Results for "Simeon Reich"

total 629took 0.13s
Fixed points of polarity type operatorsAug 30 2017Apr 08 2019A well-known result says that the Euclidean unit ball is the unique fixed point of the polarity operator. This result implies that if, in $\mathbb{R}^n$, the unit ball of some norm is equal to the unit ball of the dual norm, then the norm must be Euclidean. ... More
Regular Sequences of Quasi-Nonexpansive Operators and Their ApplicationsOct 02 2017Feb 10 2018In this paper we present a systematic study of regular sequences of quasi-nonexpansive operators in Hilbert space. We are interested, in particular, in weakly, boundedly and linearly regular sequences of operators. We show that the type of the regularity ... More
Weak, Strong and Linear Convergence of a Double-Layer Fixed Point AlgorithmMar 28 2017In this article we consider a consistent convex feasibility problem in a real Hilbert space defined by a finite family of sets $C_i$. We are interested, in particular, in the case where for each $i$, $C_i=Fix (U_i)=\{z\in \mathcal H\mid p_i(z)=0\}$, $U_i\colon\mathcal ... More
Outer Approximation Methods for Solving Variational Inequalities Defined over the Solution Set of a Split Convex Feasibility ProblemAug 20 2019We study variational inequalities which are governed by a strongly monotone and Lipschitz continuous operator $F$ over a closed and convex set $S$. We assume that $S=C\cap A^{-1}(Q)$ is the nonempty solution set of a (multiple-set) split convex feasibility ... More
Linear Convergence Rates for Extrapolated Fixed Point AlgorithmsMay 10 2018We establish linear convergence rates for a certain class of extrapolated fixed point algorithms which are based on dynamic string-averaging methods in a real Hilbert space. This applies, in particular, to the extrapolated simultaneous and cyclic cutter ... More
Fixed points of polarity type operatorsAug 30 2017Aug 05 2018A well-known result says that the Euclidean unit ball is the unique fixed point of the polarity operator. This result implies that if, in $\mathbb{R}^n$, the unit ball of some norm is equal to the unit ball of the dual norm, then the norm must be Euclidean. ... More
Generic Convergence of Sequences of Successive Approximations in Banach SpacesMar 26 2019We study the generic behavior of the method of successive approximations for set-valued mappings in Banach spaces. We consider, in particular, the case of those set-valued mappings which are defined by pairs of nonexpansive mappings and give a positive ... More
A note on alternating projections in Hilbert spaceFeb 23 2017We provide a direct proof of a result regarding the asymptotic behavior of alternating nearest point projections onto two closed and convex sets in a Hilbert space. Our arguments are based on nonexpansive mapping theory.
Optimal pricing for optimal transportMay 19 2014Suppose that $c(x,y)$ is the cost of transporting a unit of mass from $x\in X$ to $y\in Y$ and suppose that a mass distribution $\mu$ on $X$ is transported optimally (so that the total cost of transportation is minimal) to the mass distribution $\nu$ ... More
Solutions to the inexact resolvent inclusion problem with applications to nonlinear analysis and optimizationOct 02 2016The exact resolvent inclusion problem has various applications in nonlinear analysis and optimization theory, such as devising (proximal) algorithmic schemes aiming at minimizing convex functions and finding zeros of nonlinear operators. The inexact version ... More
Abstract convex optimal antiderivativesJan 27 2014Having studied families of antiderivatives and their envelopes in the setting of classical convex analysis, we now extend and apply these notions and results in settings of abstract convex analysis. Given partial data regarding a c-subdifferential, we ... More
Zone and double zone diagrams in abstract spacesAug 19 2007Jul 25 2011A zone diagram is a relatively new concept which was first defined and studied by T. Asano, J. Matousek and T. Tokuyama. It can be interpreted as a state of equilibrium between several mutually hostile kingdoms. Formally, it is a fixed point of a certain ... More
The Optimal Error Bound for the Method of Simultaneous ProjectionsApr 02 2017Sep 14 2017In this paper we find the optimal error bound (smallest possible estimate, independent of the starting point) for the linear convergence rate of the simultaneous projection method applied to closed linear subspaces in a real Hilbert space. We achieve ... More
The asymptotic behavior of a class of nonlinear semigroups in Hadamard spacesMay 26 2014Jul 24 2014We study a nonlinear semigroup associated to a nonexpansive mapping on a Hadamard space and establish its weak convergence to a fixed point. A discrete-time counterpart of such a semigroup, the proximal point algorithm, turns out to have the same asymptotic ... More
Solutions to inexact resolvent inclusion problems with applications to nonlinear analysis and optimizationOct 02 2016Aug 22 2017Many problems in nonlinear analysis and optimization, among them variational inequalities and minimization of convex functions, can be reduced to finding zeros (namely, roots) of set-valued operators. Hence numerous algorithms have been devised in order ... More
A Julia--Carathéodory theorem for hyperbolically monotone mappings in the Hilbert ballAug 04 2006We establish a Julia--Carath\'eodory theorem and a boundary Schwarz--Wolff lemma for hyperbolically monotone mappings in the open unit ball of a complex Hilbert space
Fixed points of Legendre-Fenchel type transformsJul 25 2017Apr 30 2018A recent result characterizes the fully order reversing operators acting on the class of lower semicontinuous proper convex functions in a real Banach space as certain linear deformations of the Legendre-Fenchel transform. Motivated by the Hilbert space ... More
Outer Approximation Methods for Solving Variational Inequalities in Hilbert SpaceFeb 02 2017In this paper we study variational inequalities in a real Hilbert space, which are governed by a strongly monotone and Lipschitz continuous operator $F$ over a closed and convex set $C$. We assume that the set $C$ can be outerly approximated by the fixed ... More
BISTA: a Bregmanian proximal gradient method without the global Lipschitz continuity assumptionApr 19 2018Dec 13 2018The problem of minimization of the sum of two convex functions has various theoretical and real-world applications. One of the popular methods for solving this problem is the proximal gradient method (proximal forward-backward algorithm). A very common ... More
A telescoping Bregmanian proximal gradient method without the global Lipschitz continuity assumptionApr 19 2018Feb 24 2019The problem of minimization of the sum of two convex functions has various theoretical and real-world applications. One of the popular methods for solving this problem is the proximal gradient method (proximal forward-backward algorithm). A very common ... More
Zone diagrams in compact subsets of uniformly convex normed spacesFeb 18 2010Jul 25 2011A zone diagram is a relatively new concept which has emerged in computational geometry and is related to Voronoi diagrams. Formally, it is a fixed point of a certain mapping, and neither its uniqueness nor its existence are obvious in advance. It has ... More
Stability of the optimal values under small perturbations of the constraint setFeb 06 2019Aug 07 2019This paper discusses a general and useful stability principle which, roughly speaking, says that given a uniformly continuous function defined on an arbitrary metric space, if we slightly change the constraint set over which the optimal (extreme) values ... More
A telescoping Bregmanian proximal gradient method without the global Lipschitz continuity assumptionApr 19 2018Mar 19 2019The problem of minimization of the sum of two convex functions has various theoretical and real-world applications. One of the popular methods for solving this problem is the proximal gradient method (proximal forward-backward algorithm). A very common ... More
Re-examination of Bregman functions and new properties of their divergencesMar 01 2018Apr 08 2019The Bregman divergence (Bregman distance, Bregman measure of distance) is a certain useful substitute for a distance, obtained from a well-chosen function (the "Bregman function"). Bregman functions and divergences have been extensively investigated during ... More
Porosity Results for Sets of Strict Contractions on Geodesic Metric SpacesFeb 08 2016Apr 18 2016We consider a large class of geodesic metric spaces, including Banach spaces, hyperbolic spaces and geodesic $\mathrm{CAT}(\kappa)$-spaces, and investigate the space of nonexpansive mappings on either a convex or a star-shaped subset in these settings. ... More
A von Neumann Alternating Method for Finding Common Solutions to Variational InequalitiesFeb 03 2012Modifying von Neumann's alternating projections algorithm, we obtain an alternating method for solving the recently introduced Common Solutions to Variational Inequalities Problem (CSVIP). For simplicity, we mainly confine our attention to the two-set ... More
Finitely Convergent Deterministic and Stochastic Methods for Solving Convex Feasibility ProblemsMay 14 2019We propose finitely convergent methods for solving convex feasibility problems defined over a possibly infinite pool of constraints. Following other works in this area, we assume that the interior of the solution set is nonempty and that certain overrelaxation ... More
Convergence Properties of Dynamic String Averaging Projection Methods in the Presence of PerturbationsMar 22 2017Assuming that the absence of perturbations guarantees weak or strong convergence to a common fixed point, we study the behavior of perturbed products of an infinite family of nonexpansive operators. Our main result indicates that the convergence rate ... More
Porosity Results for Sets of Strict Contractions on Geodesic Metric SpacesFeb 08 2016Feb 12 2017We consider a large class of geodesic metric spaces, including Banach spaces, hyperbolic spaces and geodesic $\mathrm{CAT}(\kappa)$-spaces, and investigate the space of nonexpansive mappings on either a convex or a star-shaped subset in these settings. ... More
Fixed points of Legendre-Fenchel type transformsJul 25 2017Apr 08 2019A recent result characterizes the fully order reversing operators acting on the class of lower semicontinuous proper convex functions in a real Banach space as certain linear deformations of the Legendre-Fenchel transform. Motivated by the Hilbert space ... More
Re-examination of Bregman functions and new properties of their divergencesMar 01 2018Nov 20 2018The Bregman divergence (Bregman distance, Bregman measure of distance) is a certain useful substitute for a distance, obtained from a well-chosen function (the "Bregman function"). Bregman functions and divergences have been extensively investigated during ... More
Algorithms for the Split Variational Inequality ProblemSep 20 2010Aug 10 2011We propose a prototypical Split Inverse Problem (SIP) and a new variational problem, called the Split Variational Inequality Problem (SVIP), which is a SIP. It entails finding a solution of one inverse problem (e.g., a Variational Inequality Problem (VIP)), ... More
Stability of the optimal values under small perturbations of the constraint setFeb 06 2019This paper presents a general and useful stability principle which, roughly speaking, says that given a uniformly continuous function defined on an arbitrary metric space, if we slightly change the constraint set over which the optimal (extreme) values ... More
Two results in metric fixed point theoryMar 05 2018We establish two fixed point theorems for certain mappings of contractive type. The first result is concerned with the case where such mappings take a nonempty, closed subset of a complete metric space $X$ into $X$, and the second with an application ... More
Rigidity, boundary interpolation and reproducing kernelsSep 16 2007We use reproducing kernel methods to study various rigidity problems. The methods and setting allow us to also consider the non-positive case.
Weak, Strong and Linear Convergence of the CQ-Method Via the Regularity of Landweber OperatorsDec 18 2018We consider the split convex feasibility problem in a fixed point setting. Motivated by the well-known CQ-method of Byrne (2002), we define an abstract andweber transform which applies to more general operators than the metric projection. We call the ... More
A Universal Inequality for CFT and Quantum GravityFeb 17 2009Mar 30 2011We prove that every unitary two-dimensional conformal field theory (with no extended chiral algebra, and with central charges c_L, c_R > 1) contains a primary operator with dimension Delta_1 that satisfies 0 < Delta_1 < (c_L + c_R)/12 + 0.473695. Translated ... More
New Type II String Theories with Sixteen SuperchargesDec 05 2005Dec 12 2005We present two new backgrounds of type IIA string theory preserving 16 supercharges. One is a Wilson line for (-1) to the left-moving spacetime fermion number, and the other is an orbifold by a reflection of four coordinates, along with the action of ... More
ParaSasakian manifolds with a constant paraholomorphic section curvatureDec 09 2008May 31 2009In this paper paraSasakian manifolds with a constant paraholomorphic section curvature are considered.
Author Identifiers in Scholarly RepositoriesMar 06 2010Bibliometric and usage-based analyses and tools highlight the value of information about scholarship contained within the network of authors, articles and usage data. Less progress has been made on populating and using the author side of this network ... More
On sets defining few ordinary planesJun 03 2016Jun 21 2017Let $S$ be a set of $n$ points in real three-dimensional space, no three collinear and not all co-planar. We prove that if the number of planes incident with exactly three points of $S$ is less than $Kn^2$ for some $K=o(n^{\frac{1}{7}})$ then, for $n$ ... More
On sets defining few ordinary planesJun 03 2016Jul 20 2016Let $S$ be a set of $n$ points in real $3$-space. We prove that if the number of planes incident with exactly three points of $S$ is less than $Kn^2$ for some $K=o(n^{\frac{1}{6}})$ then, for $n$ sufficiently large, all but at most $O(K)$ points of $S$ ... More
Minimally Parametric Constraints on the Primordial Power Spectrum from Lyman-alphaMay 21 2010Current analyses of the Lyman-alpha forest assume that the primordial power spectrum of density perturbations obeys a simple power law, a strong theoretical assumption which should be tested. Employing a large suite of numerical simulations which drop ... More
On the geometry of trans-para-Sasakian manifoldsDec 05 2018Dec 30 2018In this paper, we introduce the trans-para-Sasakian manifolds and we study their geometry. These manifolds are an analogue of the trans-Sasakian manifolds in the Riemannian geometry. We shall investigate many curvature properties of these manifolds and ... More
Some constructions of quantum MDS codesJul 09 2019Jul 18 2019We construct quantum MDS codes for quantum systems of dimension $q$ of length $q^2+1$ and minimum distance $d$ for all $d \leqslant q+1$, $d \neq q$. These codes are shown to exist by proving that there are classical generalised Reed-Solomon codes which ... More
Ribbon invariants IAug 13 2017Oct 09 2018A non-negative integer invariant, estimating from below the number of geometrically different critical points of a smooth function $f$ defined in the 2-disk, $f:\mathbb{B}^{2}\rightarrow\mathbb{R}$, is considered. (We denote it by "$\gamma$".) It depends ... More
Open Archives Initiative protocol development and implementation at arXivJan 26 2001I outline the involvement of the Los Alamos e-print archive (arXiv) within the Open Archives Initiative (OAI) and describe the implementation of the data provider side of the OAI protocol v1.0. I highlight the ways in which we map the existing structure ... More
NMR Spectroscopy and the Crystal-Field Interaction in Holmium TrifluorideMay 16 2000The work to be described falls into three parts: (1) The computer-controlled CW spectrometer was designed to supplement the Manchester pulsed microwave spectrometer in situations where rapid nuclear relaxation makes spin-echo spectroscopy difficult. Its ... More
Measuring and calibrating Galactic synchrotron emissionDec 22 2008Our position inside the Galaxy requires all-sky surveys to reveal its large-scale properties. The zero-level calibration of all-sky surveys differs from standard 'relative' measurements, where a source is measured in respect to its surroundings. All-sky ... More
Linearization models for parabolic dynamical systems via Abel's functional equationJul 15 2009We study linearization models for continuous one-parameter semigroups of parabolic type. In particular, we introduce new limit schemes to obtain solutions of Abel's functional equation and to study asymptotic behavior of such semigroups. The crucial point ... More
Some constructions of quantum MDS codesJul 09 2019We construct quantum MDS codes for quantum systems of dimension $q$ of length $q^2+1$ and minimum distance $d$ for all $d \leqslant q+1$, $d \neq q$. These codes are shown to exist by proving that there are classical generalised Reed-Solomon codes which ... More
Canonical connections on paracontact manifoldsJul 12 2007Aug 24 2007The canonical paracontact connection is defined and it is shown that its torsion is the obstruction the paracontact manifold to be paraSasakian. A $\mathcal{D}$-homothetic transformation is determined as a special gauge transformation. The $\eta$-Einstein ... More
Geometry of Paraquaternionic Kahler manifolds with torsionNov 25 2005We study the geometry of PQKT-connections. We find conditions to the existence of a PQKT-connection and prove that if it exists it is unique. We show that PQKT geometry persist in a conformal class of metrics.
The OAI Data-Provider Registration and Validation ServiceJun 03 2005I present a summary of recent use of the Open Archives Initiative (OAI) registration and validation services for data-providers. The registration service has seen a steady stream of registrations since its launch in 2002, and there are now over 220 registered ... More
Exposing and harvesting metadata using the OAI metadata harvesting protocol: A tutorialJun 28 2001In this article I outline the ideas behind the Open Archives Initiative metadata harvesting protocol (OAIMH), and attempt to clarify some common misconceptions. I then consider how the OAIMH protocol can be used to expose and harvest metadata. Perl code ... More
Eprints and the Open Archives InitiativeJul 04 2003The Open Archives Initiative (OAI) was created as a practical way to promote interoperability between eprint repositories. Although the scope of the OAI has been broadened, eprint repositories still represent a significant fraction of OAI data providers. ... More
Commuting semigroups of holomorphic mappingsSep 30 2006Let $S_{1}=\left\{F_t\right\}_{t\geq 0}$ and $S_{2}=\left\{G_t\right\}_{t\geq 0}$ be two continuous semigroups of holomorphic self-mappings of the unit disk $\Delta=\{z:|z|<1\}$ generated by $f$ and $g$, respectively. We present conditions on the behavior ... More
Growth Estimates for the Numerical Range of Holomorphic Mappings and ApplicationsFeb 27 2015Nov 11 2015The numerical range of holomorphic mappings arises in many aspects of nonlinear analysis, finite and infinite dimensional holomorphy, and complex dynamical systems. In particular, this notion plays a crucial role in establishing exponential and product ... More
An algorithm for solving the variational inequality problem over the fixed point set of a quasi-nonexpansive operator in Euclidean spaceApr 02 2013This paper is concerned with the variational inequality problem (VIP) over the fixed point set of a quasi-nonexpansive operator. We propose, in particular, an algorithm which entails, at each step, projecting onto a suitably chosen half-space, and prove ... More
A rigidity theorem for holomorphic generators on the Hilbert ballAug 21 2007We present a rigidity property of holomorphic generators on the open unit ball $\mathbb{B}$ of a Hilbert space $H$. Namely, if $f\in\Hol (\mathbb{B},H)$ is the generator of a one-parameter continuous semigroup ${F_t}_{t\geq 0}$ on $\mathbb{B}$ such that ... More
The Split Common Null Point ProblemAug 30 2011Apr 16 2012We introduce and study the Split Common Null Point Problem (SCNPP) for set-valued maximal monotone mappings in Hilbert spaces. This problem generalizes our Split Variational Inequality Problem (SVIP) [Y. Censor, A. Gibali and S. Reich, Algorithms for ... More
The Bolzano-Poincaré-Miranda theorem in infinite dimensional Banach spacesJul 03 2018We study the existence of zeroes of mappings defined in Banach spaces. We obtain, in particular, an extension of the well-known Bolzano-Poincar\'e-Miranda theorem to infinite dimensional Banach spaces. We also establish a result regarding the existence ... More
Radio Observations of Supernova RemnantsAug 28 2002Supernovae release an enormous amount of energy into the interstellar medium. Their remnants can observationally be traced up to several ten-thousand years. So far more than 230 Galactic supernova remnants (SNRs) have been identified in the radio range. ... More
L^2-Betti numbers, isomorphism conjectures and noncommutative localizationMar 07 2003In this paper we discuss how the question about the rationality of L^2-Betti numbers is related to the Isomorphism Conjecture in algebraic K-theory and why in this context noncommutative localization appears as an important tool.
Galactic polarization surveysMar 17 2006Following the detection of polarized diffuse Galactic emission in 1962 a number of surveys were undertaken at low frequencies in the following years resulting in important insights on the local magnetic field, polarization of the giant radio loops and ... More
G0.087-0.087, a highly polarized flat spectrum filament near the Galactic Centre ArcFeb 18 200332 GHz observations with the Effelsberg 100-m telescope revealed a highly polarized Galactic Centre filament: G0.087-0.087, running parallel to the well-known Arc structure. It has a similar flat spectrum, but it is an order of magnitude weaker. G0.087-0.087 ... More
Processes, Roles and Their InteractionsFeb 21 2012Taking an interaction network oriented perspective in informatics raises the challenge to describe deterministic finite systems which take part in networks of nondeterministic interactions. The traditional approach to describe processes as stepwise executable ... More
Data Assimilation: The Schrödinger PerspectiveJul 22 2018Apr 10 2019Data assimilation addresses the general problem of how to combine model-based predictions with partial and noisy observations of the process in an optimal manner. This survey focuses on sequential data assimilation techniques using probabilistic particle-based ... More
DataDec 23 2017Jun 07 2018The contribution of this article is a data concept that is essentially based on the two concepts of information and computable functionality. In short, data is viewed as typed information. A data type is defined as a pair of a set of distinguishable characters ... More
A Gaussian mixture ensemble transform filterFeb 15 2011Jul 06 2011We generalize the popular ensemble Kalman filter to an ensemble transform filter where the prior distribution can take the form of a Gaussian mixture or a Gaussian kernel density estimator. The design of the filter is based on a continuous formulation ... More
Data Assimilation: The Schrödinger PerspectiveJul 22 2018May 01 2019Data assimilation addresses the general problem of how to combine model-based predictions with partial and noisy observations of the process in an optimal manner. This survey focuses on sequential data assimilation techniques using probabilistic particle-based ... More
Composition, Cooperation, and Coordination of Computational SystemsFeb 23 2016A system model is developed where the criterion to partition the world into a system and a rest is based on the functional relation between its states. This approach implies that the gestalt of systems becomes very dynamic. Especially interactions between ... More
A Non-analytic Superposition Result on Gevrey-modulation SpacesNov 12 2014After defining classical weighted modulation spaces we show some basic properties. In this work we additionally choose an approach in terms of the frequency-uniform decomposition and a discussion on the weights of modulation spaces leads to a definition ... More
Superposition in Modulation Spaces with Ultradifferentiable WeightsMar 29 2016In the theory of nonlinear partial differential equations we need to explain superposition operators. For modulation spaces equipped with particular ultradifferentiable weights this was done in \cite{rrs}. In this paper we introduce a class of general ... More
Determinants of elliptic pseudo-differential operatorsApr 07 1994Determinants of invertible pseudo-differential operators (PDOs) close to positive self-adjoint ones are defined throughthe zeta-function regularization. We define a multiplicative anomaly as the ratio $\det(AB)/(\det(A)\det(B))$ considered as a functionon ... More
Boundary Operators in Effective String TheorySep 06 2016Various universal features of relativistic rotating strings depend on the organization of allowed local operators on the worldsheet. In this paper, we study the set of Neumann boundary operators in effective string theory, which are relevant for the controlled ... More
Dynamical Cobordisms in General Relativity and String TheorySep 16 2010Nov 06 2010We describe a class of time-dependent solutions in string- or M-theory that are exact with respect to alpha-prime and curvature corrections and interpolate in physical space between regions in which the low energy physics is well-approximated by different ... More
Linear sigma model toolshed for D-brane physicsApr 10 2001Sep 21 2001Building on earlier work, we construct linear sigma models for strings on curved spaces in the presence of branes. Our models include an extremely general class of brane-worldvolume gauge field configurations. We explain in an accessible manner the mathematical ... More
D(NA)-BranesApr 02 2001Apr 04 2001We engineer a configuration of branes in type IIB string theory whose mechanical structure is that of a DNA molecule. We obtain it by considering a T-dual description of the quantum Hall soliton. Using a probe analysis, we investigate the dynamics of ... More
On sets of points with few odd secantsNov 29 2017We prove that, for $q$ odd and large enough, a set of $q+2$ points in the projective plane over the field with $q$ elements has at least $2q-c$ odd secants, where $c$ is a constant and an odd secant is a line incident with an odd number of points of the ... More
Non-existence of flat paracontact metric structures in dimension greater than or equal to fiveOct 30 2009An example of a three dimensional flat paracontact metric manifold with respect to Levi-Civita connection is constructed. It is shown that no such manifold exists for odd dimensions greater than or equal to five.
Dynamics of wetting explored with inkjet printingNov 11 2016Feb 20 2017An inkjet printer head, which is capable of depositing liquid droplets with a resolution of $22$ picoliters and high repeatability, is employed to investigate the wetting dynamics of drops printed on a horizontal plane as well as on a granular monolayer. ... More
A generalisation of Sylvester's problem to higher dimensionsAug 10 2016In this article we consider $S$ to be a set of points in $d$-space with the property that any $d$ points of $S$ span a hyperplane and not all the points of $S$ are contained in a hyperplane. The aim of this article is to introduce the function $e_d(n)$, ... More
Supercritical N = 2 string theorySep 13 2007Sep 16 2007The N=2 string is examined in dimensions above the critical dimension (D=4) in a linear dilaton background. We demonstrate that string states in this background propagate in a single physical time dimension, as opposed to two such dimensions present when ... More
Dynamical Dimension Change in Supercritical String TheorySep 07 2004Sep 07 2004We study tree-level solutions to heterotic string theory in which the number of spacetime dimensions 10+n changes dynamically due to closed string tachyon condensation. Taking the large-n limit, we compute the amount by which the dilaton gradient changes ... More
Realizing the Quantum Hall System in String TheoryJul 23 2001Jul 31 2001In a recent paper Bernevig, Brodie, Susskind and Toumbas constructed a brane realization of the Quantum Hall fluid. Since then it has been realized that the Quantum Hall system is very closely related to non--commutative Chern Simons theory and this suggests ... More
String Theory of the Regge InterceptDec 04 2013Using the Polchinski-Strominger effective string theory in covariant gauge, we compute the mass of a rotating string in D dimensions with large angular momenta J, in one or two planes, in fixed ratio, up to and including first subleading order in the ... More
A stable vacuum of the tachyonic E8 stringOct 09 2007Apr 29 2008We consider tachyon condensation in unstable ten-dimensional heterotic string theory with gauge group E8. In the background of a lightlike linear dilaton rolling to weak coupling, we find an exact solution in which the theory decays to a stable ground ... More
Forbidden subgraphs in the norm graphFeb 05 2015We show that the norm graph constructed in [J. Koll\'{a}r, L. R\'{o}nyai and T. Szab\'o, Norm-graphs and bipartite Tur\'{a}n numbers, Combinatorica, 16 (1996) 399--406] with $n$ vertices about $\frac{1}{2}n^{2-1/t}$ edges, which contains no copy of $K_{t,(t-1)!+1}$, ... More
Bound-state asymptotic estimates for window-coupled Dirichlet strips and layersSep 25 1997We consider the discrete spectrum of the Dirichlet Laplacian on a manifold consisting of two adjacent parallel strips or planar layers coupled by a finite number N of windows in the common boundary. If the windows are small enough, there is just one isolated ... More
Giant Lyman-Alpha Nebulae in the Illustris SimulationMay 11 2016Several `giant' Lyman-$\alpha$ (Ly$\alpha$) nebulae with extent $\gtrsim 300\,$kpc and observed Ly$\alpha$ luminosity of $\gtrsim 10^{44}\,{\rm erg}\,{\rm s}^{-1}\,{\rm cm}^{-2}\,{\rm arcsec}^{-2}$ have recently been detected, and it has been speculated ... More
Geometry of determinants of elliptic operatorsJun 21 1994This paper is essentially a short version of hep-th/9404046. We compute multiplicative anomaly det(AB)/(detA detB) =F(A,B) for elliptic pseudo-differential operators (PDOs) A, B on a closed manifold M in terms of their symbols. We prove that F(A,B)=1 ... More
Para-Hermitian and Para-Quaternionic manifoldsOct 26 2003Jul 06 2005A set of canonical parahermitian connections on an almost paraHermitian manifold is defined. ParaHermitian version of the Apostolov-Gauduchon generalization of the Goldberg-Sachs theorem in General Relativity is given. It is proved that the Nijenhuis ... More
On a saddle point problem arising from magneto-elastic couplingFeb 19 2018This paper deals with the analysis of a coupled problem arising from linear magneto-elastostaticity. The model, which can be derived by an energy principle, gives valuable insight into the coupling mechanism and features a saddle point structure with ... More
On varieties defined by large sets of quadrics and their application to error-correcting codesApr 29 2019Let $U$ be a $({ k-1 \choose 2}-1)$-dimensional subspace of quadrics defined on $\mathrm{PG}(k-1,{\mathbb F})$ with the property that $U$ does not contain reducible quadrics. Let $V(U)$ be the points of $\mathrm{PG}(k-1,{\mathbb F})$ which are zeros of ... More
Relative cohomology of algebraic theoriesAug 08 2014Oct 31 2016We construct relative abelian categories in the sense of MacLane for models of algebraic systems in (co)complete abelian categories. As an example, we consider an analogue of Hochschild-Mitchell cohomology for the functor of Yoneda embedding.
On sets defining few ordinary solidsAug 20 2018Let $\mathcal{S}$ be a set of $n$ points in real four-dimensional space, no four coplanar and spanning the whole space. We prove that if the number of solids incident with exactly four points of $\mathcal{S}$ is less than $Kn^3$ for some $K=o(n^{\frac{1}{7}})$ ... More
Isogeometric Simulation of Thermal Expansion for Twin Screw CompressorsMay 22 2018Isogeometric Analysis (IGA) is a recently introduced computational approach intended to breach the gap between the Finite Element Analysis and the Computer Aided Design worlds. In this work, we apply it to numerically simulate thermal expansion of oil-free ... More
Dynamics of wetting explored with inkjet printingNov 11 2016An inkjet printer head, which is capable of depositing liquid droplets with a resolution of $22$ picoliters and high repeatability, is employed to investigate the wetting dynamics of drops printed on a horizontal plane as well as on a granular monolayer. ... More
Charting the landscape of supercritical string theoryMay 08 2007Special solutions of string theory in supercritical dimensions can interpolate in time between theories with different numbers of spacetime dimensions (via dimension quenching) and different amounts of worldsheet supersymmetry (via c-duality). These solutions ... More