Results for "Timothy Lovorn"

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Charge pair hopping and Bose-Einstein condensation in underdoped Mott insulatorsDec 06 2010Recently, we have solved the long-standing problem of connecting the physics of the Mott insulator to the underdoped regime of the t-J model [PRB 82, 014504, 2010]. We have derived a renormalized Hamiltonian valid for small doping (x) which is characterized ... More
A Consistent Theory of Underdoped Cuprates: Evolution of the RVB State From Half FillingOct 12 2009Oct 18 2009We have been able to resolve two long-standing issues that are central to the theory of high Tc superconductivity: (1) How is the physics of the doped region connected to that of the Mott insulator? (2) What is the origin of the two-dimensionality of ... More
Topological Exciton Bands in Moiré HeterojunctionsOct 12 2016Moir\'e patterns are common in Van der Waals heterostructures and can be used to apply periodic potentials to elementary excitations. We show that the optical absorption spectrum of transition metal dichalcogenide bilayers is profoundly altered by long ... More
Tunable $Γ- K$ Valley Populations in Hole-Doped Trilayer WSe$_2$Jan 10 2018We present a combined experimental and theoretical study of valley populations in the valence bands of trilayer WSe$_2$. Shubnikov$-$de Haas oscillations show that trilayer holes populate two distinct subbands associated with the $K$ and $\Gamma$ valleys, ... More
Ionic Binding in a Susy BackgroundNov 01 2006Jun 08 2007From string theory and the observation of a positive vacuum energy in our universe it seems inevitable that there will eventually be a phase transition to an exactly supersymmetric (susy) universe. In this phase there will be an effective weakening of ... More
Emergence of Topologically Protected Helical States in Minimally Twisted Bilayer GrapheneFeb 08 2018Bilayer graphene samples in which inversion symmetry is broken have quantum valley Hall ground states that support counterpropogating topologically protected helical (TPH) edge states localized along domain walls between AB and BA stacking regions. Moreover, ... More
Computing area in group presentationsJun 28 2016Jul 23 2016The width of a word $w$ representing an element in a free group $F(a,b)$ was defined by Jiang to be the minimal $N$ such that $w$ freely equals a product of $N$ conjugates of powers of $a$ and $b$. In 1991 Grigorchuk and Kurchanov gave an algorithm computing ... More
Nonparametric Stochastic Discount Factor DecompositionDec 15 2014Aug 19 2016Stochastic discount factor (SDF) processes in dynamic economies admit a permanent-transitory decomposition in which the permanent component characterizes pricing over long investment horizons. This paper introduces econometric methods to extract the permanent ... More
Quantum Solitons in Affine Toda Field TheoriesOct 03 1991The spectra of $A_r$ affine Toda field theories with imaginary coupling constant, are investigated. Soliton solutions are found, which, despite the non-unitary form of the Lagrangian, have real classical masses and are stable to small perturbations. The ... More
Wilson Loop Area Law for 2D Yang-Mills in Generalized Axial GaugeJan 18 2016Jul 25 2016We prove that Wilson loop expectation values for arbitrary simple closed contours obey an area law up to second order in perturbative two-dimensional Yang-Mills theory. Our analysis occurs within a general family of axial-like gauges, which include and ... More
$\mathcal{S}$-categories, $\mathcal{S}$-groupoids, Segal categories and quasicategoriesJan 21 2004The notes were prepared for a series of talks that I gave in Hagen in late June and early July 2003, and, with some changes, in the University of La Lagu\~{n}a, the Canary Islands, in September, 2003. They aim (i) to revisit some oldish material on abstract ... More
What `shape' is space-time?Oct 22 2002Some examples from the mathematics of shape are presented that question some of the almost hidden assumptions behind results on limiting behaviour of finitary approximations to space-time. These are presented so as to focus attention on the observational ... More
Bootstrapping Deep Lexical Resources: Resources for CoursesSep 15 2007We propose a range of deep lexical acquisition methods which make use of morphological, syntactic and ontological language resources to model word similarity and bootstrap from a seed lexicon. The different methods are deployed in learning lexical items ... More
A Class of Profinite Hopf-Galois Extensions Over QOct 14 2016Nov 18 2016For $p$ a prime and $a\in\mathbb{Q}$, where $a$ is not a $p^n$-th power of any rational number, the extension $\mathbb{Q}(w_n)/\mathbb{Q}$ where $w_n=\root p^n \of a$ is separable but non-normal. The Hopf-Galois theory for separable extensions was determined ... More
Regularity of Extremal Functions in Weighted Bergman and Fock Type SpacesNov 07 2014We discuss the regularity of extremal functions in certain weighted Bergman and Fock type spaces. Given an appropriate analytic function $k$, the corresponding extremal function is the function with unit norm maximizing $\text{Re} \int_\Omega f(z) \overline{k(z)}\, ... More
Death and extended persistence in computational algebraic topologySep 04 2016The main aim of this paper is to explore the ideas of persistent homology and extended persistent homology, and their stability theorems, using ideas from [Bubenik and Scott, 2014; Cohen-Steiner, Edelsbrunner, and Harer, 2007; and Cohen-Steiner, Edelsbrunner, ... More
The Dirichlet Problem for Einstein Metrics on Cohomogeneity One ManifoldsOct 05 2017Let $G/H$ be a compact homogeneous space, and let $\hat{g}_0$ and $\hat{g}_1$ be $G$-invariant Riemannian metrics on $G/H$. We consider the problem of finding a $G$-invariant Einstein metric $g$ on the manifold $G/H\times [0,1]$ subject to the constraint ... More
Ricci flow from some spaces with asymptotically cylindrical singularitiesMay 23 2018We prove the existence of Ricci flow starting from a class of metrics with unbounded curvature, which are doubly-warped products over an interval with a spherical factor pinched off at an end. These provide a forward evolution from some known and conjectured ... More
The Perturbative Approach to Path Integrals: A Succinct Mathematical TreatmentMay 18 2015Sep 29 2016We study finite-dimensional integrals in a way that elucidates the mathematical meaning behind the formal manipulations of path integrals occurring in quantum field theory. This involves a proper understanding of how Wick's theorem allows one to evaluate ... More
The Seiberg-Witten Equations on Manifolds with Boundary II: Lagrangian Boundary Conditions for a Floer TheoryAug 11 2010Jun 01 2016In this paper, we study the Seiberg-Witten equations on the product R x Y, where Y is a compact 3-manifold with boundary. Following the approach of Salamon and Wehrheim in the instanton case, we impose Lagrangian boundary conditions for the Seiberg- Witten ... More
Reid's recipe and derived categoriesDec 24 2008May 15 2012We prove two existing conjectures which describe the geometrical McKay correspondence for a finite abelian G in SL3(C) such that C^3/G has a single isolated singularity. We do it by studying the relation between the derived category mechanics of computing ... More
Derived McKay correspondence via pure-sheaf transformsJun 30 2006Feb 04 2008In most cases where it had been shown to exist the derived McKay correspondence D(Y) --> D^G(C^n) can be written as a Fourier-Mukai transform which sends point sheaves of the crepant resolution Y to pure sheaves in D^G(C^n). We give a sufficient condition ... More
Some non-abelian covers of knots with non-trivial Alexander polynomialFeb 18 2019Let $K$ be a tame knot embedded in $\mathbf{S}^3$. We address the problem of finding the minimal degree non-cyclic cover $p:X \rightarrow \mathbf{S}^3 \smallsetminus K$. When $K$ has non-trivial Alexander polynomial we construct finite non-abelian representations ... More
Quantum Soliton Mass Corrections in SL(N) Affine Toda TheorySep 08 1992The first quantum mass corrections for the solitons of complex $sl(n)$ affine Toda field theory are calculated. The corrections are real and preserve the classical mass ratios. The formalism also proves that the solitons are classically stable.
Finiteness and Paradoxical Decompostions in C*-Dynamical SystemsFeb 21 2015We discuss the interplay between K-theoretical dynamics and the structure theory for certain C*-algebras arising from crossed products. For noncommutative C*-systems we present notions of minimality and topological transitivity in the K-theoretic framework ... More
On Milgram's construction and the Duke embedding conjecturesMar 10 2013Apr 18 2013Milgram constructed a 28-vertex cubic graph of genus 4 that disproved Duke's conjecture relating Betti number to minimum genus. We apply Milgram's method to construct to find graphs of higher genus violating Duke's conjecture, which gives a sharper bound ... More
On primes of the form $n_1^u + n_2^v + k$, on averageFeb 07 2012Oct 03 2012We use the Hardy-Littlewood circle method to study primes of the form $n_1^u + n_2^v + k$, on average.
The Bouniakowsky conjecture and the density of polynomial roots to prime moduliJun 06 2009We establish a result linking the Bouniakowsky conjecture and the density of polynomial roots to prime moduli.
From abstract alpha-Ramsey theory to abstract ultra-Ramsey theoryJan 15 2016We work within the framework of the Alpha-Theory introduced by Benci and Di Nasso. The Alpha-Theory postulates a few natural properties for an infinite "ideal" number $\alpha$. The formulation provides an elementary axiomatics for the methods of abstract ... More
Quantum Yang-Mills Theory in Two Dimensions: Exact versus PerturbativeAug 25 2015Sep 07 2016The standard Feynman diagrammatic approach to quantum field theories assumes that perturbation theory approximates the full quantum theory at small coupling even when a mathematically rigorous construction of the latter is absent. On the other hand, two-dimensional ... More
Families of G-constellations over resolutions of quotient singularitiesMay 14 2003Let G be a finite subgroup of GL_n(C). A study is made of the ways in which resolutions of the quotient space C^n / G can parametrise G-constellations, that is, G-regular finite length sheaves. These generalise G-clusters, which are used in the McKay ... More
Dissecting Equilateral Triangles into Non-Congruent Equilateral Triangles: A Novel Proof of Tutte's ResultDec 15 2014In this paper, we show that an equilateral triangle cannot be dissected into finitely many smaller equilateral triangles, no two of which share two vertices. We do this without the use of Electrical Networks.
Exposing the Hidden Web: An Analysis of Third-Party HTTP Requests on 1 Million WebsitesNov 02 2015This article provides a quantitative analysis of privacy-compromising mechanisms on 1 million popular websites. Findings indicate that nearly 9 in 10 websites leak user data to parties of which the user is likely unaware; more than 6 in 10 websites spawn ... More
Selective but not RamseyDec 19 2013We give a partial answer to the following question of Dobrinen: For a given topological Ramsey space $\mathcal{R}$, are the notions of selective for $\mathcal{R}$ and Ramsey for $\mathcal{R}$ equivalent? Every topological Ramsey space $\mathcal{R}$ has ... More
Bounds on Integral Means of Bergman Projections and their DerivativesMar 13 2015Sep 29 2016We bound integral means of the Bergman projection of a function in terms of integral means of the original function. As an application of these results, we bound certain weighted Bergman space norms of derivatives of Bergman projections in terms of weighted ... More
Wilson Loop Area Law for 2D Yang-Mills in Generalized Axial GaugeJan 18 2016Feb 21 2018We prove that Wilson loop expectation values for arbitrary simple closed contours obey an area law up to second order in perturbative two-dimensional Yang-Mills theory. Our analysis occurs within a general family of axial-like gauges, which include and ... More
Lagrangian correspondences and Donaldson's TQFT construction of the Seiberg-Witten invariants of 3-manifoldsNov 15 2011Sep 08 2013Using Morse-Bott techniques adapted to the gauge-theoretic setting, we show that the limiting boundary values of the space of finite energy monopoles on a connected 3-manifold with at least two cylindrical ends provides an immersed Lagrangian submanifold ... More
Gram's Law Fails a Positive Proportion of the TimeNov 06 2008This paper extends the work done by Titchmarsh on Gram's Law (an attempt to locate the zeroes of the zeta-function on the critical line). Herewith it is shown that a positive proportion of Gram intervals violate Gram's Law; and also that a weaker notion ... More
An introduction to varieties in weighted projective spaceApr 08 2016Apr 17 2016Weighted projective space arises when we consider the usual geometric definition for projective space and allow for non-trivial weights. On its own, this extra freedom gives rise to more than enough interesting phenomena, but it is the fact that weighted ... More
Structural Properties of ${\cal R}_2$ Part IMar 07 2016This is the first of two papers establishing structural properties of ${\cal R}_2$.
On the sum of integers from some multiplicative sets and some powers of integersOct 17 2016We show that if there exists an integer subject to some congruence conditions that cannot be written as the sum of the norm of an ideal in $\mathbb{Z}[\exp(2\pi i/2^k)]$ and at most $k$ powers of $2$, $k\geq 3$, then there are infinitely many such integers. ... More
A Class of Profinite Hopf-Galois Extensions Over QOct 14 2016For $p$ a prime and $a\in\mathbb{Q}$, where $a$ is not a $p^n$-th power of any rational number, the extension $\mathbb{Q}(w_n)/\mathbb{Q}$ where $w_n=\root p^n \of a$ is separable but non-normal. The Hopf-Galois theory for separable extensions was determined ... More
On the Discrepancy of the Roots of $x^2+1$ and $x^2+2$ to Prime ModuliMar 07 2011Oct 03 2012In this paper, we make a conjecture (conjecture 1) related to the Bateman-Horn conjecture and proceed to study the roots of $x^2+1$ and $x^2+2$ to prime moduli, assuming the truth of the Bateman-Horn conjecture and conjecture 1 and using the Erd\H{o}s-Turan-Koksma ... More
A note on the lattice Dirac-Kaehler equationJul 18 1995A lattice version of the Dirac-Kaehler equation (DKE) describing fermions was discussed in articles by Becher and Joos. The decomposition of lattice Dirac-Kaehler fields (inhomogeneous cochains) to lattice Dirac fields remained as an open problem. I show ... More
On the parity of the multiplicative order of certain products of integers related to Gauss factorialsMar 08 2016Mar 15 2016In this note, we prove that under some conditions, certain products of integers related to Gauss factorials are always quadratic residues.
On the sum of integers from some multiplicative sets and some powers of integersOct 17 2016Oct 18 2016We show that if there exists an integer subject to some congruence conditions that cannot be written as the sum of the norm of an ideal in $\mathbb{Z}[\exp(2\pi i/2^k)]$ and at most $k$ powers of $2$, $k\geq 3$, then there are infinitely many such integers. ... More
A symplectic Gysin sequenceJul 11 2008We use the theory of pseudo-holomorphic quilts to establish a counterpart, in symplectic Floer homology, to the Gysin sequence for the homology of a sphere-bundle. In a motivating class of examples, this "symplectic Gysin sequence" is precisely analogous ... More
Tropical Vertex-Disjoint Cycles of a Vertex-Colored Digraph (TROPICAL EXCHANGE) is NP-CompleteOct 14 2016Given a directed graph, it is known that the problem of finnding a set of vertex-disjoint cycles with the maximum total number of vertices (MAX SIZE EXCHANGE) can be solved in polynomial time. Given a vertex-colored graph, if a set of vertices contains ... More
Natural G-Constellation FamiliesDec 31 2005Dec 25 2008Let G be a finite subgroup of GL_n(C). G-constellations are a scheme-theoretic generalization of orbits of G in C^n. We study flat families of G-constellations parametrised by an arbitrary resolution of the quotient space C^n/G. We develop a geometrical ... More
Improvements to Turing's MethodMar 11 2009Aug 05 2010This paper refines the argument of Lehman by reducing the size of the constants in Turing's method. This improvement is given in Theorem 1 and scope for further improvements is also given. Analogous improvements to Dirichlet L-functions and Dedekind zeta-functions ... More
Ramsey for $\mathcal{R}_{1}$ ultrafilter mappings and their Dedekind cutsJan 13 2014Associated to each ultrafilter $\mathcal{U}$ on $\omega$ and each map $p:\omega\rightarrow \omega$ is a Dedekind cut in the ultrapower $\omega^{\omega}/p( \mathcal{U})$. Blass has characterized, under CH, the cuts obtainable when $\mathcal{U}$ is taken ... More
Bergman-Hölder Functions, Area Integral Means and Extremal ProblemsAug 02 2016We study certain weighted area integral means of analytic functions in the unit disc. We relate the growth of these means to the property of being mean H\"older continuous with respect to the Bergman space norm. In contrast with earlier work, we use the ... More
Extremal Problems in Bergman Spaces and an Extension of Ryabykh's $H^p$ Regularity Theorem For $1<p<\infty$Feb 05 2015We study linear extremal problems in the Bergman space $A^p$ of the unit disc, where $1 < p < \infty$. Given a functional on the dual space of $A^p$ with representing kernel $k \in A^q$, where $1/p + 1/q = 1$, we show that if $q \le q_1 < \infty$ and ... More
The Prouhet-Tarry-Escott problem for Gaussian integersNov 04 2010Feb 13 2011Given natural numbers $n$ and $k$, with $n>k$, the Prouhet-Tarry-Escott (PTE) problem asks for distinct subsets of $\Z$, say $X=\{x_1,...,x_n\}$ and $Y=\{y_1,...,y_n\}$, such that \[x_1^i+...+x_n^i=y_1^i+...+y_n^i\] for $i=1,...,k$. Many partial solutions ... More
Adaptive testing on a regression function at a pointAug 15 2014Oct 14 2015We consider the problem of inference on a regression function at a point when the entire function satisfies a sign or shape restriction under the null. We propose a test that achieves the optimal minimax rate adaptively over a range of H\"{o}lder classes, ... More
Stochastic Feynman Rules for Yang-Mills Theory on the PlaneJul 25 2016We analyze quantum Yang-Mills theory on $\mathbb{R}^2$ using a novel discretization method based on an algebraic analogue of stochastic calculus. Such an analogue involves working with "Gaussian" free fields whose covariance matrix is indefinite rather ... More
Structural Properties of ${\cal R}_2$ Part IIMar 07 2016This is the second of two papers establishing structural properties of ${\cal R}_2$.
Anisotropic Function Spaces and Elliptic Boundary Value ProblemsOct 19 2010Mar 01 2011In this paper, we study anisotropic Bessel potential and Besov spaces, where the anisotropy measures the extra amount of regularity in certain directions. Some basic properties of these spaces are established along with applications to elliptic boundary ... More
The Analytic Structure of Trigonometric S MatricesMay 11 1993May 17 1993$S$-matrices associated to the vector representations of the quantum groups for the classical Lie algebras are constructed. For the $a_{m-1}$ and $c_m$ algebras the complete $S$-matrix is found by an application of the bootstrap equations. It is shown ... More
A Pohozaev Identity on Warped Product SolitonsFeb 02 2016Mar 10 2016Warped product metrics are a class of Riemannian metrics on cross products $B \times F$ which have been well studied and provide a rich set of examples. In this paper we consider shrinking gradient Ricci solitons which are warped product metrics. We prove ... More
Ricci Flow Emerging from Rotationally Symmetric Degenerate NeckpinchesNov 13 2014Feb 05 2015In previous work, Angenent, Isenberg, and Knopf created type-II Ricci flow neckpinch singularities. In this paper we construct solutions to Ricci flow whose initial data is the singular metric resulting from these singularities. We show in particular ... More
Towards in-situ cleaning of a trapped ion quantum computerJul 08 2012Sep 08 2012A plasma glow discharge system was created using a conventional microwave oven to ignite and maintain the plasma. The system was used for plasma cleaning and its properties were analysed to assess its viability for removing surface contaminants, which ... More
Analysis of a Double Kruskal TheoremMar 07 2016The strength of an extension of Kruskal's Theorem to certain pairs of cohabitation trees is calibrated.
Formal Homotopy Quantum Field Theories, II : Simplicial Formal MapsDec 01 2005Simplicial formal maps were introduced in the first paper, (math.QA/0512032), of this series as a tool for studying Homotopy Quantum Field Theories with background a general homotopy 2-type. Here we continue their study, showing how a natural generalisation ... More
Continuity of the asymptotics of expected zeros of fewnomialsNov 27 2013In "Random complex fewnomials, I," B. Shiffman and S. Zelditch determine the limiting formula as N goes to infinity of the (normalized) expected distribution of complex zeros of a system of k random n-nomials in m variables where the coefficients are ... More
A modest improvement on the function $S(T)$Oct 21 2010This paper contains a small improvement to the explicit bounds on the growth of the function $S(T)$. It is shown how more substantial improvements are possible if one has better explicit bounds on the growth of $|\zeta(\frac{1}{2}+it)|$.
Continuity of Extremal Elements in Uniformly Convex SpacesJan 30 2013In this paper, we study the problem of finding the extremal element for a linear functional over a uniformly convex Banach space. We show that a unique extremal element exists and depends continuously on the linear functional, and vice versa. Using this, ... More
Solution of Extremal Problems in Bergman Spaces Using the Bergman ProjectionNov 21 2013In this paper we discuss the explicit solution of certain extremal problems in Bergman spaces. In order to do this, we develop methods to calculate the Bergman projections of various functions. As a special case, we deal with canonical divisors for certain ... More
Hopf-Galois Structures Arising From Groups with Unique Subgroup of Order pMay 19 2014Aug 07 2014For $\Gamma$ a group of order $mp$ for $p$ prime where $gcd(p,m)=1$, we consider those regular subgroups $N\leq Perm(\Gamma)$ normalized by $\lambda(\Gamma)$, the left regular representation of $\Gamma$. These subgroups are in one-to-one correspondence ... More
The Seiberg-Witten Equations on Manifolds with Boundary I: The Space of Monopoles and Their Boundary ValuesAug 11 2010Sep 08 2013In this paper, we study the Seiberg-Witten equations on a compact 3-manifold with boundary. Solutions to these equations are called monopoles. Under some simple topological assumptions, we show that the solution space of all monopoles is a Banach manifold ... More
The Prescribed Ricci Curvature Problem on Three-Dimensional Unimodular Lie GroupsJul 12 2016Let G be a three-dimensional unimodular Lie group, and let T be a left-invariant symmetric (0, 2)-tensor field on G. We provide the necessary and sufficient conditions on T for the existence of a pair (g, c) consisting of a left-invariant Riemannian metric ... More
Tidal Tails of Interacting GalaxiesOct 25 2012Oct 30 2012This paper has been withdrawn by the author. A computer simulation of two galaxies, passing in parabolic orbits, was made to show their interaction and the tidal patterns formed. The galaxies were modelled as a point masses surrounded by 5 densely packed, ... More
Hamiltonian handleslides for Heegaard Floer homologyJan 03 2008Feb 27 2008A $g$-tuple of disjoint, linearly independent circles in a Riemann surface of genus $g$ determines a `Heegaard torus' in its $g$-fold symmetric product. Changing the circles by a handleslide produces a new torus. It is proved that, for symplectic forms ... More
Stochastic Feynman Rules for Yang-Mills Theory on the PlaneJul 25 2016Oct 13 2016We analyze quantum Yang-Mills theory on $\mathbb{R}^2$ using a novel discretization method based on an algebraic analogue of stochastic calculus. Such an analogue involves working with "Gaussian" free fields whose covariance matrix is indefinite rather ... More
Quantization of the Nonlinear Sigma Model RevisitedAug 19 2014Sep 06 2016We revisit the subject of perturbatively quantizing the nonlinear sigma model in two dimensions from a rigorous, mathematical point of view. Our main contribution is to make precise the cohomological problem of eliminating potential anomalies that may ... More
Geometric Aspects of Multiagent SystemsOct 25 2002Recent advances in Multiagent Systems (MAS) and Epistemic Logic within Distributed Systems Theory, have used various combinatorial structures that model both the geometry of the systems and the Kripke model structure of models for the logic. Examining ... More
The Prescribed Ricci Curvature Problem on Three-Dimensional Unimodular Lie GroupsJul 12 2016Oct 05 2016Let G be a three-dimensional unimodular Lie group, and let T be a left-invariant symmetric (0, 2)-tensor field on G. We provide the necessary and sufficient conditions on T for the existence of a pair (g, c) consisting of a left-invariant Riemannian metric ... More
Computing area in presentations of the trivial groupJun 28 2016Nov 01 2016We give polynomial-time dynamic-programming algorithms finding the areas of words in the presentations $\langle a, b \mid a, b \rangle$ and $\langle a, b \mid a^k, b^k; \ k \in \mathbb{N} \rangle$ of the trivial group. In the first of these two cases, ... More
Extremal Problems in Bergman Spaces and an Extension of Ryabykh's TheoremJan 31 2013We study linear extremal problems in the Bergman space $A^p$ of the unit disc for $p$ an even integer. Given a functional on the dual space of $A^p$ with representing kernel $k \in A^q$, where $1/p + 1/q = 1$, we show that if the Taylor coefficients of ... More
Stable Commutator Length in Amalgamated Free ProductsOct 08 2013May 12 2014We show that stable commutator length is rational on free products of free Abelian groups amalgamated over $\mathbb{Z}^k$, a class of groups containing the fundamental groups of all torus knot complements. We consider a geometric model for these groups ... More
MF Actions and K-theoretic DynamicsApr 16 2014We study the interplay of C*-dynamics and K-theory. Notions of chain recurrence for transformations groups (X,G) and MF actions for non-commutative C*-dynamical systems (A,G) are translated into K-theoretical language, where purely algebraic conditions ... More
A new upper bound for $|ζ(1+ it)|$Oct 25 2012It is known that $|\zeta(1+ it)|\ll (\log t)^{2/3}$. This paper provides a new explicit estimate, viz.\ $|\zeta(1+ it)|\leq 3/4 \log t$, for $t\geq 3$. This gives the best upper bound on $|\zeta(1+ it)|$ for $t\leq 10^{2\cdot 10^{5}}$.
Symmetric function generalizations of graph polynomialsMar 30 2001In Chapter 2 we study the path-cycle symmetric function of a digraph, a symmetric function generalization of Chung and Graham's cover polynomial. Most of this material appears in either Advances in Math. 118 (1996), 71-98 or J. Algebraic Combin. 10 (1999), ... More
Faraday Induction and the Current Carriers in a CircuitOct 05 2014In this article, it is pointed out that Faraday induction can be treated from an untraditional, particle-based point of view. The electromagnetic fields of Faraday induction can be calculated explicitly from approximate point-charge fields derived from ... More
Runaway expansion in confined quasi-2D plasmas and vortex fluidsNov 06 2010The confined, quasi-two-dimensional guiding center plasma and a system of interacting line vortices in an ideal fluid are examples of Hamiltonian systems with infinite interaction distances. The existence of metastable states with negative specific is ... More
High-Q Optical Cavities in Hyperuniform Disordered MaterialsApr 27 2015We introduce the first designs for high-Q photonic cavities in slab architectures in hyperuniform disordered solids displaying isotropic band gaps. Despite their disordered character, hyperuniform disordered structures have the ability to tightly confine ... More
Understanding the Planck Blackbody Spectrum and Landau Diamagnetism within Classical ElectromagnetismJan 31 2016Mar 04 2016Electromagnetism is a \textit{relativistic} theory and one must exercise care in coupling this theory with \textit{nonrelativistic} classical mechanics and with \textit{nonrelativistic} classical statistical mechanics. Indeed historically, both the blackbody ... More
Self-Inductance and the Mass of Current Carriers in a CircuitAug 16 2014In this article, the self-inductance of a circular circuit is treated from an untraditional, particle-based point of view. The electromagnetic fields of Faraday induction are calculated explicitly from the point-charge fields derived from the Darwin Lagrangian ... More
Understanding Zero-Point Energy in the Context of Classical ElectromagnetismDec 25 2015Today's textbooks of electromagnetism give the particular solution to Maxwell's equations involving the integral over the charge and current sources at retarded times. However, the texts fail to emphasize the role played by the choice of the boundary ... More
Classical Zero-Point Radiation and Relativity: The Problem of Blackbody Radiation RevisitedNov 19 2015The physicists of the early 20th century were unaware of two ideas which are vital to understanding some aspects of modern physics within classical theory. The two ideas are: 1) the presence of classical electromagnetic zero-point radiation, and 2) the ... More
Predicting dust extinction from the stellar mass of a galaxyJul 07 2010We investigate how the typical dust extinction of H-alpha luminosity from a star-forming galaxy depends upon star formation rate (SFR), metallicity and stellar mass independently, using a sample of ~90,000 galaxies from Data Release 7 of the Sloan Digital ... More
On discrete features of the wave equation in singular pp-wave backgroundsJun 18 2008Jul 10 2008We analyze the wave equation in families of pp-wave geometries developing strong localized scale-invariant singularities in certain limits. For both cases of well-localized pp-waves and the so-called null-cosmologies, we observe an intriguing discrete ... More
Avoiding Contradictions in the Paradoxes, the Halting Problem, and DiagonalizationSep 26 2015Sep 29 2015The fundamental proposal in this article is that logical formulas of the form (f <-> ~f) are not contradictions, and that formulas of the form (t <-> t) are not tautologies. Such formulas, wherever they appear in mathematics, are instead reason to conclude ... More
On the Choice of Test Statistic for Conditional Moment InequalitiesOct 17 2014This paper derives asymptotic power functions for Cramer-von Mises (CvM) style tests for conditional moment inequality models in the set identified case. Combined with power results for Kolmogorov-Smirnov (KS) tests, these results can be used to choose ... More
The Copenhagen Interpretation Born AgainNov 07 2014Jan 05 2015An approach to quantum mechanics is developed which makes the Heisenberg cut between the deterministic microscopic quantum world and the partly deterministic, partly stochastic macroscopic world explicit. The microscopic system evolves according to the ... More
Instantons, finite N=2 Sp(N) theories and the AdS/CFT correspondenceAug 30 1999We examine ADHM multi-instantons in the conformal N=2 supersymmetric Sp(N) gauge theory with one anti-symmetric tensor and four fundamental hypermultiplets. We argue that the ADHM construction and measure can also be deduced from purely field theoretic ... More
Semi-classical decay of monopoles in N=2 gauge theoryNov 14 1996Dec 03 1996It is shown how monopoles and dyons decay on curves of marginal stability in the moduli space of vacua at weak coupling in pure N=2 gauge theory with arbitrary gauge group. The analysis involves a semi-classical treatment of the monopole and rests on ... More
Theory of phonon-assisted "forbidden" optical transitions in spin-gapped systemsJan 14 2004We consider the absorption of light with emission of one S(tot)=1 magnetic excitation in systems with a spin gap induced by quantum fluctuations. We argue that an electric dipole transition is allowed on the condition that a virtual phonon instantaneously ... More
Galactic Superwinds at Low and High RedshiftSep 05 2000In this contribution I summarize our current knowledge of the nature and significance of starburst-driven galactic superwinds. These flows are driven primarily by the kinetic energy supplied by supernovae. Superwinds are complex, multiphase phenomena ... More
Starbursts and the High-Redshift UniverseJan 15 1998Starbursts are important because they can serve as local analogs of the processes that were important in the origin and early evolution of galaxies and in the heating and chemical enrichment of the inter-galactic medium. They may also play an important ... More