Results for "Nathaniel Roth"

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Monte Carlo Radiation Hydrodynamics with Implicit MethodsApr 17 2014Jan 28 2015We explore the application of Monte Carlo transport methods to solving coupled radiation-hydrodynamics problems. We use a time-dependent, frequency-dependent, 3-dimensional radiation transport code, that is special relativistic and includes some detailed ... More
PSpectRe: A Pseudo-Spectral Code for (P)reheatingMay 11 2010Aug 20 2010PSpectRe is a C++ program that uses Fourier-space pseudo-spectral methods to evolve interacting scalar fields in an expanding universe. PSpectRe is optimized for the analysis of parametric resonance in the post-inflationary universe, and provides an alternative ... More
The X-ray through Optical Fluxes and Line Strengths of Tidal Disruption EventsOct 28 2015Aug 11 2016Observations of luminous flares resulting from the possible tidal disruption of stars by supermassive black holes have raised a number of puzzles. Outstanding questions include the origin of the optical and ultraviolet (UV) flux, the weakness of hydrogen ... More
The Dynamics of Ultracompact HII RegionsNov 22 2013Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiation, the molecular cloud clump that spawned it. On one side of the star, ... More
An introduction to HKR character theoryAug 06 2013The generalized character theory of Hopkins, Kuhn, and Ravenel is an important tool in the study of Morava E-theory and higher height phenomena in chromatic homotopy theory. In this paper, we provide an introduction to HKR character theory with many examples, ... More
The Complexity of the Puzzles of Final Fantasy XIII-2Mar 07 2012We analyze the computational complexity of solving the three "temporal rift" puzzles in the recent popular video game Final Fantasy XIII-2. We show that the Tile Trial puzzle is NP-hard and we provide an efficient algorithm for solving the Crystal Bonds ... More
Subgroups of p-divisible groups and centralizers in symmetric groupsMay 28 2013For cohomology theories closely related to Morava E-theory, we provide an algebro-geometric interpretation of the cohomology of groups that arise as centralizers of tuples of commuting elements inside of symmetric groups. The interpretation is given in ... More
Precise estimates for the subelliptic heat kernel on H-type groupsOct 17 2008Jun 24 2014We establish precise upper and lower bounds for the subelliptic heat kernel on nilpotent Lie groups $G$ of H-type. Specifically, we show that there exist positive constants $C_1$, $C_2$ and a polynomial correction function $Q_t$ on $G$ such that $$C_1 ... More
Precise estimates for the subelliptic heat kernel on H-type groupsOct 17 2008Dec 01 2016We establish precise upper and lower bounds for the subelliptic heat kernel on nilpotent Lie groups $G$ of H-type. Specifically, we show that there exist positive constants $C_1$, $C_2$ and a polynomial correction function $Q_t$ on $G$ such that $$C_1 ... More
Explicit constructions of quilts with seam condition coming from symplectic reductionAug 22 2018Associated to a symplectic quotient $M/\!/G$ is a Lagrangian correspondence $\Lambda_G$ from $M/\!/G$ to $M$. In this note, we construct in two examples quilts with seam condition on such a correspondence, in the case of $S^1$ acting on $\mathbb{CP}^2$ ... More
The B36/S125 "2x2" Life-Like Cellular AutomatonMar 07 2012The B36/S125 (or "2x2") cellular automaton is one that takes place on a 2D square lattice much like Conway's Game of Life. Although it exhibits high-level behaviour that is similar to Life, such as chaotic but eventually stable evolution and the existence ... More
Non-Uniqueness of Minimal SuperpermutationsMar 18 2013We examine the open problem of finding the shortest string that contains each of the n! permutations of n symbols as contiguous substrings (i.e., the shortest superpermutation on n symbols). It has been conjectured that the shortest superpermutation has ... More
Characterizing Operations Preserving Separability Measures via Linear Preserver ProblemsAug 21 2010May 31 2011We use classical results from the theory of linear preserver problems to characterize operators that send the set of pure states with Schmidt rank no greater than k back into itself, extending known results characterizing operators that send separable ... More
The Structure of Qubit Unextendible Product BasesJan 30 2014Mar 20 2014Unextendible product bases have been shown to have many important uses in quantum information theory, particularly in the qubit case. However, very little is known about their mathematical structure beyond three qubits. We present several new results ... More
The Minimum Size of Qubit Unextendible Product BasesFeb 06 2013We investigate the problem of constructing unextendible product bases in the qubit case - that is, when each local dimension equals 2. The cardinality of the smallest unextendible product basis is known in all qubit cases except when the number of parties ... More
Rank gradient and p-gradient of amalgamated free products and HNN extensionsSep 15 2013Jul 17 2014We calculate the rank gradient and p-gradient of free products, free products with amalgamation over an amenable subgroup, and HNN extensions with an amenable associated subgroup. The notion of cost is used to compute the rank gradient of amalgamated ... More
The State of Supersymmetry after Run I of the LHCSep 02 2013Jan 09 2014In these lectures I survey the state of supersymmetric extensions of the Standard Model in light of data from the first run of the LHC. After assessing pre-LHC expectations based on principles of naturalness and parsimony, I review the landscape of direct ... More
How hot are expanding universes ?Apr 17 2008Oct 16 2008A way to address the conundrum of Quantum Gravity is to illustrate the potentially fundamental interplay between quantum field theory, curved space-times physics and thermodynamics. So far, when studying moving quantum systems in the vacuum, the only ... More
$k$-involutions of $\text{SL}(n,k)$ over Fields of Characteristic 2Sep 30 2015Symmetric $k$-varieties generalize Riemannian sym\-me\-tric spaces to reductive groups defined over arbitrary fields. For most perfect fields, it is known that symmetric $k$-varieties are in one-to-one correspondence with isomorphy classes of $k$-involutions. ... More
Non-Positive Partial Transpose Subspaces Can be as Large as Any Entangled SubspaceMay 01 2013Jun 19 2013It is known that, in an $(m \otimes n)$-dimensional quantum system, the maximum dimension of a subspace that contains only entangled states is (m-1)(n-1). We show that the exact same bound is tight if we require the stronger condition that every state ... More
Norms and Cones in the Theory of Quantum EntanglementJul 05 2012There are various notions of positivity for matrices and linear matrix-valued maps that play important roles in quantum information theory. The cones of positive semidefinite matrices and completely positive linear maps, which represent quantum states ... More
Implications of SUSY Searches for Physics Beyond the Standard ModelDec 21 2015I discuss some essential features of the electroweak hierarchy problem and the ensuing motivation for weak-scale supersymmetry. Taking the hierarchy problem seriously, null results in searches for SUSY at the LHC favor specific regions of SUSY parameter ... More
Simple Models of Superconformal FlavorApr 23 2010Jul 13 2010The observed hierarchy of fermion masses and mixings may be generated by renormalization group flow if the Standard Model is coupled to a near-conformal sector at high energies. If the conformal sector is supersymmetric, these effects are rendered calculable ... More
Separability from Spectrum for Qubit-Qudit StatesSep 08 2013The separability from spectrum problem asks for a characterization of the eigenvalues of the bipartite mixed states {\rho} with the property that U^*{\rho}U is separable for all unitary matrices U. This problem has been solved when the local dimensions ... More
An eigenspace approach to isotypic projections for data on binary treesJun 24 2014The classical Fourier transform is, in essence, a way to take data and extract components (in the form of complex exponentials) which are invariant under cyclic shifts. We consider a case in which the components must instead be invariant under automorphisms ... More
Strong hypercontractivity and strong logarithmic Sobolev inequalities for log-subharmonic functions on stratified Lie groupsJun 22 2017Jun 26 2017On a stratified Lie group $G$ equipped with hypoelliptic heat kernel measure, we study the behavior of the dilation semigroup on $L^p$ spaces of log-subharmonic functions. We consider a notion of strong hypercontractivity and a strong logarithmic Sobolev ... More
The Compass Project: Charting a New Course in Physics EducationNov 20 2012Jan 11 2013This article tells the story of the founding of the Compass Project at UC Berkeley and describes its impacts. The Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences. Its goals are to improve undergraduate ... More
3-D Radiative Transfer Calculations of Radiation Feedback from Massive Black Holes: Outflow of Mass from the Dusty "Torus"Mar 31 2012Sep 10 2012Observational and theoretical arguments suggest that the momentum carried in mass outflows from AGN can reach several times L / c, corresponding to outflow rates of hundreds of solar masses per year. Radiation pressure on lines alone may not be sufficient ... More
Inequalities for Entropy, Hausdorff Dimension, and Lipschitz ConstantsJul 03 2018We construct suitable metrics for two classes of topological dynamical systems (linear maps on the torus and non-invertible expansive maps on compact spaces) in order to get a lower bound for topological entropy in terms of the resulting Hausdorff dimensions ... More
Extracting a Paradox by the RootsNov 16 2014Zeno's paradoxes are explained as being the result of inappropriate combination of discrete and continuous mathematical systems. It is proposed that the source of this confusion lies in the course of development of the number system, which was originally ... More
Gravitational Waves from Supersymmetry BreakingFeb 11 2009In theories of supersymmetry breaking, it is often the case that there is more than one metastable vacuum. First-order phase transitions among such metastable vacua may generate a stochastic background of gravitational waves, the observation of which ... More
Brown-Peterson cohomology from Morava E-theorySep 18 2015We prove that the $p$-completed Brown-Peterson spectrum is a retract of a product of Morava $E$-theory spectra. As a consequence, we generalize results of Ravenel-Wilson-Yagita and Kashiwabara from spaces to spectra and deduce that the notion of good ... More
Nonzero coefficients in restrictions and tensor products of supercharacters of $U_n(q)$Dec 09 2009The standard supercharacter theory of the finite unipotent upper-triangular matrices $U_n(q)$ gives rise to a beautiful combinatorics based on set partitions. As with the representation theory of the symmetric group, embeddings of $U_m(q)\subseteq U_n(q)$ ... More
First passage percolation and competition modelsMay 04 2010This paper is a survey of various results and techniques in first passage percolation, a random process modeling a spreading fluid on an infinite graph. The latter half of the paper focuses on the connection between first passage percolation and a certain ... More
The structure of normal lattice supercharacter theoriesOct 02 2018The character theory of finite groups has numerous basic questions that are often already quite involved: enumerating of irreducible characters, their character formulas, point-wise product decompositions, and restriction/induction between groups. A supercharacter ... More
Transchromatic generalized character mapsOct 14 2011Sep 07 2012In "Generalized Group Characters and Complex Oriented Cohomology Theories", Hopkins, Kuhn, and Ravenel develop a way to study cohomology rings of the form E^*(BG) in terms of a character map. The character map can be interpreted as a map of cohomology ... More
Effective inhomogeneous inflation: curvature inhomogeneities of the Einstein vacuumOct 21 2010Jun 22 2011We consider spatially averaged inhomogeneous universe models and argue that, already in the absence of sources, an effective scalar field arises through foliating and spatially averaging inhomogeneous geometrical curvature invariants of the Einstein vacuum. ... More
Why does the Unruh effect rely on Lorentz invariance, while Hawking radiation does not ?Feb 27 2010We show that without Lorentz invariance, the Unruh effect does not exist. We use modified dispersion relations and describe in turn: the non-thermal nature of the vacuum (defined in the preferred frame) restricted to the Rindler wedge, the loss of the ... More
Testing Split Supersymmetry with InflationMar 27 2014Split supersymmetry (SUSY) -- in which SUSY is relevant to our universe but largely inaccessible at current accelerators -- has become increasingly plausible given the absence of new physics at the LHC, the success of gauge coupling unification, and the ... More
Doubling down on naturalness with a supersymmetric twin HiggsDec 04 2013We show that naturalness of the weak scale can be comfortably reconciled with both LHC null results and observed Higgs properties provided the double protection of supersymmetry and the twin Higgs mechanism. This double protection radically alters conventional ... More
Involutions of type $G_2$ over a field of characteristic 2Nov 29 2016In this paper we give a classification of classes of involutions on an automorphism group of an octonion algebra over fields of characteristic 2, and describe the classes of their fixed point groups.
Pattern groups and a poset based Hopf monoidOct 03 2018The supercharacter theory of algebra groups gave us a representation theoretic realization of the Hopf algebra of symmetric functions in noncommuting variables. The underlying representation theoretic framework comes equipped with two canonical bases, ... More
A Geometric Perspective on First-Passage CompetitionDec 26 2012We study the macroscopic geometry of first-passage competition on the integer lattice $Z^d$, with a particular interest in describing the behavior when one species initially occupies the exterior of a cone. First-passage competition is a stochastic process ... More
Assessing Wikipedia-Based Cross-Language Retrieval ModelsJan 10 2014This work compares concept models for cross-language retrieval: First, we adapt probabilistic Latent Semantic Analysis (pLSA) for multilingual documents. Experiments with different weighting schemes show that a weighting method favoring documents of similar ... More
Pinching of the First Eigenvalue of the Laplacian and almost-Einstein Hypersurfaces of the Euclidean SpaceFeb 07 2007In this paper, we prove new pinching theorems for the first eigenvalue of the Laplacian on compact hypersurfaces of the Euclidean space. These pinching results are associated with the upper bound for the first eigenvalue in terms of higher order mean ... More
Analysis of neuronal sequences using pairwise biasesMar 09 2016Sequences of neuronal activation have long been implicated in a variety of brain functions. In particular, these sequences have been tied to memory formation and spatial navigation in the hippocampus, a region of mammalian brains. Traditionally, neuronal ... More
Comment on `Formation of a Dodecagonal Quasicrystalline Phase in a Simple Monatomic Liquid'Jun 12 1997In a recent paper M. Dzugutov, Phys. Rev. Lett. 70 2924 (1993), describes a molecular dynamics cooling simulation where he obtained a large monatomic dodecagonal quasicrystal from a melt. The structure was stabilized by a special potential [Phys. Rev. ... More
W Mass at LEP and Standard Model FitsMay 05 2006May 16 2006The W-mass measurements from LEP and the results of a global fit of the Standard Model parameters to the electroweak data are presented. Comprehensive studies of experimental systematic effects allowed a measurement of the W mass with an accuracy of better ... More
Pontryagin's maximum principle for the Loewner equation in higher dimensionsFeb 27 2014In this paper we develop a variational method for the Loewner equation in higher dimensions. As a result we obtain a version of Pontryagin's maximum principle from optimal control theory for the Loewner equation in several complex variables. Based on ... More
Measuring Generalized Preferential Attachment in Dynamic Social NetworksJul 12 2005Jul 19 2005The mechanism of preferential attachment underpins most recent social network formation models. Yet few authors attempt to check or quantify assumptions on this mechanism. We call generalized preferential attachment any kind of preference to interact ... More
Importance Truncation for Large-Scale Configuration Interaction ApproachesMar 26 2009We introduce an iterative importance truncation scheme which aims at reducing the dimension of the model space of configuration interaction approaches by an a priori selection of the physically most relevant basis states. Using an importance measure derived ... More
Differential Privacy and the Fat-Shattering Dimension of Linear QueriesApr 19 2010Jan 19 2011In this paper, we consider the task of answering linear queries under the constraint of differential privacy. This is a general and well-studied class of queries that captures other commonly studied classes, including predicate queries and histogram queries. ... More
On the stability of the Wulff shapeNov 15 2015Given a positive function F on S n satisfying an appropriate con-vexity assumption, we consider hypersurfaces for which a linear combination of some higher order anisotropic curvatures is constant. We define the varia-tional problem for which these hypersurfaces ... More
A Supersymmetric Higgs Sector with Chiral D-termsDec 11 2012Although supersymmetry remains the best candidate for solving the electroweak hierarchy problem, a supersymmetric Higgs boson near 125 GeV requires heavy scalars, highly-mixed stops, or non-minimal contributions to the Higgs potential. Extensions of the ... More
Forecasts of Cancer and Chronic Patients: Big Data Metrics of Population HealthJul 12 2013Chronic diseases and cancer account for over 75 percent of healthcare costs in the US. Increased prevention services and improved primary care are thought to decrease costs. Current models for detecting changes in the health of populations are cumbersome ... More
The Minimum Size of Unextendible Product Bases in the Bipartite Case (and Some Multipartite Cases)Jan 08 2013A long-standing open question asks for the minimum number of vectors needed to form an unextendible product basis in a given bipartite or multipartite Hilbert space. A partial solution was found by Alon and Lovasz in 2001, but since then only a few other ... More
Process tomography for unitary quantum channelsSep 03 2013Mar 28 2014We study the number of measurements required for quantum process tomography under prior information, such as a promise that the unknown channel is unitary. We introduce the notion of an interactive observable and we show that any unitary channel acting ... More
Mapping Cones are Operator SystemsFeb 10 2011Dec 15 2011We investigate the relationship between mapping cones and matrix ordered *-vector spaces (i.e., abstract operator systems). We show that to every mapping cone there is an associated operator system on the space of n-by-n complex matrices, and furthermore ... More
Compactifying String TopologyNov 15 2011We study the string topology of a closed oriented Riemannian manifold M. We describe a compact moduli space of diagrams, and show how the cellular chain complex of this space gives algebraic operations on the singular chains of the free loop space LM ... More
Exclusive Signals of an Extended Higgs SectorJul 20 2012Nov 27 2012Expectations for the magnitude of Higgs boson signals in standard Higgs search channels at the LHC relative to Standard Model (SM) expectations are investigated within the framework of various types of CP and flavor conserving two Higgs doublet models ... More
Standard Model FitsMay 12 2004The status of the electroweak precision measurements as of winter 2004 and the global test of the Standard Model are discussed. Important input data are the precision variables measured on the Z resonance at LEP and SLC and the measurements of the W mass ... More
Should We Adjust for the Test for Pre-trends in Difference-in-Difference Designs?Apr 04 2018May 02 2018The common practice in difference-in-difference (DiD) designs is to check for parallel trends prior to treatment assignment, yet typical estimation and inference does not account for the fact that this test has occurred. I analyze the properties of the ... More
On a linear functional for infinitely divisible moving average random fieldsOct 21 2018Given a low-frequency sample of the infinitely divisible moving average random field $\{ \int_{\mathbb{R}^d} f(t-x) \Lambda(dx), \ t \in \mathbb{R}^d \}$, in [1], we proposed an estimator $\widehat{uv_0}$ for the function $\mathbb{R} \ni x \mapsto u(x)v_0(x) ... More
Constant Slope Models for Finitely Generated MapsJul 14 2017We study countably monotone and Markov interval maps. We establish sufficient conditions for uniqueness of a conjugate map of constant slope. We explain how global window perturbation can be used to generate a large class of maps satisfying these conditions. ... More
An Arena for Multi-Messenger Astrophysics: Inspiral and Tidal Disruption of White Dwarfs by Massive Black HolesFeb 18 2019The tidal disruption of stars by (super-)massive black holes in galactic nuclei has been discussed in theoretical terms for about 30 years but only in the past decade have we been able to detect such events in substantial numbers. Thus, we are now starting ... More
A unified model for tidal disruption eventsMar 08 2018In the past few years wide-field optical and UV transient surveys as well as X-ray telescopes have allowed us to identify a few dozen candidate tidal disruption events (TDEs). While in theory the physical processes in TDEs are expected to be ubiquitous, ... More
A Family of Norms With Applications In Quantum Information Theory IIJun 04 2010We consider the problem of computing the family of operator norms recently introduced in arXiv:0909.3907. We develop a family of semidefinite programs that can be used to exactly compute them in small dimensions and bound them in general. Some theoretical ... More
On TD(0) with function approximation: Concentration bounds and a centered variant with exponential convergenceNov 12 2014Sep 01 2015We provide non-asymptotic bounds for the well-known temporal difference learning algorithm TD(0) with linear function approximators. These include high-probability bounds as well as bounds in expectation. Our analysis suggests that a step-size inversely ... More
Practicality of magnetic compression for plasma density controlJan 26 2016Plasma densification through magnetic compression has been suggested for time-resolved control of the wave properties in plasma-based accelerators. Using particle in cell simulations with real mass ratio, the practicality of large magnetic compression ... More
A transchromatic proof of Strickland's theoremApr 02 2014In "Morava E-theory of symmetric groups", Strickland proved that the Morava E-theory of the symmetric group has an algebro-geometric interpretation after taking the quotient by a certain transfer ideal. This result has influenced most of the work on power ... More
Reducing parametric backscattering by polarization rotationJun 27 2016Sep 20 2016When a laser passes through underdense plasmas, Raman and Brillouin Backscattering can reflect a substantial portion of the incident laser energy. This is a major loss mechanism, for example, in employing lasers in inertial confinement fusion. However, ... More
X-ray Hardness Variations as an Internal/External Shock DiagnosticFeb 23 2007Jun 22 2007The early, highly time-variable X-ray emission immediately following GRBs exhibits strong spectral variations that are unlike the temporally smoother emission which dominates after $t\sim 10^3$ s. The ratio of hard channel (1.3-10.0 keV) to soft channel ... More
Building a Better mSUGRA: WIMP Dark Matter Without Flavor ViolationJun 10 2009The appearance of a natural dark matter candidate, the neutralino, is among the principal successes of minimal supergravity (mSUGRA) and its descendents. In lieu of a suitable ultraviolet completion, however, theories of gravity-mediated supersymmetry ... More
On the Phenomenology of Strongly Coupled Hidden SectorsMay 25 2009In models of supersymmetry (SUSY) breaking and mediation, strongly coupled SUSY-breaking sectors can play a significant role in determining the low-energy spectrum of the model. For example, strong dynamics may provide a natural solution to both the SUSY ... More
Instability in Predictive MatterNov 29 2016We study the dynamics of a swarm in which agents have full knowledge of the physical laws governing the system they live in. Agents aim to maximize their resource uptake by solving these laws to predict the future of their environment and other agents. ... More
On the characteristic map of finite unitary groupsNov 09 2005In his classic book on symmetric functions, Macdonald describes a remarkable result by Green relating the character theory of the finite general linear group to transition matrices between bases of symmetric functions. This connection allows us to analyze ... More
Values of characters sums for finite unitary groupsSep 18 2007A known result for the finite general linear group $\GL(n,\FF_q)$ and for the finite unitary group $\U(n,\FF_{q^2})$ posits that the sum of the irreducible character degrees is equal to the number of symmetric matrices in the group. Fulman and Guralnick ... More
Gelfand-Graev characters of the finite unitary groupsNov 01 2006Gelfand-Graev characters and their degenerate counterparts have an important role in the representation theory of finite groups of Lie type. Using a characteristic map to translate the character theory of the finite unitary groups into the language of ... More
Quantum factorization of 56153 with only 4 qubitsNov 25 2014Nov 27 2014The largest number factored on a quantum device reported until now was 143. That quantum computation, which used only 4 qubits at 300K, actually also factored much larger numbers such as 3599, 11663, and 56153, without the awareness of the authors of ... More
Compressing turbulence and sudden viscous dissipation with compression-dependent ionization stateMay 10 2016Oct 27 2016Turbulent plasma flow, amplified by rapid 3D compression, can be suddenly dissipated under continuing compression. This effect relies on the sensitivity of the plasma viscosity to the temperature, $\mu \sim T^{5/2}$. The plasma viscosity is also sensitive ... More
Geometry of Centroaffine Surfaces in $\mathbb{R}^5$Aug 18 2014Jan 06 2015We use Cartan's method of moving frames to compute a complete set of local invariants for nondegenerate, 2-dimensional centroaffine surfaces in $\mathbb{R}^5 \setminus \{0\}$ with nondegenerate centroaffine metric. We then give a complete classification ... More
Duality of Entanglement NormsApr 08 2013We consider four norms on tensor product spaces that have appeared in quantum information theory and demonstrate duality relationships between them. We show that the product numerical radius is dual to the robustness of entanglement, and we similarly ... More
Generalized Multiplicative Domains and Quantum Error CorrectionApr 28 2010Given a completely positive map, we introduce a set of algebras that we refer to as its generalized multiplicative domains. These algebras are generalizations of the traditional multiplicative domain of a completely positive map and we derive a characterization ... More
Rational cohomology from supersymmetric field theoriesMar 06 2014We show that Sullivan's model of rational differential forms on a simplicial set $X$ may be interpreted as a (kind of) $0|1$-dimensional supersymmetric quantum field theory over $X$, and, as a consequence, concordance classes of such theories represent ... More
Quantum Gate Fidelity in Terms of Choi MatricesFeb 04 2011Nov 07 2011We provide new results for computing and comparing the quantum gate fidelity of quantum channels via their Choi matrices. We extend recent work that showed there exist non-dual pairs of quantum channels with equal gate fidelity by providing an explicit ... More
A Family of Norms With Applications In Quantum Information TheorySep 22 2009Aug 20 2010We consider a family of vector and operator norms defined by the Schmidt decomposition theorem for quantum states. We use these norms to tackle two fundamental problems in quantum information theory: the classification problem for k-positive linear maps ... More
Axion-Assisted Electroweak BaryogenesisJun 30 2010We consider a hidden-valley gauge sector, G, with strong coupling scale Lambda~TeV and CP-violating topological parameter, theta, as well as a new axion degree of freedom which adjusts theta to near zero in the current universe. If the G-sector couples ... More
Propagation dynamics of vortices in Helico-Conical optical beamsMay 29 2015Aug 13 2015We present the dynamics of optical vortices (OVs) that came from the propagation of helico-conical optical beam. This dynamics is investigated numerically by tracking the OVs at several distances using rigorous scalar diffraction theory. To ensure that ... More
Stellar Velocity Dispersion in Mergers: The Effects of Dust and Star FormationOct 09 2016We investigate the effects of stellar evolution and dust on measurements of stellar velocity dispersion in mergers of disk galaxies. $N$-body simulations and radiative transfer analysis software are used to obtain mass-weighted and flux-weighted measurements ... More
Widder's representation theorem for symmetric local Dirichlet spacesApr 09 2012Feb 14 2013In classical PDE theory, Widder's theorem gives a representation for nonnegative solutions of the heat equation on $\mathbb{R}^n$. We show that an analogous theorem holds for local weak solutions of the canonical "heat equation" on a symmetric local Dirichlet ... More
Algorithms and error bounds for noisy phase retrieval with low-redundancy framesDec 20 2014The main objective of this paper is to find algorithms accompanied by explicit error bounds for phase retrieval from noisy magnitudes of frame coefficients when the underlying frame has a low redundancy. We achieve these goals with frames consisting of ... More
Fair Measures for Countable-to-one MapsOct 16 2018In this paper we generalize the recently introduced concept of fair measure (M. Misiurewicz and A. Rodrigues, Counting preimages. Ergod. Th. & Dynam. Sys. 38 (2018), no. 5, 1837 -- 1856). We study transitive countable state Markov shift maps and extend ... More
Sympathetically cooled molecular ions: from principles to first applicationsDec 05 2008We review the current status of the field of sympathetically cooled molecular ions, i.e. the method used for cooling the translational degrees of freedom, the techniques applied for detection and analysis of the cold trapped ion ensembles produced as ... More
QED corrections to the evolution of parton distributionsMar 18 2004We study the systematic inclusion of QED corrections in the evolution of parton distributions. O(alpha) corrections modify the evolution equation for parton distributions. They introduce additional parton distributions, like the photon distribution in ... More
Binding Social and Cultural Networks: A ModelSep 10 2003Nov 05 2003Until now, most studies carried onto social or semantic networks have considered each of these networks independently. Our goal here is to bring a formal frame for studying both networks empirically as well as to point out stylized facts that would explain ... More
No Semiconjugacy to a Map of Constant SlopeMar 11 2014We study countably piecewise continuous, piecewise monotone interval maps. We establish a necessary and sufficient criterion for the existence of a nondecreasing semiconjugacy to a map of constant slope in terms of the existence of an eigenvector of an ... More
Term Definitions Help Hypernymy DetectionJun 12 2018Existing methods of hypernymy detection mainly rely on statistics over a big corpus, either mining some co-occurring patterns like "animals such as cats" or embedding words of interest into context-aware vectors. These approaches are therefore limited ... More
Critical points of inner functions, nonlinear partial differential equations, and an extension of Liouville's theoremAug 29 2007We establish an extension of Liouville's classical representation theorem for solutions of the partial differential equation $\Delta u=4 e^{2u}$ and combine this result with methods from nonlinear elliptic PDE to construct holomorphic maps with prescribed ... More
Complex and Lagrangian surfaces of the complex projective plane via Kählerian Killing Spin$^c$ spinorsJun 20 2016Feb 07 2017The complex projective space $\mathbb C P^2$ of complex dimension $2$ has a Spin$^c$ structure carrying K\"ahlerian Killing spinors. The restriction of one of these K\"ahlerian Killing spinors to a surface $M^2$ characterizes the isometric immersion of ... More
Support points and the Bieberbach conjecture in higher dimensionMar 04 2016We describe some open questions related to support points in the class $S^0$ and introduce some useful techniques toward a higher dimensional Bieberbach conjecture.