Results for "Christopher Groppi"

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Warm-Dense Molecular Gas in the ISM of Starbursts, LIRGs and ULIRGsApr 19 2005The role of star formation in luminous and ultraluminous infrared galaxies is a hotly debated issue: while it is clear that starbursts play a large role in powering the IR luminosity in these galaxies, the relative importance of possible enshrouded AGNs ... More
Vibrationally Excited HCN around AFGL 2591: A Probe of Protostellar StructureFeb 08 2013Vibrationally excited molecules with sub-mm rotational transitions are potentially excellent probes of physical conditions near protostars. This study uses observations of the v=1 and v=2 ro-vibrational modes of HCN (4-3) to probe this environment. The ... More
Millimeter and Submillimeter Survey of the R Corona Australis RegionMay 03 2004Jun 08 2004Using a combination of data from the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), the Arizona Radio Observatory Kitt Peak 12m telescope and the Arizona Radio Observatory 10m Heinrich Hertz Telescope, we have studied the most active ... More
A Compact Filter-Bank Waveguide Spectrometer for Millimeter WavelengthsFeb 09 2015May 13 2015We present the design and measurements of a 90GHz prototype of a millimeter-wave channelizing spectrometer realized in rectangular waveguide for astronomical instrumentation. The device was fabricated using conventional high-precision metal machining, ... More
High Spatial Resolution Observations of Two Young Protostars in the R Corona Australis RegionJul 19 2007We present multi-wavelength, high spatial resolution imaging of the IRS 7 region in the R Corona Australis molecular cloud. Our observations include 1.1 mm continuum and HCO^+ J = $3 \to 2$ images from the SMA, ^{12}CO J = $3 \to 2$ outflow maps from ... More
Star Formation in the Northern Cloud Complex of NGC 2264Mar 09 2006We have made continuum and spectral line observations of several outflow sources in the Mon OB1 dark cloud (NGC 2264) using the Heinrich Hertz Telescope (HHT) and ARO 12m millimeter-wave telescope. This study explores the kinematics and outflow energetics ... More
First Generation Heterodyne Instrumentation Concepts for the Atacama Large Aperture Submillimeter TelescopeJul 08 2019(abridged) The Atacama Large Aperture Submillimeter Telescope (AtLAST) project aims to build a 50-m-class submm telescope with $>1^\circ$ field of view, high in the Atacama Desert, providing fast and detailed mapping of the mm/submm sky. It will thus ... More
WSPEC: A Waveguide Filter Bank SpectrometerMar 23 2015We have designed, fabricated, and measured a 5-channel prototype spectrometer pixel operating in the WR10 band to demonstrate a novel moderate-resolution (R=f/{\Delta}f~100), multi-pixel, broadband, spectrometer concept for mm and submm-wave astronomy. ... More
Testing the AGN-Starburst Connection in Seyfert GalaxiesJul 13 2000Jul 17 2000We use the CO band at 2.3 micron to constrain the populations of young stars in the central regions of Seyfert galaxies. We report new CO band spectroscopy of 46 Seyfert galaxies. In most cases, the observed CO indices appear diluted by the presence of ... More
Measuring Water Vapor and Ash in Volcanic Eruptions with a Millimeter-Wave Radar/ImagerApr 13 2016Millimeter-wave remote sensing technology can significantly improve measurements of volcanic eruptions, yielding new insights into eruption processes and improving forecasts of drifting volcanic ash for aviation safety. Radiometers can measure water vapor ... More
Analysis techniques for complex-field radiation pattern measurementsSep 21 2018Complex field measurements are increasingly becoming the standard for state-of-the-art astronomical instrumentation. Complex field measurements have been used to characterize a suite of ground, airborne, and space-based heterodyne receiver missions [1], ... More
Measuring Water Vapor and Ash in Volcanic Eruptions with a Millimeter-Wave Radar/ImagerApr 13 2016Feb 01 2017Millimeter-wave remote sensing technology can significantly improve measurements of volcanic eruptions, yielding new insights into eruption processes and improving forecasts of drifting volcanic ash for aviation safety. Radiometers can measure water vapor ... More
Tidal Tails of Minor Mergers II: Comparing Star Formation in the Tidal Tails of NGC 2782Jul 30 2013The peculiar spiral NGC 2782 is the result of a minor merger with a mass ratio ~4:1 occurring ~200 Myr ago. This merger produced a molecular and HI rich, optically bright Eastern tail and an HI-rich, optically faint Western tail. Non-detection of CO in ... More
A Superconducting Phase Shifter and Traveling Wave Kinetic Inductance Parametric Amplifier for W-Band AstronomyOct 31 2017The W-Band ($75-110\; \mathrm{GHz}$) sky contains a plethora of information about star formation, galaxy evolution and the cosmic microwave background. We have designed and fabricated a dual-purpose superconducting circuit to facilitate the next generation ... More
WSPEC: A waveguide filter-bank focal plane array spectrometer for millimeter wave astronomy and cosmologySep 15 2015Imaging and spectroscopy at (sub-)millimeter wavelengths are key frontiers in astronomy and cosmology. Large area spectral surveys with moderate spectral resolution (R=50-200) will be used to characterize large scale structure and star formation through ... More
SuperCam, a 64-pixel heterodyne imaging array for the 870 micron atmospheric windowJun 02 2006We report on the development of SuperCam, a 64 pixel, superheterodyne camera designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of ... More
Unimodal probability distributions for deep ordinal classificationMay 15 2017Jun 22 2017Probability distributions produced by the cross-entropy loss for ordinal classification problems can possess undesired properties. We propose a straightforward technique to constrain discrete ordinal probability distributions to be unimodal via the use ... More
A simple squared-error reformulation for ordinal classificationDec 02 2016In this paper, we explore ordinal classification (in the context of deep neural networks) through a simple modification of the squared error loss which not only allows it to not only be sensitive to class ordering, but also allows the possibility of having ... More
A step towards procedural terrain generation with GANsJul 11 2017Procedural terrain generation for video games has been traditionally been done with smartly designed but handcrafted algorithms that generate heightmaps. We propose a first step toward the learning and synthesis of these using recent advances in deep ... More
A simple squared-error reformulation for ordinal classificationDec 02 2016Jan 09 2017In this paper, we explore ordinal classification (in the context of deep neural networks) through a simple modification of the squared error loss which not only allows it to not only be sensitive to class ordering, but also allows the possibility of having ... More
The Atacama Large Aperture Submillimeter Telescope (AtLAST)Jul 10 2019The sub-mm sky is a unique window for probing the architecture of the Universe and structures within it. From the discovery of dusty sub-mm galaxies, to the ringed nature of protostellar disks, our understanding of the formation, destruction, and evolution ... More
High order semi-Lagrangian methods for the BGK equationNov 28 2014A new class of high-order accuracy numerical methods for the BGK model of the Boltzmann equation is presented. The schemes are based on a semi-lagrangian formulation of the BGK equation; time integration is dealt with DIRK (Diagonally Implicit Runge Kutta) ... More
High posterior density ellipsoids of quantum statesOct 07 2013Regions of quantum states generalize the classical notion of error bars. High posterior density (HPD) credible regions are the most powerful of region estimators. However, they are intractably hard to construct in general. This paper reports on a numerical ... More
Supersymmetric AdS$_{5}$ solutions of type IIB supergravity without D3 branesSep 16 2016We analyse the most general bosonic supersymmetric solutions of type IIB supergravity whose metrics are warped products of five-dimensional anti-de Sitter space (AdS$_5$) with a five-dimensional Riemannian manifold $M_{5}$, where the five-form flux vanishes, ... More
Normal subgroup growth in free class-2-nilpotent groupsSep 21 2004Let $F_{2,d}$ denote the free class-2-nilpotent group on $d$ generators. We compute the normal zeta functions $\zeta^\triangleleft_{F_{2,d}}(s)$, prove that they satisfy local functional equations and determine their abscissae of convergence and pole ... More
Flavor Violation as a Probe of the MSSM Higgs SectorMar 28 2000At moderate to large tan(beta), it is no longer possible to simultaneously diagonalize the masses of quarks and their couplings to the neutral Higgs bosons. The resulting flavor violations of the form (\bar b_R d_L H) and (\bar b_R s_L H) do not generate ... More
Midi-Superspace Quantization of Non-Compact Toroidally Symmetric GravityJan 29 1998We consider the quantization of the midi-superspace associated with a class of spacetimes with toroidal isometries, but without the compact spatial hypersurfaces of the well-known Gowdy models. By a symmetry reduction, the phase space for the system at ... More
Broken Isotropy from a Linear Modulation of the Primordial PerturbationsJul 18 2006Oct 30 2006A linear modulation of the primordial perturbations is proposed as an explanation for the observed asymmetry between the northern and southern hemispheres of the Wilkinson Microwave Anisotropy Probe (WMAP) data. A cut sky, reduced resolution third year ... More
Automated lattice perturbation theoryOct 16 2013Oct 22 2013I review recent developments in automated lattice perturbation theory. Starting with an overview of lattice perturbation theory, I focus on the three automation packages currently "on the market": HiPPy/HPsrc, Pastor and PhySyCAl. I highlight some recent ... More
The Beauty of Lattice Perturbation Theory: The Role of Lattice Perturbation Theory in B PhysicsOct 26 2012Jul 10 2013As new experimental data arrive from the LHC the prospect of indirectly detecting new physics through precision tests of the Standard Model grows more exciting. Precise experimental and theoretical inputs are required to test the unitarity of the CKM ... More
A Search For the Higgs Boson in CMS in the Two Photon Decay ChannelSep 30 2011We report on a search for SM Higgs Boson in the two photon decay mode conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at center of mass collision energy of 7 TeV.
Experimental Studies of Artificial Spin IceNov 02 2016Artificial spin ices were originally introduced as analogs of the pyrochlore spin ices, but have since become a much richer field . The original attraction of building nanotechnological analogs of the pyrochlores were threefold: to allow room temperature ... More
Spectator Effects in Heavy Quark Effective Theory at O(1/m_Q^3)May 29 1998We complete the one loop renormalization of the HQET lagrangian at O(1/m_Q^3) including four fermion operators with two heavy and two light quark fields in the operator basis. It is shown that as a consequence the short distance coefficients of the operators ... More
Hydrodynamics of spacetime and vacuum viscosityJun 19 2008Nov 14 2008It has recently been shown that the Einstein equation can be derived by demanding a non-equilibrium entropy balance law dS = dQ/T + dS_i hold for all local acceleration horizons through each point in spacetime. The entropy change dS is proportional to ... More
Subshifts of finite type which have completely positive entropyJan 02 2012Domino tilings have been studied extensively for both their statistical properties and their dynamical properties. We construct a subshift of finite type using matching rules for several types of dominos. We combine the previous results about domino tilings ... More
Search for the Lepton Number Violating Decay Tau to Mu GammaDec 04 2002Using data collected with the BaBar detector between 1999 and 2001, we describe a preliminary search for the neutrinoless decay Tau to Mu Gamma. This data sample includes data collected both on and off the Upsilon(4S) resonance and corresponds to 56 million ... More
Fundamental groups and good reduction criteria for curves over positive characteristic local fieldsApr 20 2016In this article I define and study the overconvergent rigid fundamental group of a variety over an equicharacteristic local field. This is a non-abelian $(\varphi,\nabla)$-module over the bounded Robba ring $\mathcal{E}_K^\dagger$, whose underlying unipotent ... More
Relative Fundamental Groups and Rational PointsMar 26 2013Oct 23 2014In this paper we define a relative rigid fundamental group, which associates to a section $p$ of a smooth and proper morphism $f:X\rightarrow S$ in characteristic $p$, a Hopf algebra in the ind-category of overconvergent $F$-isocrystals on $S$. We prove ... More
A geometric proof of Lück's vanishing theorem for the first $L^2$-Betti number of the total space of a fibrationNov 24 2016A significant theorem of L\"uck says that the first $L^2$-Betti number of the total space of a fibration vanishes under some conditions on the fundamental groups. The proof is based on constructions on chain complexes. In the present paper, we translate ... More
Spontaneously Broken Asymptotic Symmetries and an Effective Action for Horizon DynamicsNov 30 2016Asymptotic spacetime symmetries have been conjectured to play an important role in quantum gravity. In this paper we study the breaking of asymptotic symmetries associated with a null horizon boundary. In two-dimensions, these symmetries are reparametrizations ... More
Anisotropic Coherence properties in a trapped quasi2D dipolar gasSep 10 2012Oct 02 2012We consider a trapped quasi2D dipolar Bose Einstein condensate (q2D DBEC) with a polariza- tion tilted into the plane of motion. We show that by tilting the polarization axis, the coherence properties are anisotropic. Such a system will have density fluctuations ... More
Two dimensional dipolar scattering with a tiltApr 21 2011We study two body dipolar scattering in two dimensions with a tilted polarization axis. This tilt reintroduces the anisotropic interaction in a controllable manner. As a function of this polarization angle we present the scattering results in both the ... More
Quasi-two dimensional dipolar scatteringMar 18 2010We study two body dipolar scattering with one dimension of confinement. We include the effects of confinement by expanding this degree of freedom in harmonic oscillator states. We then study the properties of the resulting multi-channel system. We study ... More
Double Helicity Asymmetries of Forward Neutral Pions from $\sqrt{s}=510$ GeV $pp$ Collisions at STARMay 22 2018Longitudinally polarized $p+p$ scattering experiments provide access to gluon polarization via measurement of the double helicity asymmetry, $A_{LL}$. At the completion of the 2013 RHIC running period, a significant dataset of $\pi^{0}$s corresponding ... More
Dynamical systems for arithmetic schemesJul 17 2018Feb 21 2019In the present paper we construct infinite-dimensional continuous-time dynamical systems attached to integral normal schemes which are flat and of finite type over the spectrum of the integers. We study the periodic orbits and connectedness properties ... More
Eight circles through the OrthocentreAug 12 2010A construction is given of five Hagge circles complete with supporting calculations.
Resolving Irreducible $\mathbb{C}S_n$-Modules by Modules Restricted from $GL_n(\mathbb{C})$Dec 18 2018We construct a resolution of irreducible complex representations of the symmetric group $S_n$ by restrictions of representations of $GL_n(\mathbb{C})$ (where $S_n$ is the subgroup of permutation matrices). This categorifies a recent result of Assaf and ... More
Multi-level Approximate Bayesian ComputationNov 21 2018Approximate Bayesian Computation is widely used to infer the parameters of discrete-state continuous-time Markov networks. In this work, we focus on models that are governed by the Chemical Master Equation (the CME). Whilst originally designed to model ... More
Impulsive Electromagnetic Emission near a Black HoleOct 30 2018Apr 08 2019The electromagnetic signature of a point explosion near a Kerr black hole (BH) is evaluated. The first repetitions produced by gravitational lensing are not periodic in time; periodicity emerges only as the result of multiple circuits of the prograde ... More
Combining non-stationary prediction, optimization and mixing for data compressionFeb 12 2013In this paper an approach to modelling nonstationary binary sequences, i.e., predicting the probability of upcoming symbols, is presented. After studying the prediction model we evaluate its performance in two non-artificial test cases. First the model ... More
Rare K decays: Challenges and PerspectivesSep 22 2014At this stage of the LHC program, the prospect for a new physics signal in the very rare K ---> pi nu nu bar decays may be dented, but remains well alive thanks to their intrinsic qualities. First, these decays are among the cleanest observables in the ... More
Theoretical perspective on the NA62 physics programDec 16 2010Soon the NA62 experiment will start looking for the rare K+ ---> pi+ nu nu bar decay. In this talk, its theoretical interests, together with those of the neutral rare decays KL ---> pi0 nu nu bar, KL ---> pi0 e+ e-, and KL ---> pi0 mu+ mu-, are briefly ... More
Long-Distance Effects in Rare K DecaysMay 18 2005Rare K decays provide for very clean tests of the Standard Model, and are especially suited to search for New Physics signal. In this talk, recent progresses in the estimation of long-distance effects induced by light quarks in KL to pi0 mu+ mu- and K+ ... More
Very low energy matching of effective meson theories with QCDJul 23 2002A simple matching procedure is proposed to extract constraints on effective meson theories. In this way, a QCD prediction for the pion decay constant is found, F(pi)=2 m(pi)/pi, i.e. approximately 90MeV. The same procedure also determines other mesonic ... More
Knot contact homology and representations of knot groupsMar 20 2013Aug 27 2014We study certain linear representations of the knot group that induce augmentations of knot contact homology. This perspective on augmentations enhances our understanding of the relationship between the augmentation polynomial and the A-polynomial of ... More
On enumerating extensions of p-adic fields with given invariantsMar 21 2018We give a brief re-exposition of the theory due to Pauli and Sinclair of ramification polygons of Eisenstein polynomials over p-adic fields, their associated residual polynomials and an algorithm to produce all extensions for a given ramification polygon. ... More
Training on test data: Removing near duplicates in Fashion-MNISTJun 19 2019MNIST and Fashion MNIST are extremely popular for testing in the machine learning space. Fashion MNIST improves on MNIST by introducing a harder problem, increasing the diversity of testing sets, and more accurately representing a modern computer vision ... More
A note on effective descent for overconvergent isocrystalsJun 16 2017Jul 11 2017In this short note we explain the proof that proper surjective and faithfully flat maps are morphisms of effective descent for overconvergent isocrystals. We then show how to deduce the folklore theorem that for an arbitrary variety over a perfect field ... More
Incarnations of Berthelot's conjectureAug 27 2015Jan 18 2017In this article we give a survey of the various forms of Berthelot's conjecture and some of the implications between them. By proving some comparison results between pushforwards of overconvergent isocrystals and those of arithmetic $\mathcal{D}$-modules, ... More
Fundamental groups and good reduction criteria for curves over positive characteristic local fieldsApr 20 2016Jun 13 2017In this article I define and study the overconvergent rigid fundamental group of a variety over an equicharacteristic local field. This is a non-abelian $(\varphi,\nabla)$-module over the bounded Robba ring $\mathcal{E}_K^\dagger$, whose underlying unipotent ... More
Zeta functions of groups - singular PfaffiansSep 30 2003The local normal zeta functions of a finitely generated, torsion-free nilpotent group $G$ of class 2 depend on the geometry of the Pfaffian hypersurface associated to the bilinear form induced by taking commutators in $G$. The smallest examples of zeta ... More
KCH representations, augmentations, and $A$-polynomialsOct 28 2013Jun 05 2017We describe a correspondence between augmentations and certain representations of the knot group. The correspondence makes the 2-variable augmentation polynomial into a generalization of the classical $A$-polynomial. It also associates to an augmentation ... More
Coarse indices of twisted operatorsJun 03 2016Jan 01 2018Several formulas for computing coarse indices of twisted Dirac type operators are introduced. One type of such formulas is by composition product in $E$-theory. The other type is by module multiplications in $K$-theory, which also yields an index theoretic ... More
All CAT(0) Boundaries of a Group of the Form HxK are CE EquivalentJul 29 2007M. Bestvina has shown that for any given torsion-free CAT(0) group G, all of its boundaries are shape equivalent. He then posed the question of whether they satisfy the stronger condition of being cell-like equivalent. In this article we prove that the ... More
Examples of Non-Rigid CAT(0) Groups from the Category of Knot GroupsJun 11 2007Aug 06 2008C Croke and B Kleiner have constructed an example of a CAT(0) group with more than one visual boundary. J Wilson has proven that this same group has uncountably many distinct boundaries. In this article we prove that the knot group of any connected sum ... More
Quantum Chess: Developing a Mathematical Framework and Design Methodology for Creating Quantum GamesJun 13 2019Quantum phenomena have remained largely inaccessible to the general public. This can be attributed to the fact that we do not experience quantum mechanics on a tangible level in our daily lives. Games can provide an environment in which people can experience ... More
A Complete Obstruction to the Existence of Nonvanishing Vector Fields on Almost-Complex, Closed, Cyclic OrbifoldsAug 14 2004Aug 03 2006We determine several necessary and sufficient conditions for a closed almost-complex orbifold $Q$ with cyclic local groups to admit a nonvanishing vector field. These conditions are stated separately in terms of the orbifold Euler-Satake characteristics ... More
Multiplicative reduction and the cyclotomic main conjecture for $\mathrm{GL}_2$Jul 04 2014We show that the cyclotomic Iwasawa--Greenberg Main Conjecture holds for a large class of modular forms with multiplicative reduction at $p$, extending previous results for the good ordinary case. In fact, the multiplicative case is deduced from the good ... More
p-adic limits of renormalized logarithmic Euler characteristicsJan 08 2018Given a countable residually finite group $\Gamma$, we write $\Gamma_n \to e$ if $(\Gamma_n)$ is a sequence of normal subgroups of finite index such that any infinite intersection of $\Gamma_n$'s contains only the unit element $e$ of $\Gamma$. Given a ... More
Newton-Okounkov polyhedra for character varieties and configuration spacesMar 17 2014Jul 13 2016We construct families of Newton-Okounkov bodies for the free group character varieties and configuration spaces of any connected reductive group. We use this construction to give a proof that these spaces are Cohen-Macaulay.
Toric Degenerations and tropical geometry of branching algebrasMar 12 2011Aug 27 2012We construct polyhedral families of valuations on the branching algebra of a morphism of reductive groups. This establishes a connection between the combinatorial rules for studying a branching problem and the tropical geometry of the branching algebra. ... More
Faithfulness of bi-free product statesMar 16 2017Apr 17 2018Given a non-trivial family of pairs of faces of unital C*-algebras where each pair has a faithful state, it is proved that if the bi-free product state is faithful on the reduced bi-free product of this family of pairs of faces then each pair of faces ... More
Local functional equations for submodule zeta functions associated to nilpotent algebras of endomorphismsFeb 23 2016Jul 23 2017We give a sufficient criterion for generic local functional equations for submodule zeta functions associated to nilpotent algebras of endomorphisms defined over number fields. This allows us, in particular, to prove various conjectures on such functional ... More
Counting the spanning trees of the 3-cube using edge slidesSep 29 2011Oct 02 2012We give a direct combinatorial proof of the known fact that the 3-cube has 384 spanning trees, using an "edge slide" operation on spanning trees. This gives an answer in the case n=3 to a question implicitly raised by Stanley. Our argument also gives ... More
Propagation of solutions to the Fisher-KPP equation with slowly decaying initial dataMay 29 2015The Fisher-KPP equation is a model for population dynamics that has generated a huge amount of interest since its introduction in 1937. The speed with which a population spreads has been computed quite precisely when the initial data decays exponentially. ... More
Cox rings of moduli of quasi parabolic principal bundles and the K-Pieri ruleSep 22 2013Jun 13 2016We study a toric degeneration of the Cox ring of the moduli of principal $SL_m(\mathbb{C})$ bundles on the projective line, with quasi parabolic data given by the the stabilizer of the highest weight vector in $\mathbb{C}^m$ and its dual $\bigwedge^{m-1}(\mathbb{C}^m)$. ... More
Counting rational points over number fields on a singular cubic surfaceApr 02 2012Nov 04 2013A conjecture of Manin predicts the distribution of K-rational points on certain algebraic varieties defined over a number field K. In recent years, a method using universal torsors has been successfully applied to several hard special cases of Manin's ... More
A rank inequality for the Tate Conjecture over global function fieldsNov 30 2008Aug 08 2015Following D. Ramakrishnan, we explain how L. Lafforgue's modularity theorem and an analytic theorem of H. Jacquet and J. Shalika can be applied to prove the following result related to the Tate Conjecture: for a smooth, projective, geometrically-connected ... More
Finite subset spaces of S^1Sep 07 2002Dec 17 2002Given a topological space X denote by exp_k(X) the space of non-empty subsets of X of size at most k, topologised as a quotient of X^k. This space may be regarded as a union over 0 < l < k+1 of configuration spaces of l distinct unordered points in X. ... More
Finite subset spaces of closed surfacesNov 21 2003The kth finite subset space of a topological space X is the space exp_k X of non-empty finite subsets of X of size at most k, topologised as a quotient of X^k. The construction is a homotopy functor and may be regarded as a union of configuration spaces ... More
Finite subset spaces of graphs and punctured surfacesOct 21 2002Oct 05 2003The kth finite subset space of a topological space X is the space exp_k X of non-empty finite subsets of X of size at most k, topologised as a quotient of X^k. The construction is a homotopy functor and may be regarded as a union of configuration spaces ... More
A dynamical systems analogue of Lichtenbaum's conjectures on special values of Hasse-Weil zeta functionsMay 29 2006May 31 2007In recent years Lichtenbaum has conjectured a description for the special values of Hasse--Weil zeta functions in terms of ``Weil-\'etale cohomology''. In earlier papers we studied a class of foliated dynamical systems which had some similarities with ... More
The gradient flow in simple field theoriesDec 01 2015The gradient flow is a valuable tool for the lattice community, with applications from scale-setting to implementing chiral fermions. Here I focus on the gradient flow as a means to suppress power-divergent mixing. Power-divergent mixing stems from the ... More
The p-Cycle of Holonomic D-modules and Automorphisms of the Weyl AlgebraOct 20 2015We construct a correspondence between smooth algebraic Lagrangians in the cotangent bundle of complex affine n-space which satisfy some (co)homology vanishing assumptions and a certain class of holonomic modules over the n-th Weyl algebra. The association ... More
Traces on Topological Graph AlgebrasMay 11 2016Given a topological graph $E$, we give a complete description of tracial states on the C*-algebra $\mathrm{C}^*(E)$ which are invariant under the gauge action; there is an affine homeomorphism between the space of gauge invariant tracial states on $\mathrm{C}^*(E)$ ... More
A Characterization of Prediction ErrorsNov 18 2016Understanding prediction errors and determining how to fix them is critical to building effective predictive systems. In this paper, we delineate four types of prediction errors and demonstrate that these four types characterize all prediction errors. ... More
Supersymmetric AdS$_{5}$ solutions of type IIB supergravity without D3 branesSep 16 2016Nov 07 2016We analyse the most general bosonic supersymmetric solutions of type IIB supergravity whose metrics are warped products of five-dimensional anti-de Sitter space (AdS$_5$) with a five-dimensional Riemannian manifold $M_{5}$, where the five-form flux vanishes, ... More
Rigid rational homotopy typesJun 27 2013Apr 23 2014In this paper we define a rigid rational homotopy type, associated to any variety $X$ over a perfect field $k$ of positive characteristic. We prove comparison theorems with previous definitions in the smooth and proper, and log-smooth and proper case. ... More
Dispersion relation and excitation character of a two-component Bose-Einstein condensateMar 12 2014We present a study for the dispersion relation and character of the excitations of a single and two component Bose Einstein Condensate (BEC). We study the single component dispersion for a finite BEC system and look at examples of quasiparticles to understand ... More
Excitations of a trapped two component Bose Einstein CondensateApr 25 2013Jul 15 2013We present analysis of the excitation spectrum for a 2 component quasi2D Bose Einstein Condensate. We study how the character of the excitations change across the miscible to immiscible phase transition. We find that the bulk excitations are typical of ... More
XENON10/100 dark matter constraints: examining the Leff dependenceDec 17 2010The determination of dark matter constraints from liquid xenon direct detection experiments depends upon the amount of scintillation light produced by nuclear recoils in the detector, a quantity that is characterized by the scintillation efficiency factor ... More
Involutive A-infinity algebras and dihedral cohomologySep 06 2012Sep 12 2013We define and study the cohomology theories associated to A-infinity algebras and cyclic A-infinity algebras equipped with an involution, generalising dihedral cohomology to the A-infinity context. Such algebras arise, for example, as unoriented versions ... More
Equivariant Coherent Sheaves, Soergel Bimodules, and Categorification of Affine Hecke AlgebrasAug 19 2011We give a description of certain categories of equivariant coherent sheaves on Grothendieck's resolution in terms of the categorical affine Hecke algebra of Soergel. As an application, we deduce a relationship of these coherent sheaf categories to the ... More
Geometric characterizations of asymptotic flatness and linear momentum in general relativitySep 21 2014Aug 05 2015In 1996, Huisken-Yau proved that every three-dimensional Riemannian manifold can be uniquely foliated near infinity by stable closed surfaces of constant mean curvature (CMC) if it is asymptotically equal to the (spatial) Schwarzschild solution. Later, ... More
Resurgent Supersymmetry and String TheoryAug 20 2014Jul 16 2015We study a realization of accidental supersymmetry in type IIB string theory as a proof-of-principle of the mechanism and as a prototype of the strong sector present in resurgent supersymmetry, a warped UV-completion of natural supersymmetry. We first ... More
Key recycling in authenticationFeb 06 2012Sep 29 2014In their seminal work on authentication, Wegman and Carter propose that to authenticate multiple messages, it is sufficient to reuse the same hash function as long as each tag is encrypted with a one-time pad. They argue that because the one-time pad ... More
Incarnations of Berthelot's conjectureAug 27 2015In this article we give a survey of the various forms of Berthelot's conjecture and some of the implications between them. By proving some comparison results between pushforwards of overconvergent isocrystals and those of arithmetic $\mathcal{D}$-modules, ... More
Essential Cohomology of the p-Groups with a Cyclic Subgroup of Index pJun 24 2010Jun 25 2010In this paper we determine explicitly the mod-p essential cohomology ideals of the p-groups with a cyclic subgroup of index p.
Gauge-Mediated Supersymmetry Breaking: Introduction, Review and UpdateJul 24 1997Recent progress in the gauge-mediated supersymmetry breaking is reviewed, with emphasis on the theoretical problems which gauge-mediated models so successfully solve, as well as those problems which are endemic to the models themselves and still beguile ... More
Approximate Killing Fields as an Eigenvalue ProblemAug 12 2008Approximate Killing vector fields are expected to help define physically meaningful spins for non-symmetric black holes in general relativity. However, it is not obvious how such fields should be defined geometrically. This paper relates a definition ... More