systems reveals striking similarities. In particular, in ... More
Scaling laws prediction from a solvable model of turbulent thermal convectionJun 09 2011A solvable turbulent model is used to predict both the structure of the boundary layer and the scaling laws in thermal convection. The transport of heat depends on the interplay between the thermal, viscous and integral scales of turbulence, and thus, ... More
Logarithmic corrections to scaling in turbulent thermal convectionJan 04 2001We use an analytic toy model of turbulent convection to show that most of the scaling regimes are spoiled by logarithmic corrections, in a way consistent with the most accurate experimental measurements available nowadays. This sets a need for the search ... More
Quantum and classical features in the explanation of collisional decoherenceDec 16 2003A most simple theoretical argument is given in order to explain the quantitative estimate of the effect of collisional decoherence in matter-wave interferometry. The argument highlights the relevance of quantum and classical features in the description ... More
Complete positivity and subdynamics in quantum field theoryNov 20 2002The relevance that the property of complete positivity has had in the determination of quantum structures is briefly reviewed, together with recent applications to neutron optics and quantum Brownian motion. A possible useful application and generalization ... More
Next-to-leading order QCD corrections to photon production via weak-boson fusionApr 06 2010We present a calculation of next-to-leading order QCD corrections to gamma jj production via weak-boson fusion at a hadron collider in the form of a flexible parton-level Monte Carlo program which allows us to study cross sections and distributions within ... More
Loop Variables and Gauge Invariant Exact Renormalization Group Equations for (Open) String TheoryFeb 20 2012Feb 27 2012An exact renormalization group equation is written down for the world sheet theory describing the bosonic open string in general backgrounds. Loop variable techniques are used to make the equation gauge invariant. This is worked out explicitly up to level ... More
Action for (Free) Open String Modes in AdS Space Using the Loop Variable ApproachDec 08 2006The loop variable technique (for open strings in flat space) is a gauge invariant generalization of the renormalization group method for obtaining equations of motion. Unlike the beta functions, which are only proportional to the equations of motion, ... More
Loop Variables and the Interacting Open String in a Curved BackgroundMar 01 2005Applying the loop variable proposal to a sigma model (with boundary) in a curved target space, we give a systematic method for writing the gauge and generally covariant interacting equations of motion for the modes of the open string in a curved background. ... More
Fundamental Strings and D-strings in the IIB Matrix ModelMar 19 1997Mar 29 1997The matrix model for IIB Superstring proposed by Ishibashi, Kawai, Kitazawa and Tsuchiya is investigated. Consideration of planar and non-planar diagrams suggests that the large N perturbative expansion is consistent with the double scaling limit proposed ... More
Some Issues In The Loop Variable Approach to Open Strings and an Extension to Closed StringsJul 14 1993Some issues in the loop variable renormalization group approach to gauge invariant equations for the free fields of the open string are discussed. It had been shown in an earlier paper that this leads to a simple form of the gauge transformation law. ... More
Loop Variables and the Virasoro GroupJul 14 1992We derive an expression in closed form for the action of a finite element of the Virasoro Group on generalized vertex operators. This complements earlier results giving an algorithm to compute the action of a finite string of generators of the Virasoro ... More
Loop Variables in String TheoryJul 11 2002The loop variable approach is a proposal for a gauge invariant generalization of the sigma-model renormalization group method of obtaining equations of motion in string theory. The basic guiding principle is space-time gauge invariance rather than world-sheet ... More
Loop Variables and Gauge Invariant Interactions - IFeb 17 2000Jul 26 2000We describe a method of writing down interacting equations for all the modes of the bosonic open string. It is a generalization of the loop variable approach that was used earlier for the free, and lowest order interacting cases. The generalization involves, ... More
Evidence for low freeze-out temperature and large transverse flow in central collisions of Pb + Pb at 158 AGeVDec 12 1996Utilizing a hydrodynamical model for the freeze-out stage in heavy-ion reactions, we extract from resolved transverse hadron spectra at midrapidity an inverse slope parameter (temperature) $T_{Pb} =$ 120 MeV and an averaged transverse flow velocity $v_{\perp ... More
From known to undiscovered resonancesMay 02 2001Electromagnetic meson production formalisms are reviewed, with emphasise placed on their ability in search for new baryon resonances via gamma p -> K+ Lambda and gamma p -> eta p processes. The relevant studies, aiming to deepen our insights to hadron ... More
Mesons electromagnetic production study via a constituent quark approachApr 30 2001Using a chiral constituent quark approach based on the broken SU(6) \otimes O(3) symmetry, we focus on the spectroscopy of isospin-1/2 nucleonic resonances. A model for the eta photoproduction, embodying all known nucleonic resonances, shows clear need ... More
Bose-Einstein Correlations for Expanding Finite Systems or from a Hot Fireball to a Snow-FlurrySep 04 1995Most boson emitting sources contain a core of finite dimensions surrounded by a large halo, due to long-lived resonances like $\omega,\eta,\eta',K^{0}$ etc. When the Bose-Einstein correlation (BEC) function of the core can be determined we show that its ... More
Large N and Bethe ansatzNov 26 2003Jul 05 2004We describe an integrable model, related to the Gaudin magnet, and its relation to the matrix model of Brezin, Itzykson, Parisi and Zuber. Relation is based on Bethe ansatz for the integrable model and its interpretation using orthogonal polynomials and ... More
Motivations and Physical Aims of Algebraic QFTAug 13 1996Sep 17 1996We present illustrations which show the usefulness of algebraic QFT. In particular in low-dimensional QFT, when Lagrangian quantization does not exist or is useless (e.g. in chiral conformal theories), the algebraic method is beginning to reveal its strength. ... More
Modular Theory and Symmetry in QFTOct 11 1993Oct 27 1993The application of the Tomita-Takesaki modular theory to the Haag-Kastler net approach in QFT yields external (space-time) symmetries as well as internal ones (internal ``gauge para-groups") and their dual counterparts (the ``super selection para-group"). ... More
Existence of close pseudoholomorphic disks for almost complex manifolds and an applications to Kobayashi-Royden pseudonormFeb 23 2000In this paper we extend the notion of the Kobayashi-Royden pseudonorm for almost complex manifolds. Its basic properties known from the complex analysis are preserved in the nonintegrable case as well. The main theorem on coincidence of the pseudodistance ... More
Experimental signals of the first phase transition of nuclear matterFeb 26 2001Vaporized and multifragmenting sources produced in heavy ion collisions at intermediate energies are good candidates to investigate the phase diagram of nuclear matter. The properties of highly excited nuclear sources which undergo a simultaneous disassembly ... More
Canonical approach to 2D WZNW model, non-abelian bosonization and anomaliesDec 22 1999The gauged WZNW model has been derived as an effective action, whose Poisson bracket algebra of the constraints is isomorphic to the commutator algebra of operators in quantized fermionic theory. As a consequence, the hamiltonian as well as usual lagrangian ... More
CHIRAL SYMMETRIES OF THE WZNW MODEL BY HAMILTONIAN METHODSMar 22 1995The connection between the Kac-Moody algebras of currents and the chiral symmetries of the two dimensional WZNW model is clarified. It is shown that only the zero modes of the Kac-Moody currents are the first class constraints, and that, consequently, ... More
Density waves in the shearing sheet I. Swing amplificationDec 21 2000Mar 02 2001The shearing sheet model of a galactic disk is studied anew. The theoretical description of its dynamics is based on three building blocks: Stellar orbits, which are described here in epicyclic approximation, the collisionless Boltzmann equation determining ... More
NGC2613, 3198, 6503, 7184: Case studies against `maximum' disksDec 02 1998Decompositions of the rotation curves of NGC2613, 3198, 6505, and 7184 are analysed. For these galaxies the radial velocity dispersions of the stars have been measured and their morphology is clearly discernible. If the parameters of the decompositions ... More
The role of an accretion disk in AGN variabilitySep 10 2004Optically thick accretion disks are considered to be important ingredients of luminous AGN. The claim of their existence is well supported by observations and recent years brought some progress in understanding of their dynamics. However, the role of ... More
Origin of the Thermal Radiation in a Solid-State Analog of a Black-HoleMar 26 1997An effective black-hole-like horizon occurs, for electromagnetic waves in matter, at a surface of singular electric and magnetic permeabilities. In a physical dispersive medium this horizon disappears for wave numbers with $k>k_c$. Nevertheless, it is ... More
Weak-Coupling Instabilities of Two-Dimensional Lattice ElectronsJul 02 2002In this thesis, I study a two-dimensional extended Hubbard model in the weak coupling limit. Quite generally, the electron gas is unstable towards a superconducting state even in the absence of phonons. However in the special case of a half-filled band, ... More
Homotopical finiteness of smooth and proper dg-algebrasSep 27 2006Aug 02 2007We show that any smooth and proper dg-algebra (over some base ring k) is determined, up to quasi-isomorphism, by its underlying A_n-algebra, for a certain integer n. Similarly, any morphism between two smooth and proper dg-algebras is determined, up to ... More
Riemann-Roch Theorems for Deligne-Mumford StacksMar 17 1998Mar 18 1998The goal of this paper is to prove Riemann-Roch type theorems for Deligne-Mumford algebraic stacks. To this end, we introduce a "cohomology with coefficients in representations" and a Chern character, and we prove a Grothendieck-Riemann-Roch theorem for ... More
Towards an axiomatization of the theory of higher categoriesSep 30 2004Mar 18 2005We define a notion of "theory of (1,infty)-categories", and we prove that such a theory is unique up to equivalence.
Monte Carlo simulations and numerical solutions of short-time critical dynamicsOct 30 1999Recent progress in numerical study of the short-time critical dynamics is briefly reviewed.
The mass quantum and black hole entropy IIJan 15 2001In gr-qc/9908036 [Phys. Lett. A 265 (2000) 1] a new method was given which naturally led to a quantum of mass equal to twice the Planck mass. In the present note which, for convenience, we write formally as a continuation of that paper, we show that with ... More
Large N flavor beta-functions: a recapJun 10 2010Oct 20 2010$\beta$-functions for abelian and non-abelian gauge theories are studied in the regime where the large $N$ flavor expansion is applicable. The first nontrivial order in the 1/$N$ expansion is known for any value of $N\alpha$, and there are also various ... More
Dpes massless QCD have vacuum energy?Aug 08 2007May 14 2008It is widely thought that this question has a positive answer, but we argue that the support for this belief from both experiment and theory is weak or nonexistent. We then list some of the ramifications of a negative answer.
Hints of New Flavor Physics at LEP?Jul 17 1994Sep 29 1994A massive gauge boson coupling to the third family but not lighter families mixes with the $Z$. The $Z$ partial width to $b\overline{b}$ increases, the $\tau$ asymmetry parameter increases, the invisible width of the $Z$ decreases, and $\alpha_s(m_Z)$ ... More
Cosmic balloonsJul 28 1993Dec 21 1993Cosmic balloons, consisting of relativistic particles trapped inside a spherical domain wall, may be created in the early universe. We calculate the balloon mass $M$ as a function of the radius $R$ and the energy density profile, $\rho (r)$, including ... More
Revisiting $HW\rightarrowγγ\ellν$Jun 27 2012Sep 30 2012A new particle of mass around 125 GeV is known to have loop induced couplings to $gg$ and $\gamma\gamma$. More specific to the Higgs interpretation are tree level couplings to $W$ and $Z$. A small but clean signal of the Higgs coupling to $W$ arises from ... More
Gribov copies and topological chargeMar 29 2010Nov 03 2010The existence of Gribov copies is a central feature of the field configuration space of confining gauge theories. In particular a transition between two Gribov copies with relative winding number implies a space-time configuration with topological charge. ... More
The discovery of the fourth family at the LHC: what if?Jun 13 2006Aug 25 2006The first evidence of new strong interactions may be a sufficiently massive fourth family observed at the LHC. The fourth family masses, of the leptons in particular, are constrained by the electroweak precision data, and this leads to signatures at the ... More
The size of flavor changing effects induced by the symmetry breaking sectorJun 11 1997It has recently been shown that strong interactions underlying electroweak symmetry breaking will induce four-fermion amplitudes proportional to m_t^2, which in turn will influence a variety of flavor changing processes. We argue that the size of these ... More
Are Four-Fermion Operators Relevant for the Fermion Mass Problem?Dec 13 1995Apr 26 1996Four-fermion operators may have large anomalous scaling and become relevant operators in some strongly interacting gauge theories. We present a detailed model which illustrates some of the implications of such operators for the generation of quark and ... More
Multicolored quantum dimer models, resonating valence-bond states, color visons, and the triangular-lattice t_2g spin-orbital systemSep 27 2010The spin-orbital model for triply degenerate t_2g electrons on a triangular lattice has been shown to be dominated by dimers: the phase diagram contains both strongly resonating, compound spin-orbital dimer states and quasi-static, spin-singlet valence-bond ... More
The electric dipole moment of the neutron in chiral perturbation theoryApr 03 2000We calculate the electric dipole moments of the neutron and the Lambda within the framework of heavy baryon chiral perturbation theory. They are induced by strong CP-violating terms of the effective Lagrangian in the presence of the vacuum angle theta_0. ... More