Results for "John Chisholm"

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The Molecular Baryon Cycle of M82Aug 02 2016Baryons cycle into galaxies from the inter-galactic medium, are converted into stars, and a fraction of the baryons are ejected out of galaxies by stellar feedback. Here we present new high resolution (3.9"; 68 pc) CO(2-1) and CO(3-2) images that probe ... More
Shining A Light On Galactic Outflows: Photo-Ionized OutflowsJan 19 2016We study the ionization structure of galactic outflows in 37 nearby, star forming galaxies with the Cosmic Origins Spectrograph on the Hubble Space Telescope. We use the O I, Si II, Si III, and Si IV ultraviolet absorption lines to characterize the different ... More
Scaling Relations Between Warm Galactic Outflows and Their Host GalaxiesDec 05 2014We report on a sample of 51 nearby, star-forming galaxies observed with the Cosmic Origin Spectrograph on the Hubble Space Telescope. We calculate Si II kinematics and densities arising from warm gas entrained in galactic outflows. We use multi-wavelength ... More
Intense CIV and HeII Emission in z~0 GalaxiesMay 15 2019In the last few years, prominent high-ionization nebular emission lines (i.e., OIII], CIII], CIV, HeII) have been observed in the deep UV spectra of z~5-7 galaxies, indicating that extreme radiation fields characterize reionization-era systems. These ... More
A Mathematical Method for Deriving the Relative Effect of Serviceability on Default RiskNov 23 2011The writers propose a mathematical Method for deriving risk weights which describe how a borrower's income, relative to their debt service obligations (serviceability) affects the probability of default of the loan. The Method considers the borrower's ... More
Hubble captures multiply-imaged ionizing radiation from strongly lensed galaxy at z=2.4Apr 17 2019Apr 18 2019The early Universe was ionized by hard ultraviolet radiation from hot, young stars in the first galaxies. These galaxies contain absorbing neutral Hydrogen which must be configured favorably to allow ionizing escape; only a few dozen cases have been detected ... More
Braid groups and euclidean simplicesNov 04 2014When Daan Krammer and Stephen Bigelow independently proved that braid groups are linear, they used the Lawrence-Krammer-Bigelow representation for generic values of its variables q and t. The t variable is closely connected to the traditional Garside ... More
The Mass and Momentum Outflow Rates of Photoionized Galactic OutflowsFeb 23 2017May 09 2017Galactic outflows are believed to play an important role in regulating star formation in galaxies, but estimates of the outflowing mass and momentum have historically been based on uncertain assumptions. Here, we measure the mass, momentum, and energy ... More
A Robust Measurement of the Mass Outflow Rate of the Galactic Outflow from NGC 6090May 18 2016Aug 01 2016To evaluate the impact of stellar feedback, it is critical to estimate the mass outflow rates of galaxies. Past estimates have been plagued by uncertain assumptions about the outflow geometry, metallicity, and ionization fraction. Here we use Hubble Space ... More
Supernova-Driven Outflows in NGC 7552: A Comparison of H-alpha and UV TracersJul 01 2015We investigate the supernova-driven galactic wind of the barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet absorption lines measured with the Hubble Space Telescope Cosmic Origins Spectrograph. We ... More
Neutral gas properties of Lyman continuum emitting galaxies: column densities and covering fractions from UV absorption linesFeb 18 2018Apr 07 2018The processes allowing the escape of ionizing photons from galaxies into the intergalactic medium are poorly known. To understand how Lyman continuum (LyC) photons escape galaxies, we constrain the HI covering fractions and column densities using ultraviolet ... More
Nanoscale self-templating for oxide epitaxy with large symmetry mismatchSep 26 2016Direct observations using scanning transmission electron microscopy unveil an intriguing interfacial bi-layer that enables epitaxial growth of a strain-free, monoclinic, bronze-phase VO2(B) thin film on a perovskite SrTiO3 (STO) substrate. We observe ... More
The growth of the central region by acquisition of counter-rotating gas in star-forming galaxiesNov 02 2016Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic ... More
Clustering of Primordial Black Holes. II. Evolution of Bound SystemsOct 19 2011Primordial Black Holes (PBHs) that form from the collapse of density perturbations are more clustered than the underlying density field. In a previous paper, we showed the constraints that this has on the prospects of PBH dark matter. In this paper we ... More
Clustering of primordial black holes: Basic resultsSep 06 2005Apr 07 2006We investigate the spatial clustering properties of primordial black holes (PBHs). With minimal assumptions, we show that PBHs created in the radiation era are highly clustered. Using the peaks theory model of bias, we compute the PBH two-point correlation ... More
Constraining the metallicities, ages, star formation histories, and ionizing continua of extragalactic massive star populationsMay 10 2019We infer the properties of massive star populations using the far-ultraviolet stellar continua of 61 star-forming galaxies: 42 at low-z observed with HST and 19 at z~2 from the Megasaura sample. We fit each stellar continuum with a linear combination ... More
The Meaning of Probability of Default for Asset-backed LoansJun 28 2013The authors examine the concept of probability of default for asset-backed loans. In contrast to unsecured loans it is shown that probability of default can be defined as either a measure of the likelihood of the borrower failing to make required payments, ... More
Primordial Black Hole Minimum MassApr 07 2006Aug 16 2006In this paper we revisit thermodynamic constraints on primordial black hole (PBH) formation in the early universe. Under the assumption that PBH mass is equal to the cosmological horizon mass, one can use the 2nd Law of Thermodynamics to put a lower limit ... More
Quantum Critical Behavior in the Asymptotic Limit of High Disorder: Entropy Stabilized NiCoCr0.8 AlloysMay 15 2017The behavior of matter near a quantum critical point (QCP) is one of the most exciting and challenging areas of physics research. Emergent phenomena such as high-temperature superconductivity are linked to the proximity to a QCP. Although significant ... More
Flowdown of the TMT astrometry error budget(s) to the IRIS designAug 04 2016TMT has defined the accuracy to be achieved for both absolute and differential astrometry in its top-level requirements documents. Because of the complexities of different types of astrometric observations, these requirements cannot be used to specify ... More
Selective control of oxygen sublattice stability by epitaxial strain in Ruddlesden-Popper filmsAug 27 2015Oxygen-defect control has long been considered an influential tuning knob for producing various property responses in complex oxide films. In addition to physical property changes, modification to the lattice structure, specifically lattice expansion, ... More
Intense CIII] 1907,1909 emission from a strong Lyman continuum emitting galaxyAug 09 2018We have obtained the first complete ultraviolet (UV) spectrum of a strong Lyman continuum(LyC) emitter at low redshift -- the compact, low-metallicity, star-forming galaxy J1154+2443 -- with a Lyman continuum escape fraction of 46% discovered recently. ... More
The production and escape of ionizing photons from galaxies over cosmic time (Astro2020 Science White Paper)May 14 2019The ionizing photons produced by massive stars are key actors in galaxy evolution. Ionizing photon production and escape is poorly understood. Improved space-based, spatially-resolved, multiplexed spectroscopic capabilities covering observed wavelengths ... More
Astro2020 Science White Paper: Spatially Resolved UV Nebular Diagnostics in Star-Forming GalaxiesMar 15 2019Diagnosing the physical and chemical conditions within star-forming galaxies (SFGs) is of paramount importance to understanding key components of galaxy formation and evolution: star-formation, gas enrichment, outflows, and accretion. Well established ... More
Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen spongeAug 26 2013Fast, reversible redox reactions in solids at low temperatures without thermomechanical degradation are a promising strategy for enhancing the overall performance and lifetime of many energy materials and devices. However, the robust nature of the cation's ... More
Evolution of the Most Massive Galaxies to z=0.6: I. A New Method for Physical Parameter EstimationAug 23 2011Nov 30 2011We use principal component analysis (PCA) to estimate stellar masses, mean stellar ages, star formation histories (SFHs), dust extinctions and stellar velocity dispersions for ~290,000 galaxies with stellar masses greater than $10^{11}Msun and redshifts ... More
Lorentz invariance violation in top-down scenarios of ultrahigh energy cosmic ray creationJun 29 2003Jan 28 2004The violation of Lorentz invariance (LI) has been invoked in a number of ways to explain issues dealing with ultrahigh energy cosmic ray (UHECR) production and propagation. These treatments, however, have mostly been limited to examples in the proton-neutron ... More
Infinitely many knots admitting the same integer surgeryJul 06 2014The construction of knots via annular twisting has been used to create families of knots yielding the same manifold via Dehn surgery. Prior examples have all involved Dehn surgery where the surgery slope is an integral multiple of 2. In this note we prove ... More
Vertex Ramsey problems in the hypercubeNov 01 2012If we 2-color the vertices of a large hypercube what monochromatic substructures are we guaranteed to find? Call a set S of vertices from Q_d, the d-dimensional hypercube, Ramsey if any 2-coloring of the vertices of Q_n, for n sufficiently large, contains ... More
Optimal Bacon-Shor codesSep 04 2012We study the performance of Bacon-Shor codes, quantum subsystem codes which are well suited for applications to fault-tolerant quantum memory because the error syndrome can be extracted by performing two-qubit measurements. Assuming independent noise, ... More
Computing power series expansions of modular formsApr 30 2012Sep 30 2012We exhibit a method to numerically compute power series expansions of modular forms on a cocompact Fuchsian group, using the explicit computation a fundamental domain and linear algebra.
Wavelet decomposition of software entropy reveals symptoms of malicious codeJul 18 2016Sophisticated malware authors can sneak hidden malicious code into portable executable files, and this code can be hard to detect, especially if encrypted or compressed. However, when an executable file switches between code regimes (e.g. native, encrypted, ... More
Observation of a new χ_b state at ATLAS and a new Ξ_b baryon at CMSJul 26 2012Two recent observations of new b hadrons in pp collisions at \sqrt{s} = 7 TeV at the Large Hadron Collider (LHC) are presented. The ATLAS collaboration has observed a new state in radiative transitions to \Upsilon(1S) and \Upsilon(2S) and interprets this ... More
:telephone::person::sailboat::whale::okhand:; or "Call me Ishmael" - How do you translate emoji?Nov 07 2016We report on an exploratory analysis of Emoji Dick, a project that leverages crowdsourcing to translate Melville's Moby Dick into emoji. This distinctive use of emoji removes textual context, and leads to a varying translation quality. In this paper, ... More
Projecting "better than randomly": How to reduce the dimensionality of very large datasets in a way that outperforms random projectionsJan 03 2019For very large datasets, random projections (RP) have become the tool of choice for dimensionality reduction. This is due to the computational complexity of principal component analysis. However, the recent development of randomized principal component ... More
Video Chat with Multiple CamerasSep 06 2012The dominant paradigm for video chat employs a single camera at each end of the conversation, but some conversations can be greatly enhanced by using multiple cameras at one or both ends. This paper provides the first rigorous investigation of multi-camera ... More
Critical Data CompressionDec 23 2011A new approach to data compression is developed and applied to multimedia content. This method separates messages into components suitable for both lossless coding and 'lossy' or statistical coding techniques, compressing complex objects by separately ... More
A geometric answer to an open question of singular control with stoppingSep 28 2015We solve a problem of singular stochastic control with discretionary stopping, suggested as an interesting open problem by Karatzas, Ocone, Wang and Zervos (2000), by providing suitable candidates for the moving boundaries in an unsolved parameter range. ... More
Birth, Death and Flight: A Theory of Malthusian FlocksAug 22 2011Dec 11 2011I study "Malthusian Flocks": moving aggregates of self-propelled entities (e.g., organisms, cytoskeletal actin, microtubules in mitotic spindles) that reproduce and die. Long-ranged order (i.e., the existence of a non-zero average velocity $<\vec v (\vec ... More
The Fast Wandering of Slow BirdsSep 10 2009Oct 21 2011I study a single "slow" bird moving with a flock of birds of a different, and faster (or slower) species. I find that every "species" of flocker has a characteristic speed $\gamma\ne v_0$, where $v_0$ is the mean speed of the flock, such that, if the ... More
Leslie Hodson, particle physicist and pioneer in the study of cosmic rays 1925-2010; Obituary and bibliographyJun 02 2010Leslie Hodson was an experimental particle physicist who developed cloud and spark chamber techniques in the study of cosmic rays. This note reviews his career and provides a bibliography of his publications.
$L^2$-Cohomology of Geometrically Infinite Hyperbolic 3-ManifoldsDec 21 1995We give results on the following questions about a topologically tame hyperbolic 3-manifold M : 1. Does M have nonzero square-integrable harmonic 1-forms? 2. Does zero lie in the spectrum of the Laplacian acting on (1-forms on M)/Ker(d)?
On Macroscopic Complexity and Perceptual CodingMay 10 2010Jul 07 2011The theoretical limits of 'lossy' data compression algorithms are considered. The complexity of an object as seen by a macroscopic observer is the size of the perceptual code which discards all information that can be lost without altering the perception ... More
Rotation Numbers for $S^2$ diffeomorphismsDec 28 2014These largely expository notes describe the properties of the function ${\cal R}$ which assigns a number to a $4$-tuple of distinct fixed points of an orientation preserving homeomorphism or diffeomorphism of $S^2$.
Note on the construction of globular weak omega-groupoids from types, topological spaces etcFeb 25 2016A short introduction to Grothendieck weak omega-groupoids is given. Our aim is to give evidence that, in certain contexts, this simple language is a convenient one for constructing globular weak omega-groupoids. To this end, we give a short reworking ... More
Nonequilibrium Phenomena in Liquid CrystalsMay 21 1993This paper summarizes a talk presented at the April NATO ASI on Spatiotemporal Chaos in Complex Fluids, in Santa Fe, NM. The paper gives reasons that make complex fluids good material systems for conducting experiments on pattern formation and other nonequilibrium ... More
Kramers-Kronig, Bode, and the meaning of zeroJun 30 2011The implications of causality, as captured by the Kramers-Kronig relations between the real and imaginary parts of a linear response function, are familiar parts of the physics curriculum. In 1937, Bode derived a similar relation between the magnitude ... More
Outflows from Massive StarsDec 12 2007The properties of outflows powered by massive stars are reviewed with an emphasis on the nearest examples, Orion and Cepheus-A. The Orion OMC1 outflow may have been powered by the dynamical decay of a non-hierarchical massive star system that resulted ... More
Eclipsing Binary Stars: the Royal Road to Stellar AstrophysicsJan 06 2012Russell (1948) famously described eclipses as the "royal road" to stellar astrophysics. From photometric and spectroscopic observations it is possible to measure the masses and radii (to 1% or better!), and thus surface gravities and mean densities, of ... More
Graph Interpolation Grammars as Context-Free AutomataJul 17 1998A derivation step in a Graph Interpolation Grammar has the effect of scanning an input token. This feature, which aims at emulating the incrementality of the natural parser, restricts the formal power of GIGs. This contrasts with the fact that the derivation ... More
Graph Interpolation Grammars: a Rule-based Approach to the Incremental Parsing of Natural LanguagesApr 02 1998Graph Interpolation Grammars are a declarative formalism with an operational semantics. Their goal is to emulate salient features of the human parser, and notably incrementality. The parsing process defined by GIGs incrementally builds a syntactic representation ... More
Quantum clock synchronization and quantum error correctionOct 29 2000I consider quantum protocols for clock synchronization, and investigate in particular whether entanglement distillation or quantum error-correcting codes can improve the robustness of these protocols. I also draw attention to some unanswered questions ... More
Fault-tolerant quantum computationDec 19 1997The discovery of quantum error correction has greatly improved the long-term prospects for quantum computing technology. Encoded quantum information can be protected from errors that arise due to uncontrolled interactions with the environment, or due ... More
Progress on Excited Hadrons in Lattice QCDDec 01 2011Dec 06 2011The study of excited hadron spectra using Lattice QCD is currently evolving. An important step toward obtaining resonance parameters from Lattice QCD is the calculation of finite volume energy spectra. Somewhat more rigorous studies of finite volume spectra ... More
Some new behaviour in the deformation theory of Kleinian groupsOct 16 2000We present examples of hyperbolizable 3-manifolds $M$ with the following property. Let $CC(\pi_1(M))$ denote the space of convex co-compact representations of $\pi_1(M)$. We show that for every $K\geq 1$ there exists a representation $\rho$ in $\bar {CC(\pi_1(M))}$ ... More
Quantum Quenches to a Critical Point in One Dimension: some further resultsJul 26 2015Jan 08 2016We describe several results concerning global quantum quenches from states with short-range correlations to quantum critical points whose low-energy properties are described by a 1+1-dimensional conformal field theory (CFT), extending the work of Calabrese ... More
Entanglement Entropy in Extended Quantum SystemsAug 22 2007After a brief introduction to the concept of entanglement in quantum systems, I apply these ideas to many-body systems and show that the von Neumann entropy is an effective way of characterising the entanglement between the degrees of freedom in different ... More
SLE(kappa,rho) and Conformal Field TheoryDec 10 2004Jan 13 2006SLE(kappa,rho) is a generalisation of Schramm-Loewner evolution which describes planar curves which are statistically self-similar but not conformally invariant in the strict sense. We show that, in the context of boundary conformal field theory, this ... More
Logarithmic Correlations in Quenched Random Magnets and PolymersNov 03 1999It is argued that logarithmic factors multiplying power law behavior are to be expected at or near non-mean field critical points of systems with short-range interactions described theoretically by any kind of n -> 0 limit, in which the effective free ... More
The Legacy of Ken WilsonAug 08 2013This is a brief account of the legacy of Ken Wilson in statistical physics, high energy physics, computing and education.
ADE and SLEOct 13 2006Nov 08 2006We point out that the probability law of a single domain wall separating clusters in ADE lattice models in a simply connected domain is identical to that of corresponding chordal curves in the lattice O(n) and Q-state Potts models, for suitable n or Q. ... More
Calogero-Sutherland model and bulk-boundary correlations in conformal field theoryOct 31 2003Jan 31 2004We show that, in any conformal field theory, the weights of all bulk primary fields that couple to N phi_{2,1} fields on the boundary are given by the spectrum of an N-particle Calogero-Sutherland model. The corresponding correlation function is simply ... More
Stochastic Loewner Evolution and Dyson's Circular EnsemblesJan 28 2003Nov 11 2003Stochastic Loewner Evolution (SLE_kappa) has been introduced as a description of the continuum limit of cluster boundaries in two-dimensional critical systems. We show that the problem of N radial SLEs in the unit disc is equivalent to Dyson's Brownian ... More
Renormalisation group approach to reaction-diffusion problemsJul 23 1996Sep 11 1996This is the text of a talk given at the conference in memory of Claude Itzykson at Saclay in June 1996. It contains an introductory survey and an account of recent developments in the field theoretic RG approach to reaction-diffusion problems.
Continuously Varying Exponents for Oriented Self-Avoiding WalksDec 07 1993A two-dimensional conformal field theory with a conserved $U(1)$ current $\vec J$, when perturbed by the operator ${\vec J}^{\,2}$, exhibits a line of fixed points along which the scaling dimensions of the operators with non-zero $U(1)$ charge vary continuously. ... More
An unavoidable set of D-reducible configurationsMay 01 2009May 04 2009We give a new proof of the four-color theorem by exhibiting an unavoidable set of 2822 D-reducible configurations. The existence of such a set had been conjectured by several researchers including Stromquist, Appel and Haken, and Robertson, Sanders, Seymour ... More
Millisecond Pulsar Searches and Double Neutron Star BinariesMay 04 2004May 06 2004A unified strategy is developed that can be used to search for millisecond pulsars (MSPs) with ~solar mass companions (including neutron star companions in double neutron star binaries [DNSBs]) belonging to both very short period binaries, and those with ... More
The SN 1987A Link to Others and Gamma-Ray BurstsAug 16 2007Feb 06 2008Early measurements of SN 1987A can be interpreted in light of a beam/jet (BJ), with a collimation factor >10,000, which impacted polar ejecta (PE) to produce the "Mystery Spot" (MS), ~24 lt-d away. Other details of SN 1987A suggest that it came from a ... More
Does merger-induced core-collapse produce gamma-ray bursts in type Ib & Ic supernovae?Oct 23 2003Nov 12 2003Gamma-ray bursts, discovered over three decades ago, can appear to be a hundred times as luminous as the brightest supernovae. However, there has been evidence for some time now of an association of gamma-ray bursts with supernovae of type Ib and Ic. ... More
What is superresolution microscopy?May 06 2014Oct 08 2014I explain what is, what is not, and what is only sort of superresolution microscopy. I discuss optical resolution, first in terms of diffraction theory, then in terms of linear systems theory, and finally in terms of techniques that use prior information, ... More
Generalized measurements by linear elementsAug 23 2001I give a first characterization of the class of generalized measurements that can be exactly realized on a pair of qudits encoded in indistinguishable particles, by using only linear elements and particle detectors. Two immediate results follow from this ... More
An Introduction To Solar Neutrino ResearchNov 18 1997The first lecture describes the conflicts between the combined standard model (minimal electroweak and solar) predictions and the results of solar neutrino experiments. The second lecture discusses the possibilities for detecting with solar neutrinos ... More
Structure, Individuality and Quantum GravityJul 18 2005Jul 19 2005After reviewing various interpretations of structural realism, I adopt here a definition that allows both relations between things that are already individuated (which I call ``relations between things'') and relations that individuate previously un-individuated ... More
Elliptical Galaxies and Bulges of Disk Galaxies: Summary of Progress and Outstanding IssuesApr 13 2015This is the summary chapter of a review book on galaxy bulges. Bulge properties and formation histories are more varied than those of ellipticals. I emphasize two advances: 1 - "Classical bulges" are observationally indistinguishable from ellipticals, ... More
Supermassive Black Holes in Disk GalaxiesJul 26 2000Dynamical searches find central dark objects - candidate supermassive black holes (BHs) - in at least 34 galaxies. The demographics of these objects lead to the following conclusions: (1) BH mass correlates with the luminosity of the bulge component of ... More
A Parallel Tree CodeMar 18 1996We describe a new implementation of a parallel N-body tree code. The code is load-balanced using the method of orthogonal recursive bisection to subdivide the N-body system into independent rectangular volumes each of which is mapped to a processor on ... More
Deleting Powers in WordsAug 30 2016We consider the language consisting of all words such that it is possible to obtain the empty word by iteratively deleting powers. It turns out that in the case of deleting squares in binary words this language is regular, and in the case of deleting ... More
ET Probes: Looking Here as Well as ThereAug 05 2016Almost all SETI searches to date have explicitly targeted stars in the hope of detecting artificial radio or optical transmissions. It is argued that extra-terrestrials (ET) might regard sending physical probes to our own Solar System as a more efficient ... More
Non-Markovian Quantum Feedback Networks I: Quantum Transmission Lines, Lossless Bounded Real Property and Limit Markovian ChannelsApr 08 2016The purpose of this paper is to set out the problems of modeling quantum communication and signal processing where the communication between systems via a non-Markovian channel. This is a general feature of quantum transmission lines. Our ultimate objective ... More
Feynman Diagrams and the Quantum Stochastic CalculusNov 09 2004We present quantum stochastic calculus in terms of diagrams taking weights in the algebra of observables of some quantum system. In particular, we note the absence of non-time-consecutive Goldstien diagrams. We review recent results in Markovian limits ... More
Boson-Fermion unification implemented by Wick calculusSep 10 2003Jan 15 2004We construct a transformation between Bose Fock space and Fermi Fock space that is super-symmetric in the sense that it converts Boson fields into Fermi fields over a fixed one-particle space. The transformation involves the spectral splitting of the ... More
Holevo-ordering and the continuous-time limit for open Floquet dynamicsNov 21 2003We consider an atomic beam reservoir as a source of quantum noise. The atoms are modelled as two-state systems and interact one-at-a-time with the system. The Floquet operators are described in terms of the Fermionic creation, annihilation and number ... More
Q-ball Evolution, B-ball Baryogenesis and the f_{B} ProblemDec 29 2000Feb 22 2001We consider some of the issues surrounding the formation and evolution of Q-balls in the MSSM and its extensions. The ratio of the baryon number packed into Q-balls to that outside, f_{B}, plays a fundamental role in determining the relationship of dark ... More
Signatures of Planck Corrections in a Spiralling Axion Inflation ModelDec 22 2014May 04 2015The minimal sub-Planckian axion inflation model accounts for a large scalar-to-tensor ratio via a spiralling trajectory in the field space of a complex field $\Phi$. Here we consider how the predictions of the model are modified by Planck scale-suppressed ... More
Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark MatterAug 23 2011Mar 05 2015The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the ... More
Unparticles: Interpretation and CosmologyMay 13 2008May 14 2008We discuss the physical interpretation of unparticles and review the constraints from cosmology. Unparticles may be understood in terms of confined states of a strongly-coupled scale-invariant theory, where scale-invariance implies that the confined states ... More
Positive Order H^2 Mass Corrections and Affleck-Dine BaryogenesisFeb 21 1999Mar 03 1999It is usually assumed that the order H^2 corrections to the SUSY-breaking mass squared terms in the early Universe must be negative in order to allow the Affleck-Dine mechanism to work. We reconsider this assumption in the context of D-term inflation ... More
Physics Beyond the Standard ModelJan 15 2000I briefly summarize the prospects for extending our understanding of physics beyond the standard model within the next five years.
Bayes versus the virial theorem: inferring the potential of a galaxy from a kinematical snapshotMar 25 2013Oct 21 2013We present a new framework for estimating a galaxy's gravitational potential, Phi(x), from its stellar kinematics by adopting a fully non-parametric model for the galaxy's unknown action-space distribution function, f(J). Having an expression for the ... More
Category $\mathcal{J}$ Modules for Hamiltonian Vector Fields on a TorusOct 29 2016Modules for the Lie algebra of Hamiltonian vector fields on a torus, which admit a compatible action for the commutative algebra of multivariate Laurent polynomials are called category $\mathcal{J}$. This paper classifies the indecomposable and the irreducible ... More
Study of the Decays KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e- at KTeVMar 15 1999We present new results on the related rare KL decay modes KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e-. KTeV has performed the first direct measurement of the form factor for the "direct emission" component of KL -> pi+ pi- gamma decays, a quantity with ... More
Specht modules and semisimplicity criteria for Brauer and Birman--Murakami--Wenzl AlgebrasMay 29 2007A construction of bases for cell modules of the Birman--Murakami--Wenzl (or B--M--W) algebra $B_n(q,r)$ by lifting bases for cell modules of $B_{n-1}(q,r)$ is given. By iterating this procedure, we produce cellular bases for B--M--W algebras on which ... More
Generalized Gaugino Condensation in Super Yang-Mills Theories: Discrete R-Symmetries and VacuaMay 25 2010One can define generalized models of gaugino condensation as theories which dynamically break a discrete R-symmetry, but do not break supersymmetry. We consider general examples consisting of gauge and matter fields, and the minimal number of gauge singlet ... More
`t Hooft Anomaly Matching for QCDJun 10 1997Mar 03 1998I present a set of theories which display non-trivial `t Hooft anomaly matching for QCD with $F$ flavors. The matching theories are non-Abelian gauge theories with "dual" quarks and baryons, rather than the purely confining theories of baryons that `t ... More
Naturally Light ScalarsOct 04 1995I argue that in certain chiral gauge theories composite scalars associated with chiral symmetry breaking can be light (i.e. lighter than naive scaling from QCD would suggest) without any fine-tuning. These scalars will be even lighter in chiral gauge ... More
The Multichannel Quark ModelJun 19 1996We discuss the non-relativistic multichannel quark model and describe the techniques developed to solve the resulting equations. We then investigate some simple solutions to demonstrate how the model unifies meson-meson scattering with meson spectroscopy, ... More
Fields of Rationality of Cusp FormsFeb 03 2015Dec 09 2015In this paper, we prove that for any totally real field $F$, weight $k$, and nebentypus character $\chi$, the proportion of Hilbert cusp forms over $F$ of weight $k$ and character $\chi$ with bounded field of rationality approaches zero as the level grows ... More
Limit on an Isotropic Diffuse Gamma-Ray Population with HAWCAug 17 2015Data from 105 days from the High Altitude Water Cherenkov Observatory (HAWC) have been used to place a new limit on an isotropic diffuse gamma-ray population above 10 TeV. High- energy isotropic diffuse gamma-ray emission is produced by unresolved extragalactic ... More
Ising Model Scaling Functions at Short DistanceJul 06 2001A method for proving the Luther-Peschel formula for the short distance asymptotics of the Ising model scaling functions is sketched.
Deformation analysis of matrix modelsMar 03 1994The Tracy-Widom equations associated with level spacing distributions are realized as a special case of monodromy preserving deformations.