Results for "D. Cox"

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Layered posets and Kunen's universal collapseMay 30 2015Jul 16 2016We develop the theory of layered posets, and use the notion of layering to prove a new iteration theorem (Theorem 6): if $\kappa$ is weakly compact then any universal Kunen iteration of $\kappa$-cc posets (each possibly of size $\kappa$) is $\kappa$-cc, ... More
Chang's Conjecture and semiproperness of nonreasonable posetsMay 01 2016Let $\mathbb{Q}$ denote the poset which adds a Cohen real then shoots a club through the complement of $\big( [\omega_2]^\omega \big)^V$ with countable conditions. We prove that the version of Strong Chang's Conjecture from \cite{MR2965421} implies semiproperness ... More
Chang's Conjecture and semiproperness of nonreasonable posetsMay 01 2016Feb 16 2018Let $\mathbb{Q}$ denote the poset which adds a Cohen real then shoots a club through the complement of $\big( [\omega_2]^\omega \big)^V$ with countable conditions. We prove that the version of Strong Chang's Conjecture from \cite{MR2965421} implies semiproperness ... More
Calculations of the Knight Shift Anomalies in Heavy Electron MaterialsJun 11 1997Jun 12 1997We have studied the Knight shift $K(\vec r, T)$ and magnetic susceptibility $\chi(T)$ of heavy electron materials, modeled by the infinite U Anderson model with the NCA method. A systematic study of $K(\vec r, T)$ and $\chi(T)$ for different Kondo temperatures ... More
Optimal Domination PolynomialsApr 12 2019Let $G$ be a graph on $n$ vertices and $m$ edges and $D(G,x)$ the domination polynomial of $G$. In this paper we completely characterize the values of $n$ and $m$ for which optimal graphs exist for domination polynomials. We also show that there does ... More
Frequentist statistics as a theory of inductive inferenceOct 27 2006After some general remarks about the interrelation between philosophical and statistical thinking, the discussion centres largely on significance tests. These are defined as the calculation of $p$-values rather than as formal procedures for ``acceptance'' ... More
Smoothing and mean-covariance estimation of functional data with a Bayesian hierarchical modelFeb 24 2014Jul 07 2015Functional data, with basic observational units being functions (e.g., curves, surfaces) varying over a continuum, are frequently encountered in various applications. While many statistical tools have been developed for functional data analysis, the issue ... More
Ideal wet two-dimensional foams and emulsions with finite contact angleApr 27 2018We present simulations that show that an ideal two-dimensional foam with a finite contact angle develops an inhomogeneity for high liquid fraction $\phi$. In liquid-liquid emulsions this inhomogeneity is known as flocculation. In the case of an ordered ... More
Benchmarking the performance of Density Functional Theory and Point Charge Force Fields in their Description of sI Methane Hydrate against Diffusion Monte CarloFeb 27 2014May 12 2014High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation ... More
Correlated hybridization in transition metal complexesSep 09 2005May 17 2006We apply local orbital basis density functional theory (using SIESTA) coupled with a mapping to the Anderson impurity model to estimate the Coulomb assisted or correlated hybridization between transition metal d-orbitals and ligand sp-orbitals for a number ... More
On the Universal Central Extension of Hyperelliptic Current AlgebrasMar 11 2015Jul 20 2015Let $p(t)\in\mathbb C[t]$ be a polynomial with distinct roots and nonzero constant term. We describe, using Fa\'a de Bruno's formula and Bell polynomials, the universal central extension in terms of generators and relations for the hyperelliptic current ... More
Extending Chacon-Walsh: minimality and generalised starting distributionsMar 24 2005In this paper we consider the Skorokhod embedding problem for general starting and target measures. In particular, we provide necessary and sufficient conditions for a stopping time to be minimal in the sense of Monroe(1972). The resulting conditions ... More
On the universality of the nonstationary idealApr 19 2017Sep 19 2017Burke \cite{MR1472122} proved that the generalized nonstationary ideal, denoted NS, is universal in the following sense: every normal ideal, and every tower of normal ideals of inaccessible height, is a canonical Rudin-Keisler projection of the restriction ... More
Resistivity of the Two-Channel Kondo Model in Infinite DimensionsMay 17 1994May 20 1994Analytic results for the resistivity of the two-channel Kondo lattice in a particular infinite dimensional limit (Lorentzian density of states) are presented. It is argued that in the absence of symmetry breaking phase transitions or applied fields there ... More
Applied statistics: A reviewAug 27 2007The main phases of applied statistical work are discussed in general terms. The account starts with the clarification of objectives and proceeds through study design, measurement and analysis to interpretation. An attempt is made to extract some general ... More
Prevalence of Generic Laver DiamondMay 12 2014Viale \cite{Viale_GuessingModel} introduced the notion of Generic Laver Diamond at $\kappa$---which we denote $\Diamond_{\text{Lav}}(\kappa)$---asserting the existence of a single function from $\kappa \to H_\kappa$ that behaves much like a supercompact ... More
Forcing axioms, approachability, and stationary set reflectionJul 16 2018Apr 07 2019We prove a variety of theorems about stationary set reflection and concepts related to internal approachability. We prove that an implication of Fuchino-Usuba relating stationary reflection to a version of Strong Chang's Conjecture cannot be reversed; ... More
Phase diagram of the ferroelectric-relaxor (1-x)PbMg(1/3)Nb(2/3)O3-xPbTiO3Mar 20 2002Synchrotron x-ray powder diffraction measurements have been performed on unpoled ceramic samples of (1-x)PbMg(1/3)Nb(2/3)O3-xPbTiO3 (PMN-xPT) with 30%<= x<= 39% as a function of temperature around the morphotropic phase boundary (MPB), which is the line ... More
Layered posets and Kunen's universal collapseMay 30 2015Sep 29 2017We develop the theory of layered posets, and use the notion of layering to prove a new iteration theorem (Theorem 6): if $\kappa$ is weakly compact then any universal Kunen iteration of $\kappa$-cc posets (each possibly of size $\kappa$) is $\kappa$-cc, ... More
Selection Rules for Two Channel Kondo Models of U and Ce ions in MetalsAug 12 1992Aug 14 1992Symmetry based selection rules are developed providing minimal criteria for the existence of two-channel Kondo interactions between conduction electrons and the low energy degrees of freedom on U$^{4+}$ and Ce$^{3+}$ in a metal host, assuming that the ... More
Sliding charge density wave in manganitesMay 29 2007Jul 13 2007The so-called stripe phase of the manganites is an important example of the complex behaviour of metal oxides, and has long been interpreted as the localisation of charge at atomic sites. Here, we demonstrate via resistance measurements on La_{0.50}Ca_{0.50}MnO_3 ... More
Efficient Bayesian hierarchical functional data analysis with basis function approximations using Gaussian-Wishart processesDec 23 2015Dec 12 2016Functional data are defined as realizations of random functions (mostly smooth functions) varying over a continuum, which are usually collected with measurement errors on discretized grids. In order to accurately smooth noisy functional observations and ... More
Demonstration and interpretation of "scutoid" cells in a quasi-2D soap frothSep 22 2018Recently a novel type of epithelial cell has been discovered and dubbed the "scutoid". It is induced by curvature of the bounding surfaces. We show by simulations and experiments that such cells are to be found in a dry foam subjected to this boundary ... More
Hyperparameter Optimization and Boosting for Classifying Facial Expressions: How good can a "Null" Model be?Jun 14 2013One of the goals of the ICML workshop on representation and learning is to establish benchmark scores for a new data set of labeled facial expressions. This paper presents the performance of a "Null" model consisting of convolutions with random weights, ... More
Exotic Kondo Effects in Metals: Magnetic Ions in a Crystalline Electric Field and Tunneling CentersApr 10 1997Aug 28 1997This review article provides an overview of the physics of the two-channel Kondo impurity model as manifested in two-level systems in metals and certain actinide/lanthanide ions in metals. Basic models are presented, followed by a discussion of the multiplicative ... More
Naturalness made easy: two-loop naturalness bounds on minimal SM extensionsJul 25 2016The main result of this paper is a collection of conservative naturalness bounds on minimal extensions of the standard model by (vector-like) fermionic or scalar gauge multiplets. Within, we advocate for an intuitive and physical concept of naturalness ... More
Naturalness made easy: two-loop naturalness bounds on minimal SM extensionsJul 25 2016Feb 27 2017The main result of this paper is a collection of conservative naturalness bounds on minimal extensions of the standard model by (vector-like) fermionic or scalar gauge multiplets. Within, we advocate for an intuitive and physical concept of naturalness ... More
Design and interpretation of studies: relevant concepts from the past and some extensionsMay 10 2015Principles for the planning and analysis of observational studies, as suggested by W.G Cochran in 1972, are discussed and compared to additional methodological developments since then.
Concepts and a case study for a flexible class of graphical Markov modelsMar 06 2013With graphical Markov models, one can investigate complex dependences, summarize some results of statistical analyses with graphs and use these graphs to understand implications of well-fitting models. The models have a rich history and form an area that ... More
Graphical Markov models: overviewJul 29 2014May 04 2015We describe how graphical Markov models started to emerge in the last 40 years, based on three essential concepts that had been developed independently more than a century ago. Sequences of joint or single regressions and their regression graphs are singled ... More
Optimal Graphs for Independence and $k$-Independence PolynomialsOct 09 2017The independence polynomial $I(G,x)$ of a finite graph $G$ is the generating function for the sequence of the number of independent sets of each cardinality. We investigate whether, given a fixed number of vertices and edges, there exists optimally-least ... More
Spatial Multiplexing in a Cavity-Enhanced Quantum MemoryMar 06 2019We present a multiplexed quantum repeater protocol based on an ensemble of laser-cooled and trapped rubidium atoms inside an optical ring cavity. We have already demonstrated strong collective coupling in such a system and have constructed a multiplexing ... More
Very weak electron-phonon coupling and strong strain coupling in manganitesApr 19 2007Oct 19 2007The coupling of the manganite stripe phase to the lattice and to strain has been investigated via transmission electron microscopy studies of polycrystalline and thin film manganites. In polycrystalline \PCMOfiftwo a lockin to $q/a^*=0.5$ in a sample ... More
Bridging Phases at the Morphotropic Boundaries of Lead-Oxide Solid SolutionsNov 10 2005Ceramic solid solutions of PbZr(1-x)TixO3 (PZT) with compositions of about x= 0.50 are well-known for their extraordinarily large piezoelectric responses. The latter are highly anisotropic, and it was recently shown that, for the rhombohedral compositions ... More
Staggered Pairing Phenomenology for UPd_2Al_3 and UNi_2Al_3Jun 24 1997We apply the staggered-pairing Ginzburg-Landau phenomenology to describe superconductivity in UPd_2Al_3 and UNi_2Al_3. The phenomenology was applied successfully to UPt_3 so it explains why these materials have qualitatively different superconducting ... More
Radio observations of the cool gas, dust, and star formation in the first galaxiesJun 04 2010We summarize cm through submm observations of the host galaxies of z ~ 6 quasars. These observations reveal the cool molecular gas (the fuel for star formation), the warm dust (heated by star formation), the fine structure line emission (tracing the CNM ... More
Weak charge-lattice coupling requires reinterpretation of stripes of charge order in La1-xCaxMnO3Aug 27 2003Jan 26 2005Modulations in manganites attributed to stripes of charge/orbital/spin order are thought to result from strong electron-lattice interactions that lock the superlattice and parent lattice periodicities. Surprisingly in La1-xCaxMnO3(x>0.5, 90 K), convergent ... More
Regularity and Segre-Veronese embeddingsMay 29 2008This paper studies the regularity of certain coherent sheaves that arise naturally from Segre-Veronese embeddings of a product of projective spaces. We give an explicit formula for the regularity of these sheaves and show that their regularity is subadditive. ... More
Making a Science of Model SearchSep 23 2012Many computer vision algorithms depend on a variety of parameter choices and settings that are typically hand-tuned in the course of evaluating the algorithm. While such parameter tuning is often presented as being incidental to the algorithm, correctly ... More
A variant of Shelah's characterization of Strong Chang's ConjectureNov 15 2018Shelah considered a certain version of Strong Chang's Conjecture, which we denote $\text{SCC}^{\text{cof}}$, and proved that it is equivalent to several statements, including the assertion that Namba forcing is semiproper. We introduce an apparently weaker ... More
Indestructible Guessing Models and the ContinuumOct 18 2015Dec 14 2016We introduce a stronger version of an $\omega_1$-guessing model, which we call an indestructibly $\omega_1$-guessing model. The principle IGMP states that there are stationarily many indestructibly $\omega_1$-guessing models. This principle, which follows ... More
Martin's Maximum and tower forcingOct 07 2011Oct 18 2011There are several examples in the literature showing that compactness-like properties of a cardinal $\kappa$ cause poor behavior of some generic ultrapowers which have critical point $\kappa$ (Burke \cite{MR1472122} when $\kappa$ is a supercompact cardinal; ... More
Persistent localized states for a chaotically mixed bistable reactionAug 15 2006We describe the evolution of a bistable chemical reaction in a closed two-dimensional chaotic laminar flow, from a localized initial disturbance. When the fluid mixing is sufficiently slow, the disturbance may spread and eventually occupy the entire fluid ... More
Regular three-dimensional bubble clusters: shape, packing and growth-rateSep 04 2003Jan 16 2004We consider three-dimensional clusters of identical bubbles packed around a central bubble and calculate their energy and optimal shape. We obtain the surface area and bubble pressures to improve on existing growth laws for three-dimensional bubble clusters. ... More
A perturbation result for quasi-linear stochastic differential equations in UMD Banach spacesMar 07 2012We consider the effect of perturbations to a quasi-linear parabolic stochastic differential equation set in a UMD Banach space $X$. To be precise, we consider perturbations of the linear part, i.e. the term concerning a linear operator $A$ generating ... More
Pathwise space approximations of semi-linear parabolic SPDEs with multiplicative noiseDec 18 2018We provide convergence rates for space approximations of semi-linear stochastic differential equations with multiplicative noise in a Hilbert space. The space approximations we consider are spectral Galerkin and finite elements, and the type of convergence ... More
DJKM algebras I: Their Universal Central ExtensionSep 05 2010The purpose of this paper is to explicitly describe in terms of generators and relations the universal central extension of the infinite dimensional Lie algebra, $\mathfrak g\otimes \mathbb C[t,t^{-1},u|u^2=(t^2-b^2)(t^2-c^2)]$, appearing in the work ... More
Equations of Parametric Surfaces via SyzygiesOct 11 2000Feb 22 2001The revised version has two additional references and a shorter proof of Proposition 5.7. This version also makes numerous small changes and has an appendix containing a proof of the degree formula for a parametrized surface.
Secant varieties of toric varietiesFeb 16 2005Apr 27 2006Let $X_P$ be a smooth projective toric variety of dimension $n$ embedded in $\PP^r$ using all of the lattice points of the polytope $P$. We compute the dimension and degree of the secant variety $\Sec X_P$. We also give explicit formulas in dimensions ... More
Chromatic Polynomials of Oriented GraphsOct 12 2018Dec 20 2018The oriented chromatic polynomial of a oriented graph outputs the number of oriented $k$-colourings for any input $k$. We fully classify those oriented graphs for which the oriented graph has the same chromatic polynomial as the underlying simple graph, ... More
Club Chang's ConjectureSep 25 2018Oct 08 2018Chang's Conjecture (CC) asserts that for every $F:[\omega_2]^{<\omega} \to \omega_2$, there exists an $X$ that is closed under $F$ such that $|X|=\omega_1$ and $|X \cap \omega_1| =\omega$. By classic results of Silver and Donder, CC is equiconsistent ... More
Indestructibility of generically strong cardinalsMar 25 2014Aug 03 2015Foreman proved the Duality Theorem, which gives an algebraic characterization of certain ideal quotients in generic extensions. As an application he proved that generic supercompactness of $\omega_1$ is preserved by any proper forcing. We generalize portions ... More
Remarks on the accuracy of algorithms for motion by mean curvature in bounded domainsMar 26 2008Apr 18 2008Simulations of motion by mean curvature in bounded domains, with applications to bubble motion and grain growth, rely upon boundary conditions that are only approximately compatible with the equation of motion. Three closed form solutions for the problem ... More
Strain control of superlattice implies weak charge-lattice coupling in La$_{0.5}$Ca$_{0.5}$MnO$_3$Apr 19 2005Sep 09 2005We have recently argued that manganites do not possess stripes of charge order, implying that the electron-lattice coupling is weak [Phys Rev Lett \textbf{94} (2005) 097202]. Here we independently argue the same conclusion based on transmission electron ... More
Evolution of the Stellar Mass Tully-Fisher Relation in Disk Galaxy Merger SimulationsFeb 03 2009Dec 03 2009There is a large observational scatter toward low velocities in the stellar mass Tully-Fisher relation if disturbed and compact objects are included. However, this scatter can be eliminated if one replaces rotation velocity with $\rm S_{\rm 0.5}$, a quantity ... More
Theory of "ferrisuperconductivity" in $U_{1-x}Th_xBe_{13}$Jul 08 1999We construct a two component Ginzburg-Landau theory with coherent pair motion and incoherent quasiparticles for the phase diagram of $U_{1-x}Th_xBe_{13}$. The two staggered superconducting states live at the Brillouin zone center and the zone boundary, ... More
Superconductivity in the Anderson LatticeMay 25 1993Using an anisotropic hybridization matrix element, V($\vec k$), reflecting cubic symmetry at the ``rare-earth'' sites of the infinite U Anderson lattice, we calculate the bare quasiparticle scattering amplitude to order 1/N using slave Bosons and find ... More
The Herschel view of the nebula around the luminous blue variable star AG CarinaeApr 13 2015Far-infrared Herschel PACS imaging and spectroscopic observations of the nebula around the luminous blue variable (LBV) star AG Car have been obtained along with optical imaging in the Halpha+[NII] filter. In the infrared light, the nebula appears as ... More
One-, Two-, and Three-channel Kondo effects for a model Ce$^{3+}$ Impurity in a MetalAug 29 1995We present studies of a simple Anderson model Hamiltonian for Ce$^{3+}$ ions in cubic symmetry with three configurations ($f^0$,$f^1$,$f^2$). Our Hamiltonian includes: (i) One-channel Anderson model; (ii) Two-channel Anderson model. Using the third order ... More
Evaluating the role of data quality when sharing information in hierarchical multi-stock assessment models, with an application to Dover SoleApr 10 2018Oct 20 2018An emerging approach to data-limited fisheries stock assessment uses hierarchical multi-stock assessment models to group stocks together, sharing information from data-rich to data-poor stocks. In this paper, we simulate data-rich and data-poor fishery ... More
Phase Diagram of the Two-Channel Kondo LatticeSep 20 1996The phase diagram of the two-channel Kondo lattice model is examined with a Quantum Monte Carlo simulation in the limit of infinite dimensions. Commensurate (and incommensurate) antiferromagnetic and superconducting states are found. The antiferromagnetic ... More
The Hubbard Model at Infinite Dimensions: Thermodynamic and Transport PropertiesAug 11 1992We present results on thermodynamic quantities, resistivity and optical conductivity for the Hubbard model on a simple hypercubic lattice in infinite dimensions. Our results for the paramagnetic phase display the features expected from an intuitive analysis ... More
Machine Vision and Deep Learning for Classification of Radio SETI SignalsFeb 06 2019We apply classical machine vision and machine deep learning methods to prototype signal classifiers for the search for extraterrestrial intelligence. Our novel approach uses two-dimensional spectrograms of measured and simulated radio signals bearing ... More
A unifying class of Skorokhod embeddings: connecting the Azema-Yor and Vallois embeddingsJun 02 2005In this paper we consider the Skorokhod embedding problem in Brownian motion. In particular, we give a solution based on the local time at zero of a variably skewed Brownian motion related to the underlying Brownian motion. Special cases of the construction ... More
Implicitization of surfaces in P^3 in the presence of base pointsMay 23 2002Apr 29 2003We show that the method of moving quadrics for implicitizing surfaces in P^3 applies in certain cases where base points are present. However, if the ideal defined by the parametrization is saturated, then this method rarely applies. Instead, we show that ... More
Measuring and Understanding Sensory Representations within Deep Networks Using a Numerical Optimization FrameworkFeb 17 2015A central challenge in sensory neuroscience is describing how the activity of populations of neurons can represent useful features of the external environment. However, while neurophysiologists have long been able to record the responses of neurons in ... More
A Simple Model for Coupled Magnetic and Quadrupolar Instabilities in Uranium Heavy-Fermion MaterialsSep 08 1992We present a mean-field calculation of the phase diagram of a simple model of localized moments, in the hexagonal uranium heavy-fermion compounds. The model considers a non-Kramers quadrupolar doublet ground state magnetically coupled with a singlet excited-state, ... More
Self-consistent Treatment of Crystal-Electric-Field-Levels in the Anderson LatticeSep 17 1996We consider an Anderson lattice model with a spin 1/2 degenerated conduction electron band and localized ionic CEF-levels, classified according to the irreducible representation of the point group of the lattice. We present the self-consistency equations ... More
An Optimal Skorokhod Embedding for DiffusionsDec 12 2002Given a Brownian motion $B_t$ and a general target law $\mu$ (not necessarily centered or even integrable) we show how to construct an embedding of $\mu$ in $B$. This embedding is an extension of an embedding due to Perkins, and is optimal in the sense ... More
Low symmetry phases in piezoelectric systems: PZN-xPT single crystal and powderSep 28 2001In this review we address some of the experimental challenges found in the x-ray diffraction characterization of the low-symmetry phases recently discovered in the PZT, PZN-PT and PMN-PT piezoelectric systems around their morphotropic phase boundaries. ... More
Transport Properties of the Infinite Dimensional Hubbard ModelAug 05 1992Results for the optical conductivity and resistivity of the Hubbard model in infinite spatial dimensions are presented. At half filling we observe a gradual crossover from a normal Fermi-liquid with a Drude peak at $\omega=0$ in the optical conductivity ... More
Low-temperature phases in Pb(Zr0.52Ti0.48)O3: A neutron powder diffraction studyAug 09 2004A neutron powder diffraction study has been carried out on Pb(Zr0.52Ti0.48)O3 in order to resolve an ongoing controversy about the nature of the low-temperature structure of this strongly-piezoelectric and technologically-important material. The results ... More
Interpretation of interaction: A reviewDec 07 2007Several different types of statistical interaction are defined and distinguished, primarily on the basis of the nature of the factors defining the interaction. Illustrative examples, mostly epidemiological, are given. The emphasis is primarily on interpretation ... More
Theory of One-Channel vs. Multi-Channel Kondo Effects for Ce$^{3+}$ ImpuritiesDec 05 1994Aug 07 1995We introduce a model for Ce$^{3+}$ impurities in cubic metals which exhibits competition between the Fermi-liquid fixed point of the single channel Kondo model and the non-Fermi-liquid fixed point of the two- and three-channel Kondo models. Using the ... More
Scaling analysis of a model Hamiltonian for Ce$^{3+}$ impurity in a cubic metalMar 05 1996Mar 11 1996We introduce various exchange interactions in a model Hamiltonian for Ce$^{3+}$ ions in cubic symmetry with three configurations ($f^0$,$f^1$,$f^2$). With the impurity pseudo spin $S_I=1/2$, our Hamiltonian includes: (i) One-channel $S_c=1/2$ Anderson ... More
Thermal Emission from Warm Dust in the Most Distant QuasarsJun 18 2008Aug 06 2008We report new continuum observations of fourteen z~6 quasars at 250 GHz and fourteen quasars at 1.4 GHz. We summarize all recent millimeter and radio observations of the sample of the thirty-three quasars known with 5.71<=z<=6.43, and present a study ... More
On Closed Graphs IJun 21 2013Dec 31 2014A graph is closed when its vertices have a labeling by [n] with a certain property first discovered in the study of binomial edge ideals. In this article, we prove that a connected graph has a closed labeling if and only if it is chordal, claw-free, and ... More
Regularity and convergence analysis in Sobolev and Hölder spaces for generalized Whittle-Matérn fieldsApr 13 2019We analyze several Galerkin approximations of a Gaussian random field $\mathcal{Z}\colon\mathcal{D}\times\Omega\to\mathbb{R}$ indexed by a Euclidean domain $\mathcal{D}\subset\mathbb{R}^d$ whose covariance structure is determined by a negative fractional ... More
Diagrammatic Kazhdan-Lusztig theory for the (walled) Brauer algebraSep 21 2010We determine the decomposition numbers for the Brauer and walled Brauer algebra in characteristic zero in terms of certain polynomials associated to cap and curl diagrams (recovering a result of Martin in the Brauer case). We consider a second family ... More
Moment Maps, Strict Linear Precision, and Maximum Likelihood Degree OneOct 08 2018We study the moment maps of a smooth projective toric variety. In particular, we characterize when the moment map coming from the quotient construction is equal to a weighted Fubini-Study moment map. This leads to an investigation into polytopes with ... More
3D MHD Modeling of the Gaseous Structure of the Galaxy: Setup and Initial ResultsJul 29 2002We show the initial results of our 3D MHD simulations of the flow of the Galactic atmosphere as it responds to a spiral perturbation in the potential. In our standard case, as the gas approaches the arm, there is a downward converging flow that terminates ... More
Imaginary crystal bases for $U_q(\widehat{\mathfrak{sl}(2)})$-modules in category $\mathcal O^q_{\text{red,im}}$Dec 04 2018Recently we defined imaginary crystal bases for $U_q(\widehat{\mathfrak{sl}(2)})$- modules in category $\mathcal O^q_{\text{red,im}}$ and showed the existence of such bases for reduced quantized imaginary Verma modules for $U_q(\widehat{\mathfrak{sl}(2)})$. ... More
Local Lipschitz continuity in the initial value and strong completeness for nonlinear stochastic differential equationsSep 22 2013Nov 24 2014Recently, Hairer et. al (2012) showed that there exist SDEs with infinitely often differentiable and globally bounded coefficient functions whose solutions fail to be locally Lipschitz continuous in the strong L^p-sense with respect to the initial value ... More
Laser cooling of trapped ytterbium ions with an ultraviolet diode laserNov 29 2005We demonstrate an ultraviolet diode laser system for cooling of trapped ytterbium ions. The laser power and linewidth are comparable to previous systems based on resonant frequency doubling, but the system is simpler, more robust, and less expensive. ... More
Limitations of the Standard Gravitational Perfect Fluid ParadigmMar 25 2009Sep 16 2010We show that the standard perfect fluid paradigm is not necessarily a valid description of a curved space steady state gravitational source. Simply by virtue of not being flat, curved space geometries have to possess intrinsic length scales, and such ... More
Incorporating multi-body effects in SAFT by improving the description of the reference system. I. Mean activity correction for cluster integrals in the reference systemJan 18 2016A system of patchy colloidal particles interacting with a solute that can associate multiple times in any direction is a useful model for patchy colloidal mixtures. Despite the simplicity of the interaction, because of the presence of multi-body correlations ... More
Quantum Effects in the Nonlinear Response of Graphene PlasmonsApr 11 2017The ability of graphene to support long-lived, electrically tunable plasmons that interact strongly with light, combined with its highly nonlinear optical response, has generated great expectations for application of the atomically-thin material to nanophotonic ... More
Dirty Peierls transitions in alpha-UraniumNov 13 2006We point out that a recent model for the heat capacity of alpha-U that invokes CDW collective modes is unphysical. We show instead that the features in the heat capacity of both single-crystal and polycrystalline alpha-U can be accounted for by a number ... More
Robust Hedging of Options on a Leveraged Exchange Traded FundFeb 23 2017A leveraged exchange traded fund (LETF) is an exchange traded fund that uses financial derivatives to amplify the price changes of a basket of goods. In this paper, we consider the robust hedging of European options on a LETF, finding model-free bounds ... More
A neural network trained to predict future video frames mimics critical properties of biological neuronal responses and perceptionMay 28 2018May 30 2018While deep neural networks take loose inspiration from neuroscience, it is an open question how seriously to take the analogies between artificial deep networks and biological neuronal systems. Interestingly, recent work has shown that deep convolutional ... More
Discrete solitons in electromechanical resonatorsJul 31 2009We consider a parametrically driven Klein--Gordon system describing micro- and nano-devices, with integrated electrical and mechanical functionality. Using a multiscale expansion method we reduce the system to a discrete nonlinear Schrodinger equation. ... More
Decomposition Techniques for Bilinear Saddle Point Problems and Variational Inequalities with Affine Monotone Operators on Domains Given by Linear Minimization OraclesJun 08 2015Oct 02 2015The majority of First Order methods for large-scale convex-concave saddle point problems and variational inequalities with monotone operators are proximal algorithms which at every iteration need to minimize over problem's domain X the sum of a linear ... More
The conjugacy ratio of groupsSep 07 2017In this paper we introduce and study the conjugacy ratio of a finitely generated group, which is the limit at infinity of the quotient of the conjugacy and standard growth functions. We conjecture that the conjugacy ratio is $0$ for all groups except ... More
An imaginary PBW basis for quantum affine algebras of type 1Jul 10 2013Mar 28 2014Let $\hat{\mathfrak g}$ be an affine Lie algebra of type 1. We give a PBW basis for the quantum affine algebra $U_q(\hat{\mathfrak g})$ with respect to the triangular decomposition of $\hat{\mathfrak g}$ associated with the imaginary positive root system. ... More
The structure of non-linear martingale optimal transport problemsMar 15 2019We explore the structure of solutions to a family of non-linear martingale optimal transport (MOT) problems that involve conditional expectations in the objective functional. En route general results concerning optimization over (martingale) measures ... More
Detecting Higgs bosons in the bb decay channel using forward proton tagging at the LHCSep 19 2007A detailed study is presented of the search for Higgs bosons in the b-decay channel in the central exclusive production process at the LHC. We present results for proton tagging detectors at both 220m and 420m around ATLAS or CMS. We consider two benchmark ... More
An Anderson Impurity Model for Efficient Sampling of Adiabatic Potential Energy Surfaces of Transition Metal ComplexesJun 09 2004We present a model intended for rapid sampling of ground and excited state potential energy surfaces for first-row transition metal active sites. The method is computationally inexpensive and is suited for dynamics simulations where (1) adiabatic states ... More
Discovery of multiple dust shells beyond 1 arcmin in the circumstellar envelope of IRC+10216 using Herschel/PACSOct 12 2012We present new Herschel/PACS images at 70, 100, and 160 micron of the well-known, nearby, carbon-rich asymptotic giant branch star IRC+10216 revealing multiple dust shells in its circumstellar envelope. For the first time, dust shells (or arcs) are detected ... More
Minnorm training: an algorithm for training over-parameterized deep neural networksJun 03 2018Jun 21 2018In this work, we propose a new training method for finding minimum weight norm solutions in over-parameterized neural networks (NNs). This method seeks to improve training speed and generalization performance by framing NN training as a constrained optimization ... More
Nonlinear atom-plasmon interactions enabled by nanostructured grapheneMar 26 2019Electrically tunable graphene plasmons are anticipated to enable strong light-matter interactions with resonant quantum emitters. However, plasmon resonances in graphene are typically limited to infrared frequencies, below those of optical excitations ... More