Results for "Evan Berkowitz"

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Supergravity from Gauge TheoryAug 05 2016Gauge/gravity duality is the conjecture that string theories have dual descriptions as gauge theories. Weakly-coupled gravity is dual to strongly-coupled gauge theories, ideal for lattice calculations. I will show precision lattice calculations that confirm ... More
Lattice QCD and Axion CosmologySep 09 2015The Strong CP Problem can be resolved by introducing an additional global symmetry known as Peccei-Quinn symmetry. Once PQ symmetry is broken the associated particle, the QCD axion, is a plausible dark matter candidate. Calculating the cosmological energy ... More
Gauged And Ungauged: A Nonperturbative TestFeb 08 2018We study the thermodynamics of the `ungauged' D0-brane matrix model by Monte Carlo simulation. Our results appear to be consistent with the conjecture by Maldacena and Milekhin.
Chaos in Matrix Models and Black Hole EvaporationFeb 03 2016Mar 17 2016Is the evaporation of a black hole described by a unitary theory? In order to shed light on this question ---especially aspects of this question such as a black hole's negative specific heat---we consider the real-time dynamics of a solitonic object in ... More
Multi-channel S-matrices from energy levels in finite boxesNov 09 2012Mar 06 2013We show that for a generic quantum mechanical system with more than one open scattering channel, it is not possible to fully reconstruct the theory's S-matrix from spectral information obtained in large finite volumes with periodic boundary conditions. ... More
A microscopic description of black hole evaporation via holographyMar 09 2016Jul 03 2016We propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically ... More
Stable vortex loops in two-species BECsNov 18 2011We consider the creation of stable, stationary closed vortex loops, analogue to the vortons and superconducting cosmic strings, in cold atom BEC's. We explore the parameter region where these solutions are likely to exist and comment on methods to create ... More
Neutrino Emission from Helium White Dwarfs with Condensed CoresMar 05 2012The possibility that ions in a helium white dwarf star are in a Bose-Einstein condensed state has been explored recently. In particular, it has been argued that the resulting novel quantum liquid has a new kind of quasiparticle excitation with a phonon-like ... More
Lattice QCD input for axion cosmologyMay 27 2015One intriguing BSM particle is the QCD axion, which could simultaneously provide a solution to the Strong CP problem and account for some, if not all, of the dark matter density in the universe. This particle is a pNGB of the conjectured Peccei-Quinn ... More
Nuclear condensate and helium white dwarfsNov 05 2011We consider a high density region of the helium phase diagram, where the nuclei form a Bose-Einstein condensate rather than a classical plasma or a crystal. Helium in this phase may be present in helium-core white dwarfs. We show that in this regime there ... More
Thermodynamics of nuclear condensates and phase transitions in white dwarfsJun 05 2012We study the thermodynamics of helium at densities relevant for white dwarf physics. We find evidence that, as the temperature is increased, there is first a first order transition between two superconducting phases followed by a second order transition ... More
Vortons in dense quark matterFeb 23 2011Feb 24 2011At large baryon number density, it is likely that the ground state of QCD is a color-flavor-locked phase with a K0 condensate. The CFL+K0 phase is known to support superconducting vortex strings, and it has been previously suggested that it may also support ... More
Electron shielding of vortons in high-density quark matterDec 06 2011We consider the the effect of the electron cloud about a vorton in the CFL-$K^0$ high-density phase by numerically solving the ultrarelativistic Thomas-Fermi equation about a toroidal charge. Including electrons removes the electric monopole contribution ... More
Nuclear Parity Violation from Lattice QCDNov 06 2015The electroweak interaction at the level of quarks and gluons are well understood from precision measurements in high energy collider experiments. Relating these fundamental parameters to Hadronic Parity Violation in nuclei however remains an outstanding ... More
Precision lattice test of the gauge/gravity duality at large-$N$Jun 15 2016We pioneer a systematic, large-scale lattice simulation of D0-brane quantum mechanics. The large-$N$ and continuum limits of the gauge theory are taken for the first time at various temperatures $0.4 \leq T \leq 1.0$. As a way to directly test the gauge/gravity ... More
Supergravity from D0-brane Quantum MechanicsJun 15 2016The gauge/gravity duality conjecture claims the equivalence between gauge theory and superstring/M-theory. In particular, the one-dimensional gauge theory of D0-branes and type IIA string theory should agree on properties of hot black holes. Type IIA ... More
A Quantitative Local Limit Theorem for Triangles in Random GraphsOct 05 2016Oct 25 2016In this paper we prove a quantiative local limit theorem for the distribution of the number of triangles in the Erd\H{o}s-Renyi random graph $G(n,p)$, for a fixed $p\in (0,1)$. This proof is an extension of the previous work of Gilmer and Kopparty, who ... More
A Quantitative Local Limit Theorem for Triangles in Random GraphsOct 05 2016In this paper we prove a quantiative local limit theorem for the distribution of the number of triangles in the Erd\H{o}s-Renyi random graph $G(n,p)$, for a fixed $p\in (0,1)$. This proof is an extension of the previous work of Gilmer and Kopparty, who ... More
Two-Nucleon Higher Partial-Wave Scattering from Lattice QCDAug 04 2015We present a determination of nucleon-nucleon scattering phase shifts for l>=0. The S,P,D and F phase shifts for both the spin-triplet and spin-singlet channels are computed for the first time with lattice Quantum ChromoDynamics. This required the design ... More
Two-nucleon scattering in multiple partial wavesNov 06 2015We determine scattering phase shifts for S,P,D, and F partial wave channels in two-nucleon systems using lattice QCD methods. We use a generalization of Luscher's finite volume method to determine infinite volume phase shifts from a set of finite volume ... More
Neutrinoless double beta decay from lattice QCDAug 16 2016While the discovery of non-zero neutrino masses is one of the most important accomplishments by physicists in the past century, it is still unknown how and in what form these masses arise. Lepton number-violating neutrinoless double beta decay is a natural ... More
A stability result using the matrix norm to bound the permanentJun 23 2016We prove a stability version of a general result that bounds the permanent of a matrix in terms of its operator norm. More specifically, suppose $A$ is an $n \times n$ matrix over $\mathbb{C}$ (resp. $\mathbb{R}$), and let $\mathcal{P}$ denote the set ... More
Molecular Dynamics Simulation Study of Interaction between Model Rough Hydrophobic SurfacesJun 01 2011We study some aspects of hydrophobic interaction between molecular rough and flexible model surfaces. The model we use in this work is based on a model we used previously (Eun, C.; Berkowitz, M. L. J. Phys. Chem. B 2009, 113, 13222-13228), when we studied ... More
Strong Extended Technicolour Interactions and the $Zb\bar{b}$ VertexMar 21 1994LEP precision measurements of the $Zb\bar{b}$ vertex coupling are sufficiently accurate to see the non-oblique corrections from the heavy gauge boson responsible for the large top mass in standard extended tecnicolour models. If the ETC couplings are ... More
V,W and X in Technicolour ModelsNov 30 1993Light techni-fermions and pseudo Goldstone bosons that contribute to the electroweak radiative correction parameters V,W and X may relax the constraints on technicolour models from the experimental values of the parameters S and T. Order of magnitude ... More
What Can the Distribution of Intergalactic Metals Tell us About the History of Cosmological Enrichment?Apr 04 2005I study the relationship between the spatial distribution of intergalactic metals and the masses and ejection energies of the sources that produced them. Over a wide range of models, metal enrichment is dominated by the smallest efficient sources, as ... More
Non-Equilibrium Steady States in Kac's Model Coupled to a ThermostatMar 29 2016This paper studies the existence, uniqueness and convergence to non-equilibrium steady states in Kac's model with an external coupling. We work in both Fourier distances and Wasserstein distances. Our methods work in the case where the external coupling ... More
Linear polychromatic colorings of hypercube facesSep 05 2016A coloring of the $\ell$-dimensional faces of $Q_n$ is called $d$-polychromatic if every embedded $Q_d$ has every color on at least one face. Denote by $p_d^\ell$ the maximum number of colors such that any $Q_n$ can be colored in this way. We provide ... More
Duality in Non-Supersymmetric MQCDApr 14 1998Apr 30 1998The curves that describe the M-theoretic extension of type IIA string configurations with non-supersymmetric field theories on their surface exhibit a duality map. The map suggests a continued link between a SU(N) gauge theory with F flavours and an SU(F-N) ... More
Microlensing, or Galactic TwinklingNov 20 1996Microlensing has established itself as a powerful new method for the detection of baryonic dark matter in the Galaxy. The theory of microlensing is sketched and its similarity with the optical effect of twinkling is explained. The bulk of the article ... More
Coexistence of Scale-Invariant States in Incompressible ElastomersFeb 25 2013Nov 01 2013Cavitation and sulcification of soft elastomers are two examples of thresholdless, nonlinear instabilities that evade detection by linearization. I show that the onset of such instabilities can be understood as a kind of phase coexistence between multiple ... More
The current status of neutrino mixingJul 19 2011A brief review of the experimental status of neutrino mixing. The model of neutrino oscillations has now been established with high confidence, with many of the model parameters measured to an accuracy of a few per cent. However, some parameters still ... More
Combinatorial Sutured TQFT as Exterior AlgebraSep 30 2012The idea of a sutured topological quantum field theory was introduced by Honda, Kazez and Mati\'c (2008). A sutured TQFT associates a group to each sutured surface and an element of this group to each dividing set on this surface. The notion was originally ... More
On the twisted Floer homology of mapping tori of periodic diffeomorphismsOct 12 2009Let K \subset Y be a knot in a three manifold which admits a longitude-framed surgery such that the surgered manifold has first Betti number greater than that of Y. We find a formula which computes the twisted Floer homology of the surgered manifold, ... More
Renormalization Group Flows In The Deformed AdS/CFT CorrespondenceDec 12 2000Dec 21 2000In the AdS/CFT correspondence motion in the radial direction of the AdS space is identified with renormalization group flow in the field theory. For the N=4 Yang-Mills theory this motion is trivial. More interesting examples of renormalization group flow ... More
Decoupling Dynamical Electroweak Symmetry BreakingOct 15 1999The modern precision accelerator data has essentially ruled out the most obvious model of dynamical electroweak symmetry breaking, technicolour. The idea is though well motivated and it is important to construct models compatible with the precision data ... More
QCD Dynamics From M-TheoryMay 10 1998The field theories on the surface of non-supersymmetric D-brane constructions are identified. By moving to M-theory a semi-classical, strong coupling expansion to the IR non-supersymmetric gauge dynamics is obtained. The solution is consistent with the ... More
Softly Broken SQCD: in the Continuum, on the Lattice, on the BraneJul 23 1997Jul 28 1997We review progress in studying the solutions of SQCD in the presence of explicit, soft SUSY breaking terms. Massive N=1 SQCD in the presence of a small gaugino mass leads to a controlled solution which has interesting phase structure with changing theta ... More
Rapidly computable viscous friction and no-slip rigid contact modelsApr 03 2015This article presents computationally efficient algorithms for modeling two special cases of rigid contact---contact with only viscous friction and contact without slip---that have particularly useful applications in robotic locomotion and grasping. Modeling ... More
Strongly Intensive Cumulants: Fluctuation Measures for Systems With Incompletely Constrained VolumesMay 01 2015Sep 04 2015The cumulants of thermal variables are of general interest in physics due to their extensivity and their correspondence with susceptibilities. They become especially significant near critical points of phase transitions where they diverge along with the ... More
Pair-Production Supernovae: Theory and ObservationSep 07 2006Sep 24 2006I review the physical properties of pair-production supernovae (PPSNe) as well as the prospects for them to be constrained observationally. In very massive (140-260 solar mass) stars, much of the pressure support comes from the radiation field, meaning ... More
Is There a Detectable Vishniac Effect?Feb 08 2000The dominant linear contribution to cosmic microwave background (CMB) fluctuations at small angular scales (less than one arcsec) is a second-order contribution known as the Vishniac or Ostriker-Vishniac effect. This effect is caused by the scattering ... More
Additional Fermion Families and Precision Electroweak DataAug 17 1994The S,T, and U formalism for studying electroweak precision data has recently been updated to include the effects of new light physics and within this analysis the latest LEP and SLC data tightly constrain models of physics beyond the Standard Model. ... More
Quark Condensates in Non-Supersymmetric MQCDJan 23 1998Jun 14 1998A set of non-supersymmetric minimal area embeddings of an M-theory 5-brane are considered. The field theories on the surface of the 5-brane have the field content of N=2 SQCD with fundamental representation matter fields. By suitable choice of curve parameters ... More
Dynamical Generation of the CKM MatrixOct 07 1994We argue that in dynamical models of fermion masses, which explain the three mass scales of the generations of fermions with three separate heavy scales above the electroweak symmetry breaking scale, the off diagonal CKM matrix elements must be generated ... More
Fermion Mass Postdictions in a Generalized Extended Technicolour ScenarioMay 23 1994We review the recent discussion in the literature of one family extended technicolour models with techni-fermion mass spectra compatible with the experimental data for the precision parameters S,T,U,V, W and X and ETC interactions compatible with the ... More
Comment on Cowsik et al.'s "The Dispersion Velocity of Galactic Dark Matter Particles"Jun 25 1996Sep 06 1996In a recent Letter (astro-ph/9605001), Cowsik et al. claim that the best fit value of the velocity dispersion of the Galactic dark matter is 600 kms. This result is obtained by a numerical method of solving the coupled self-gravitation equations, assuming ... More
Time Evolution of Temperature and Entropy of Various Collapsing Domain WallsJun 12 2011Sep 10 2012We investigate the time evolution of the temperature and entropy of gravitationally collapsing domain walls as seen by an asymptotic observer. In particular, we seek to understand how topology and the addition of a cosmological constant affect the gravitational ... More
Critical Population Size for Branching Process Approximation of Probability of Disease ExtinctionNov 14 2016Deterministicmodelstostudythedynamicsofinfectiousdiseaseshavebeenan effective tool for prediction of the persistence of infection. The basic reproduction number R0 has been shown to be a threshold in such models with R0 > 1 a sufficient condition for ... More
Avoiding algebraic integers of bounded house in orbits of rational functions over cyclotomic closuresAug 14 2016Let $k$ be a number field with cyclotomic closure $k^{\mathrm{cyc}}$, and let $h \in k^{\mathrm{cyc}}(x)$. For $A \ge 1$ a real number, we show that \[ \{ \alpha \in k^{\mathrm{cyc}} : h(\alpha) \in \overline{\mathbb Z} \text{ has house at most } A \} ... More
Understanding Galaxy Outflows as the Product of Unstable Turbulent SupportFeb 14 2013The interstellar medium is a multiphase gas in which turbulent support is as important as thermal pressure. Sustaining this configuration requires both continuous turbulent stirring and continuous radiative cooling to match the decay of turbulent energy. ... More
FERMION MASSES IN EXTENDED TECHNICOLOURJan 16 1995Talks presented at Beyond The Standard Model IV Conference, Lake Tahoe, Dec 94: NEW FERMION FAMILIES AND PRECISION ELECTROWEAK DATA: We highlight a trend in the precision electroweak data towards light new physics and argue that some spectra of strongly ... More
Extensions of groups by braided 2-groupsJun 03 2011We classify extensions of a group $G$ by a braided 2-group $\mathcal{B}$ as defined by Drinfeld, Gelaki, Nikshych, and Ostrik. We describe such extensions as homotopy classes of maps from the classifying space of $G$ to the classifying space of the 3-group ... More
Holographic QCD & PerfectionJan 25 2007A holographic description of chiral symmetry breaking in the pattern of QCD is reviewed. D7 brane probes are used to include quark fields in a simple non-supersymmetric deformation of the AdS/CFT Correspondence. The axial symmetry breaking is realized ... More
Effects of Reducing Scaffolding in an Undergraduate Electronics LabJun 27 2016Design and scientific investigation are recognized as key components of undergraduate physics laboratory curricula. In light of this, many successful lab programs have been developed to train students to develop these abilities, and students in these ... More
Strangelets: Who is Looking, and How?May 11 2006It has been over 30 years since the first suggestion that the true ground state of cold hadronic matter might be not nuclear matter but rather strange quark matter (SQM). Ever since, searches for stable SQM have been proceeding in various forms and have ... More
Reinforcement Learning in a Neurally Controlled Robot Using Dopamine Modulated STDPFeb 21 2015Recent work has shown that dopamine-modulated STDP can solve many of the issues associated with reinforcement learning, such as the distal reward problem. Spiking neural networks provide a useful technique in implementing reinforcement learning in an ... More
Direct Detection of Stealth Dark Matter through Electromagnetic PolarizabilityMar 13 2015May 28 2015We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar baryon dark matter candidate -- "Stealth Dark Matter", that is based on a dark SU(4) confining gauge ... More
Composite bosonic baryon dark matter on the lattice: SU(4) baryon spectrum and the effective Higgs interactionFeb 26 2014We present the spectrum of baryons in a new SU(4) gauge theory with fundamental fermion constituents. The spectrum of these bosonic baryons is of significant interest for composite dark matter theories. Here, we compare the spectrum and properties of ... More
A Critical Review of Recurrent Neural Networks for Sequence LearningMay 29 2015Oct 17 2015Countless learning tasks require dealing with sequential data. Image captioning, speech synthesis, and music generation all require that a model produce outputs that are sequences. In other domains, such as time series prediction, video analysis, and ... More
Star Formation in Molecular Clouds?Jun 27 2007Using studies of nearby star formation with Spitzer, I will argue that star formation is restricted to dense cores within molecular clouds. The nature of these dense cores and their connection to star formation will be discussed. Their distribution over ... More
AdS RG-Flow and the Super-Yang-Mills CascadeJun 06 2000We study the 5 dimensional SUGRA AdS duals of N=4, N=2 and N=1 Super-Yang-Mills theories. To sequentially break the N=4 theory mass terms are introduced that correspond, via the duality, to scalar VEVs in the SUGRA. We determine the appropriate scalar ... More
Characterizing Binary Properties of $5\, M_\odot$ Stars: New Approaches Using CepheidsJan 21 2014Cepheids provide approaches to determining binary parameters which are often complementary to those for main sequence massive and intermediate mass stars. Specifically, we are using high resolution imaging, radial velocities, and X-ray studies to determine ... More
Chandrasekhar and Modern Stellar DynamicsFeb 22 2011Stellar dynamics occupied Chandrasekhar's interest for a brief interlude between his more prolonged studies of stellar structure and radiative transfer. This paper traces the history of one of his ideas -- namely, that the shape of the galactic potential ... More
Formation of Compact Stellar Clusters by High-Redshift Galaxy Outflows II: Effect of Turbulence and Metal-Line CoolingMar 22 2011Apr 12 2011In the primordial universe, low mass structures with virial temperatures less than 10$^{4}$ K were unable to cool by atomic line transitions, leading to a strong suppression of star formation. On the other hand, these "minihalos" were highly prone to ... More
On a certain generalization of the Balog-Szemeredi-Gowers TheoremMay 21 2008Jun 25 2008In this note, we prove a certain hypergraph generalization of the Balog-Szemeredi-Gowers Theorem. Our result shares some features in common with a similar such generalizsation due to Sudakov, Szemeredi and Vu, though the conclusion of our result is somewhat ... More
Multi-Agent Modeling Using Intelligent Agents in the Game of LerpaJun 02 2007Game theory has many limitations implicit in its application. By utilizing multiagent modeling, it is possible to solve a number of problems that are unsolvable using traditional game theory. In this paper reinforcement learning is applied to neural networks ... More
The Phase Transition in 5 Point Energy MinimizationOct 11 2016Let R_s(r)=sign(s)/r^s be the Riesz s-energy potential. (This is the usual power-law potential.) This monograph proves the existence of a computable number S=15.048... such that the triangular bi-pyramid is the unique minimizer with respect to R_s, amongst ... More
The Properties of Early-type Stars in the Magellanic CloudsSep 04 2008Sep 15 2008The past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence ... More
T-Duality in Arbitrary String BackgroundsNov 09 1995May 09 1996T-Duality is a poorly understood symmetry of the space-time fields of string theory that interchanges long and short distances. It is best understood in the context of toroidal compactification where, loosely speaking, radii of the torus are inverted. ... More
Deformations, Symmetries and Topological Degrees of Freedom of the StringSep 27 1991We discuss three closely related questions; i)~Given a conformal field theory, how may we deform it? ii)~What are the symmetries of string theory? and iii)~Does string theory have free parameters? We show that there is a distinct deformation of the stress ... More
The Phase Transition in 5 Point Energy MinimizationOct 11 2016Nov 21 2016Let R_s(r)=sign(s)/r^s be the Riesz s-energy potential. (This is the usual power-law potential.) This monograph proves the existence of a computable number S=15.048... such that the triangular bi-pyramid is the unique minimizer with respect to R_s, amongst ... More
Ideal triangle groups, dented tori, and numerical analysisMay 01 2001We prove the Goldman-Parker Conjecture: A complex hyperbolic ideal triangle group is directly embedded in PU(2,1) if and only if the product of its three standard generators is not elliptic. We also prove that such a group is indiscrete if the product ... More
A Custom Support Vector Machine Analysis of the Efficacy of Galaxy Shape Information in Photometric Redshift EstimationJun 30 2016Aug 19 2016Aims: We present a custom support vector machine classification package for photometric redshift estimation, including comparisons with other methods. We also explore the efficacy of the inclusion of galaxy shape information in redshift estimation. Support ... More
Canonical rings of Q-divisors on P^1Jul 17 2014The canonical ring $S_D = \bigoplus_{d \geq 0} H^0(X, \lfloor dD \rfloor)$ of a divisor D on a curve X is a natural object of study; when D is a Q-divisor, it has connections to projective embeddings of stacky curves and rings of modular forms. We study ... More
On Some Generalizations of Fermat's, Lucas's and Wilson's TheoremsOct 28 2005We use actions by finite cyclic groups to derive generalizations of three classical theorems from elementary number theory.
Cohomology of Restricted Lie AlgebrasNov 08 2001In this dissertation, we investigate the cohomology theory of restricted Lie algebras. The representation theory of restricted Lie algebras is reviewed including a description of the restricted universal enveloping algebra. In the case of an abelian restricted ... More
Smart Focal Plane Technologies for VLT InstrumentsJan 19 2008As we move towards the era of ELTs, it is timely to think about the future role of the 8-m class telescopes. Under the OPTICON programme, novel technologies have been developed that are intended for use in multi-object and integral-field spectrographs. ... More
Towards a Deeper Understanding of How Experiments Constrain the Underlying Physics of Heavy-Ion CollisionsAug 27 2015Oct 04 2015Recent work has provided the means to rigorously determine properties of super-hadronic matter from experimental data through the application of broad scale modeling of high-energy nuclear collisions within a Bayesian framework. These studies have provided ... More
A Bound on the Expected Optimality of Random Feasible Solutions to Combinatorial Optimization ProblemsFeb 03 2014This paper investigates and bounds the expected solution quality of combinatorial optimization problems when feasible solutions are chosen at random. Loose general bounds are discovered, as well as families of combinatorial optimization problems for which ... More
Rings of small rank over a Dedekind domain and their idealsAug 11 2015Aug 17 2015In 2001, M. Bhargava stunned the mathematical world by extending Gauss's 200-year-old group law on integral binary quadratic forms, now familiar as the ideal class group of a quadratic ring, to yield group laws on a vast assortment of analogous objects. ... More
Approximating Context-Free Grammars with a Finite-State CalculusNov 11 1997Although adequate models of human language for syntactic analysis and semantic interpretation are of at least context-free complexity, for applications such as speech processing in which speed is important finite-state models are often preferred. These ... More
Fusion rules of modular invariantsApr 23 2002Modular invariants satisfy remarkable fusion rules. Let $Z$ be a modular invariant associated to a braided subfactor $N\subset M$. The decomposition of the non-normalized modular invariants $Z Z^{*}$ and $Z^{*}Z$ into sums of normalized modular invariants ... More
Grids of ATLAS9 Model Atmospheres and MOOG Synthetic SpectraMar 07 2011A grid of ATLAS9 model atmospheres has been computed, spanning 3500 K <= T_eff <= 8000 K, 0.0 <= log g <= 5.0, -4.0 <= [M/H] <= 0.0, and -0.8 < [alpha/Fe] <= +1.2. These parameters are appropriate for stars in the red giant branch, subgiant branch, and ... More
Holographic Modelling of a Light Techni-DilatonFeb 19 2013Mar 26 2013We present a simplified holographic model of chiral symmetry breaking in gauge theory. The chiral condensate is represented by a single scalar field in AdS, with the gauge dynamics input through radial dependence of its mass, representing the running ... More
Symplectic mapping class groups of some Stein and rational surfacesSep 30 2009May 10 2014In this paper we compute the homotopy groups of the symplectomorphism groups of the 3-, 4- and 5-point blow-ups of the projective plane (considered as monotone symplectic Del Pezzo surfaces). Along the way, we need to compute the homotopy groups of the ... More
Lagrangian spheres in Del Pezzo surfacesFeb 03 2009May 03 2010Lagrangian spheres in the symplectic Del Pezzo surfaces arising as blow-ups of the complex projective plane in 4 or fewer points are classified up to Lagrangian isotopy. Unlike the case of the 5-point blow-up, there is no Lagrangian knotting.
Flavors of Supersymmetry Beyond VanillaSep 28 2015This review surveys the territory of supersymmetry beyond the vanilla MSSM. With a viewpoint guided by electroweak naturalness, the review focuses on constructions that weaken or bypass current LHC constraints. Models of SUSY containing Dirac gluinos, ... More
Supersymmetry algebras and Lorentz invariance for d=10 Super Yang-MillsApr 30 1994We consider ways in which conventional supersymmetry can be embedded in the set of more general fermionic transformations proposed recently [\Ref{B}] as a framework in which to study $d=10$ super Yang-Mills. Solutions are exhibited which involve closed ... More
Alternating links and definite surfacesNov 19 2015We establish a characterization of alternating links in terms of definite spanning surfaces. We apply it to obtain a new proof of Tait's conjecture that reduced alternating diagrams of the same link have the same crossing number and writhe. We also deduce ... More
A direct proof of a theorem of Blaschke and LebesgueSep 14 2000The Blaschke-Lebesgue Theorem states that among all planar convex domains of given constant width B the Reuleaux triangle has minimal area. It is the purpose of the present note to give a direct proof of this theorem by analyzing the underlying variational ... More
Expertise revisited I: Interactional ExpertiseNov 14 2016The notion of interactional expertise is explained starting with its origins and discussing its many applications. Interactional expertise is the ability to understand a technical area purely be deeply immersed in its 'practice-language' without actually ... More
Causal Inference through a Witness Protection ProgramJun 02 2014Oct 30 2014One of the most fundamental problems in causal inference is the estimation of a causal effect when variables are confounded. This is difficult in an observational study, because one has no direct evidence that all confounders have been adjusted for. We ... More
Phase Diagrams for Deformable Toroidal and Spherical Surfaces with Intrinsic Orientational OrderOct 03 1994A theoretical study of toroidal membranes with various degrees of intrinsic orientational order is presented at mean-field level. The study uses a simple Ginzburg-Landau style free energy functional, which gives rise to a rich variety of physics and reveals ... More
Perturbative polydispersity: Phase equilibria of near-monodisperse systemsJul 21 2000The conditions of multi-phase equilibrium are solved for generic polydisperse systems. The case of multiple polydispersity is treated, where several properties (e.g. size, charge, shape) simultaneously vary from one particle to another. By developing ... More
Twisted equivariant differential K-theory from gauged supersymmetric mechanicsOct 27 2015We use the geometry of the space of fields for gauged supersymmetric mechanics to construct the twisted differential equivariant K-theory of a manifold with an action by a finite group.
Linking the Metallicity Distribution of Galactic Halo Stars to the Enrichment History of the UniverseDec 07 2000Feb 06 2001We compare the metallicity distribution of Galactic Halo stars with 3D realizations of hierarchical galaxy formation. Outflows from dwarf galaxies enrich the intergalactic medium inhomogeneously, at a rate depending on the local galaxy density. Consequently, ... More
Coherent Photons and Pomerons in Heavy Ion CollisionsJul 03 1997Ultrarelativistic heavy ion beams carry large electromagnetic and strong absorptive fields, allowing exploration of a variety of physics. Two-photon, photon-Pomeron, and double Pomeron interactions can probe a huge variety of couplings and final states. ... More
Inflation from Nilpotent Kähler CorrectionsSep 01 2016We develop a new class of supergravity cosmological models where inflation is induced by terms in the K\"ahler potential which mix a nilpotent superfield $S$ with a chiral sector $\Phi$. As the new terms are non-(anti)holomorphic, and hence cannot be ... More
Microlensing, Brown Dwarfs and GAIASep 05 2014The GAIA satellite can precisely measure the masses of nearby brown dwarfs and lower main sequence stars by the microlensing effect. The scientific yield is maximised if the microlensing event is also followed with ground-based telescopes to provide densely ... More