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Eigenvectors of random graphs: Nodal domainsJul 23 2008Nov 02 2009We initiate a systematic study of eigenvectors of random graphs. Whereas much is known about eigenvalues of graphs and how they reflect properties of the underlying graph, relatively little is known about the corresponding eigenvectors. Our main focus ... More

Finding Hidden Cliques in Linear Time with High ProbabilityOct 14 2010We are given a graph $G$ with $n$ vertices, where a random subset of $k$ vertices has been made into a clique, and the remaining edges are chosen independently with probability $\tfrac12$. This random graph model is denoted $G(n,\tfrac12,k)$. The hidden ... More

Determining Omega from Peculiar VelocitiesSep 19 1993The large-scale dynamics of matter is inferred from the observed peculiar velocities of galaxies via the POTENT procedure. The smoothed fields of velocity and mass-density fluctuations are recovered from the current data of about 3000 galaxies. The cosmological ... More

Tribute to an astronomer: the work of Max Ernst on Wilhelm TempelDec 17 2015Jan 11 2016In 1964-1974, the German artist Max Ernst created, with the help of two friends, a series of works (books, movie, paintings) related to the astronomer Wilhelm Tempel. Mixing actual texts by Tempel and artistic features, this series pays homage to the ... More

Spectroscopy of Massive StarsApr 27 2006Dec 06 2006Although rare, massive stars, being the main sources of ionizing radiation, chemical enrichment and mechanical energy in the Galaxy, are the most important objects of the stellar population. This review presents the many different aspects of the main ... More

Hot stars observed by XMM-Newton I. The catalog and the properties of OB starsAug 11 2009Aims : Following the advent of increasingly sensitive X-ray observatories, deep observations of early-type stars became possible. However, the results for only a few objects or clusters have until now been reported and there has been no large survey comparable ... More

Deformation of the Heisenberg Algebra inside $gl(3,\mathbb{K})$Mar 24 2004We study non-trivial deformations of the natural imbedding of the Lie algebra $\fh_1$ of lower triangular matrices (the Heisenberg Lie algebra) into $gl(3,\mathbb{K})$, where $\mathbb{K}=\mathbb{R}$ or $|mathbb{C}$. Our first result is the calculation ... More

Periodic Hamiltonian flows on four dimensional manifoldsOct 13 1995Apr 07 1998We classify the periodic Hamiltonian flows on compact four dimensional symplectic manifolds up to isomorphism of Hamiltonian S^1 spaces. Additionally, we show that all these spaces are Kaehler, that every such space is obtained from a simple model by ... More

Non abelian cohomology of extensions of Lie algebras as Deligne groupoidOct 02 2013In this note we show that the theory of non abelian extensions of a Lie algebra $\mathfrak{g}$ by a Lie algebra $\mathfrak{h}$ can be understood in terms of a differential graded Lie algebra $L$. More precisely we show that the non-abelian cohomology ... More

Flavor and LHC Searches for New PhysicsJan 25 2012Uncovering the physics of electroweak symmetry breaking (EWSB) is the raison-d'etre of the LHC. Flavor questions, it would seem, are of minor relevance for this quest, apart from their role in constraining the possible structure of EWSB physics. In this ... More

A new cohomology theory associated to deformations of Lie algebra morphismsApr 22 2003We introduce a new cohomology theory related to deformations of Lie algebra morphisms. This notion involves simultaneous deformations of two Lie algebras and a homomorphism between them.

Metastable Rank-Condition Supersymmetry Breaking in a Chiral ExampleJul 18 2011We discuss generalizations of Intriligator-Seiberg-Shih (ISS) vacua to chiral models. We study one example, of an s-confining theory, in detail. In the IR, this example reduces to two ISS-like sectors, and exhibits a supersymmetry-breaking vacuum with ... More

Supersymmetry breakingJan 12 2006These lectures provide a simple introduction to supersymmetry breaking. After presenting the basics of the subject and illustrating them in tree-level examples, we discuss dynamical supersymmetry breaking, emphasizing the role of holomorphy and symmetries ... More

Maximal tori in the symplectomorphism groups of Hirzebruch surfacesApr 30 2002We count the conjugacy classes of maximal tori in the groups of symplectomorphisms of S^2 \times S^2 and of the blow-up of CP^2 at a point.

Structure de l'univers - quand l'observation guide la theorie... ou pasJun 05 2015The scientific method is often presented, e.g. to children, as a linear process, starting by a question and ending by the elaboration of a theory, with a few experiments in-between. The reality of the building of science is much more complex, with back-and-forth ... More

Galaxy Biasing: Nonlinear, Stochastic and MeasurableSep 23 1998I describe a general formalism for galaxy biasing (Dekel & Lahav 1998) and its application to measurements of beta (=Omega^0.6/b), e.g. via direct comparisons of light and mass and via redshift distortions. The linear and deterministic relation g=b*d ... More

Competing first passage percolation on random regular graphsSep 12 2011Aug 04 2014We consider two competing first passage percolation processes started from uniformly chosen subsets of a random regular graph on $N$ vertices. The processes are allowed to spread with different rates, start from vertex subsets of different sizes or at ... More

Dual conformal transformations of smooth holographic Wilson loopsOct 23 2016We study dual conformal transformations of minimal area surfaces in $AdS_5 \times S^5$ corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual ... More

Succinct data-structure for nearest colored node in a treeSep 06 2016We give a succinct data-structure that stores a tree with color for each node, and allows finding, given a node x and a color alpha, the nearest node to x with color alpha. This results improves the O(n log n)-bits structure of Gawrychowski et al.~[CPM ... More

Algebraic Curves for Factorized String SolutionsFeb 04 2013We show how to construct an algebraic curve for factorized string solution in the context of the AdS/CFT correspondence. We define factorized solutions to be solutions where the flat-connection becomes independent of one of the worldsheet variables by ... More

Characteristic Scales in Galaxy FormationJan 23 2004Recent data, e.g. from SDSS and 2dF, reveal a robust bi-modality in the distribution of galaxy properties, with a characteristic transition scale at stellar mass M_*~3x10^{10} Msun (near L_*), corresponding to virial velocity V~100 km/s. Smaller galaxies ... More

Wilson Loops and Minimal Surfaces Beyond the Wavy ApproximationJan 17 2015We study Euclidean Wilson loops at strong coupling using the AdS/CFT correspondence, where the problem is mapped to finding the area of minimal surfaces in Hyperbolic space. We use a formalism introduced recently by Kruczenski to perturbatively compute ... More

Dual conformal transformations of smooth holographic Wilson loopsOct 23 2016Nov 11 2016We study dual conformal transformations of minimal area surfaces in $AdS_5 \times S^5$ corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual ... More

A note on the Split to Block Vertex Deletion problemJun 24 2019Jun 27 2019In the Split to Block Vertex Deletion (SBVD) problem the input is a split graph $G$ and an integer $k$, and the goal is to decide whether there is a set $S$ of at most $k$ vertices such that $G-S$ is a block graph. In this paper we give an algorithm for ... More

l-path vertex cover is easier than l-hitting set for small lJun 22 2019In the $l$-path vertex cover problem the input is an undirected graph $G$ and an integer $k$. The goal is to decide whether there is a set of vertices $S$ of size at most $k$ such that $G-S$ does not contain a path with $l$ vertices. In this paper we ... More

Faster parameterized algorithm for Cluster Vertex DeletionJan 22 2019In the Cluster Vertex Deletion problem the input is a graph $G$ and an integer $k$. The goal is to decide whether there is a set of vertices $S$ of size at most $k$ such that the deletion of the vertices of $S$ from $G$ results a graph in which every ... More

Phase-Space Structure & Substructure of Dark HalosMar 07 2004A method is presented for computing the 6-D phase-space density f(x,v) and its PDF v(f) in an N-body system. It is based on Delaunay tessellation, yielding v(f) with a fixed smoothing window over a wide f range, independent of the sampling resolution. ... More

Do Spirals and Ellipticals Trace the Same Velocity Field?Sep 27 1993We test the hypothesis that the velocity field derived from Tully-Fisher measurements of spiral galaxies, and that derived independently from Dn-sigma measurements of ellipticals and S0s, are noisy versions of the same underlying velocity field. The radial ... More

Gravitational Quenching by Clumpy Accretion in Cool Core Clusters: Convective Dynamical Response to OverheatingAug 05 2010Dec 09 2011Many galaxy clusters pose a "cooling-flow problem", where the observed X-ray emission from their cores is not accompanied by enough cold gas or star formation. A continuous energy source is required to balance the cooling rate over the whole core volume. ... More

Gravitational Quenching in Massive Galaxies and Clusters by Clumpy AccretionJul 09 2007Nov 05 2007We consider a simple gravitational-heating mechanism for the long-term quenching of cooling flows and star formation in massive dark-matter haloes hosting ellipticals and clusters. The virial shock heating in haloes >10^12 Mo triggers quenching in 10^12-13 ... More

Galaxy Bimodality due to Cold Flows and Shock HeatingDec 13 2004Dec 17 2005We address the origin of the robust bi-modality observed in galaxy properties about a characteristic stellar mass ~3x10^{10}Msun. Less massive galaxies tend to be ungrouped blue star-forming discs, while more massive galaxies are typically grouped red ... More

Virial shocks in galactic haloes?Feb 08 2003Jul 14 2003We investigate the conditions for the existence of an expanding virial shock in the gas falling within a spherical dark-matter halo. The shock relies on pressure support by the shock-heated gas behind it. When the radiative cooling is efficient compared ... More

Gauge Theories in $AdS_5$ and Fine-Lattice DeconstructionSep 22 2004Sep 23 2004The logarithmic energy dependence of gauge couplings in AdS_5 emerges almost automatically when the theory is deconstructed on a coarse lattice. Here we study the theory away from the coarse-lattice limit. While we cannot analytically calculate individual ... More

Structure-Aware Classification using Supervised Dictionary LearningSep 29 2016In this paper, we propose a supervised dictionary learning algorithm that aims to preserve the local geometry in both dimensions of the data. A graph-based regularization explicitly takes into account the local manifold structure of the data points. A ... More

Convexity package for momentum maps on contact manifoldsOct 29 2009Mar 10 2010Let a torus T act effectively on a compact connected cooriented contact manifold, and let Psi be the natural momentum map on the symplectization. We prove that, if dim T > 2, the union of the origin with the image of Psi is a convex polyhedral cone, the ... More

A geometric characterization of the classical Lie algebrasJul 07 2017A nonzero element x in a Lie algebra g over a field F with Lie product [ , ] is called a extremal element if [x, [x, g]] is contained in Fx. Long root elements in classical Lie algebras are examples of extremal elements. Arjeh Cohen et al. initiated the ... More

X-ray and optical spectroscopy of the massive young open cluster IC1805Aug 16 2016Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC1805 open cluster is very interesting as it hosts the O4If$^+$ star HD15570 thought to be in an evolutionary ... More

Completely integrable torus actions on complex manifolds with fixed pointsMar 05 2012Dec 15 2012We show that if a holomorphic $n$ dimensional compact torus action on a compact connected complex manifold of complex dimension $n$ has a fixed point then the manifold is equivariantly biholomorphic to a smooth toric variety.

The Graver Complexity of Integer ProgrammingSep 10 2007Nov 22 2007In this article we establish an exponential lower bound on the Graver complexity of integer programs. This provides new type of evidence supporting the presumable intractability of integer programming. Specifically, we show that the Graver complexity ... More

Centered complexity one Hamiltonian torus actionsNov 23 1999Feb 23 2000We consider symplectic manifolds with Hamiltonian torus actions which are "almost but not quite completely integrable": the dimension of the torus is one less than half the dimension of the manifold. We provide a complete set of invariants for such spaces ... More

The Gromov width of complex GrassmanniansMay 20 2004Aug 24 2005We show that the Gromov width of the Grassmannian of complex k-planes in C^n is equal to one when the symplectic form is normalized so that it generates the integral cohomology in degree 2. We deduce the lower bound from more general results. For example, ... More

The Morse-Bott-Kirwan condition is localJul 14 2014Nov 09 2016Kirwan identified a condition on a smooth function under which the usual techniques of Morse-Bott theory can be applied to this function. We prove that if a function satisfies this condition locally then it also satisfies the condition globally. As an ... More

The Morse-Bott-Kirwan condition is localJul 14 2014Kirwan identified a condition on a smooth function under which the usual techniques of Morse-Bott theory can be applied to this function. We prove that if a function satisfies this condition locally then it also satisfies the condition globally. As an ... More

Simultaneous deformations and Poisson geometryFeb 13 2012Oct 07 2014We consider the problem of deforming simultaneously a pair of given structures. We show that such deformations are governed by an L-infinity algebra, which we construct explicitly. Our machinery is based on Th. Voronov's derived bracket construction. ... More

Lorentz Violation and Superpartner MassesMay 19 2006Jan 09 2007We consider Lorentz violation in supersymmetric extensions of the standard model. We perform a spurion analysis to show that, in the simplest natural constructions, the resulting supersymmetry-breaking masses are tiny. In the process, we argue that one ... More

Circle and torus actions on equal symplectic blow-ups of CP^2Jan 02 2005A manifold obtained by k simultaneous symplectic blow-ups of CP^2 of equal sizes epsilon (where the size of CP^1 \subset CP^2 is one) admits an effective two dimensional torus action if k <= 3 and admits an effective circle action if (k-1)epsilon < 1. ... More

Spin Correlations in Top-Quark Pair Production at $e^+e^-$ CollidersJun 24 1996Aug 30 1996We show that top-quark pairs are produced in an essentially unique spin configuration in polarized $e^+e^-$ colliders at all energies above the threshold region. Since the directions of the electroweak decay products of polarized top-quarks are strongly ... More

Deep penetration fluorescence imaging through dense yeast cells suspensions using Airy beamsFeb 24 2019We propose a new method to image fluorescent objects through turbid media base on Airy beam scanning. This is achieved by using the non-diffractive nature of Airy beams, namely their ability to maintain their shape while penetrating through a highly scattering ... More

Counting to Ten with Two Fingers: Compressed Counting with Spiking NeuronsFeb 27 2019Mar 03 2019We consider the task of measuring time with probabilistic threshold gates implemented by bio-inspired spiking neurons. In the model of spiking neural networks, network evolves in discrete rounds, where in each round, neurons fire in pulses in response ... More

X-ray emission from interacting massive binaries: a review of 15 years of progressSep 22 2015Previous generations of X-ray observatories revealed a group of massive binaries that were relatively bright X-ray emitters. This was attributed to emission of shock-heated plasma in the wind-wind interaction zone located between the stars. With the advent ... More

On unitality conditions for Hom-associative algebrasApr 30 2009Jul 21 2009In hom-associative structures, the associativity condition $(xy)z=x(yz)$ is twisted to $\alpha(x)(yz) = (xy)\alpha(z)$, with $\alpha$ a map in the appropriate category. In the present paper, we consider two different unitality conditions for hom-associative ... More

Hamiltonian group actions on exact symplectic manifolds with proper momentum maps are standardJul 13 2016We give a complete characterization of Hamiltonian actions of compact Lie groups on exact symplectic manifolds with proper momentum maps. We deduce that every Hamiltonian action of a compact Lie group on a contractible symplectic manifold with a proper ... More

Complete invariants for Hamiltonian torus actions with two dimensional quotientsFeb 18 2002Dec 14 2003We study torus actions on symplectic manifolds with proper moment maps in the case that each reduced space is two-dimensional. We provide a complete set of invariants for such spaces. Our proof uses sheaves of groupoids of Hamiltonian spaces.

High-resolution X-ray spectroscopy of Theta CarAug 25 2008Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the ... More

Blockers for Triangulations of a Convex Polygon and a Geometric Maker-Breaker GameDec 31 2017Let $G$ be a complete convex geometric graph whose vertex set $P$ forms a convex polygon $C$, and let $F$ be a family of subgraphs of $G$. A blocker for $F$ is a set of edges, of smallest possible size, that contains a common edge with every element of ... More

Reconstruction of the Path GraphDec 31 2017Let $P$ be a set of $n \geq 5$ points in convex position in the plane. The path graph $G(P)$ of $P$ is an abstract graph whose vertices are non-crossing spanning paths of $P$, such that two paths are adjacent if one can be obtained from the other by deleting ... More

Distinguishing symplectic blowups of the complex projective planeJul 20 2014A symplectic manifold that is obtained from the complex projective plane by k blowups is encoded by k+1 parameters: the size of the initial complex projective plane, and the sizes of the blowups. We determine which values of these parameters yield symplectomorphic ... More

Effective Field Theory Amplitudes the On-Shell Way: Scalar and Vector Couplings to GluonsSep 25 2018Mar 02 2019We use on-shell methods to calculate tree-level effective field theory (EFT) amplitudes, with no reference to the EFT operators. Lorentz symmetry, unitarity and Bose statistics determine the allowed kinematical structures. As a by-product, the number ... More

Strongly Contracting Geodesics in Outer SpaceDec 08 2008Jun 18 2010We study the Lipschitz metric on Outer Space and prove that fully irreducible elements of Out(F_n) act by hyperbolic isometries with axes which are strongly contracting. As a corollary, we prove that the axes of fully irreducible automorphisms in the ... More

Revisiting Tietze-Nakajima - Local and Global Convexity for MapsJan 25 2007Nov 19 2009A theorem of Tietze and Nakamija, from 1928, asserts that if a subset X of R^n is closed, connected, and locally convex, then it is convex. We give an analogous "local to global convexity" theorem when the inclusion map of X to R^n is replaced by a map ... More

On Hopf 2-algebrasAug 17 2009Apr 09 2010Our main goal in this paper is to translate the diagram relating groups, Lie algebras and Hopf algebras to the corresponding 2-objects, i.e. to categorify it. This is done interpreting 2-objects as crossed modules and showing the compatibility of the ... More

Shortening the Hofer length of Hamiltonian circle actionsDec 04 2009Dec 09 2013A Hamiltonian circle action on a compact symplectic manifold is known to be a closed geodesic with respect to the Hofer metric on the group of Hamiltonian diffeomorphisms. If the momentum map attains its minimum or maximum at an isolated fixed point with ... More

Non-Compact Symplectic Toric ManifoldsJul 16 2009Jul 22 2015A key result in equivariant symplectic geometry is Delzant's classification of compact connected symplectic toric manifolds. The moment map induces an embedding of the quotient of the manifold by the torus action into the dual of the Lie algebra of the ... More

Classification of Hamiltonian torus actions with two dimensional quotientsSep 30 2011May 09 2012We construct all possible Hamiltonian torus actions for which all the non-empty reduced spaces are two dimensional (and not single points) and the manifold is connected and compact, or, more generally, the moment map is proper as a map to a convex set. ... More

Topology of complexity one quotientsOct 02 2018We describe of the topology of the geometric quotients of 2n dimensional compact connected symplectic manifolds with n-1 dimensional torus actions. When the isotropy weights at each fixed point are in general position, the quotient is homeomorphic to ... More

Integrability of Green-Schwarz Sigma Models with BoundariesJun 17 2011Nov 08 2011We construct integrability preserving boundary conditions for Green-Schwarz sigma-models on semi-symmetric spaces. The boundary conditions are expressed as gluing conditions of the flat-connection, using an involutive metric preserving automorphism. We ... More

Feedback and the fudamental line of low-luminosity LSB/dwarf galaxiesOct 20 2002Dec 12 2003We study in simple terms the role of feedback in establishing the scaling relations of low-surface-brightness and dwarf galaxies with stellar masses in the range 6x10^5 <M*< 3x10^10 Msun. These galaxies, as measured from SDSS and in the Local Group, show ... More

Constructing Merger Trees that Mimic N-Body SimulationsAug 13 2007Oct 13 2007We present a simple and efficient empirical algorithm for constructing dark-matter halo merger trees that reproduce the distribution of trees in the Millennium cosmological $N$-body simulation. The generated trees are significantly better than EPS trees. ... More

The lognormal-like statistics of a stochastic squeeze processJan 05 2017Oct 26 2017We analyze the full statistics of a stochastic squeeze process. The model's two parameters are the bare stretching rate~$w$, and the angular diffusion coefficient~$D$. We carry out an exact analysis to determine the drift and the diffusion coefficient ... More

Cosmic Flows: A Status ReportMay 27 2001Jun 03 2001We give a brief review of recent developments in the study of the large-scale velocity field of galaxies since the international workshop on Cosmic Flows held in July 1999 in Victoria, B.C. Peculiar velocities (PVs) yield a tight and unique constraint ... More

Self-Duality of Green-Schwarz Sigma-ModelsJan 02 2011Jan 11 2011We study fermionic T-duality symmetries of integrable Green-Schwarz sigma-models on Anti-de-Sitter backgrounds with Ramond-Ramond fluxes, constructed as Z_4 supercosets of superconformal algebras. We find three algebraic conditions that guarantee self-duality ... More

An analytic solution for the minimal bathtub toy model: challenges in the star-formation history of high-z galaxiesFeb 10 2014We study the minimal ``bathtub" toy model as an analytic tool for capturing key processes of galaxy evolution and identifying robust successes and challenges in reproducing observations at high redshift. The source and sink terms of the continuity equations ... More

Towards a Resolution of the Galactic Spin Crisis: Mergers, Feedback, and Spin SegregationJan 11 2002We model in simple terms the angular-momentum problems of galaxy formation in CDM cosmologies, and identify the key elements of a scenario that may solve them. The buildup of angular momentum is modeled via dynamical friction and tidal stripping in a ... More

Linear representations of Aut(F_r) on the homology of representation varietiesOct 11 2012Let G be a compact semisimple linear Lie group. We study the action of Aut(F_r) on the space H_*(G^r;\QQ). We compute the image of this representation and prove that it only depends on the rank of the Lie algebra of G. We show that the kernel of this ... More

Normalizers and centralizers of cyclic subgroups generated by lone axis fully irreducible outer automorphismsMar 23 2016Jul 03 2016We let $\varphi$ be an ageometric fully irreducible outer automorphism so that its Handel-Mosher axis bundle consists of a single unique axis. We show that the centralizer $Cen(\langle\varphi\rangle)$ of the cyclic subgroup generated by $\varphi$ equals ... More

Asymmetry of Outer SpaceOct 28 2009Mar 23 2011We study the asymmetry of the Lipschitz metric d on Outer space. We introduce an (asymmetric) Finsler norm that induces d. There is an Out(F_n)-invariant potential \Psi on Outer space such that when the Lipschitz norm is corrected by the derivative of ... More

Duality after Supersymmetry BreakingJun 10 1998Starting with two supersymmetric dual theories, we imagine adding a chiral perturbation that breaks supersymmetry dynamically. At low energy we then get two theories with soft supersymmetry-breaking terms that are generated dynamically. With a canonical ... More

Tensor products and support varieties for some noncocommutative Hopf algebrasNov 30 2016We explore questions of projectivity and tensor products of modules for finite dimensional Hopf algebras. We construct many classes of examples in which tensor powers of nonprojective modules are projective and tensor products of modules in one order ... More

Smooth Lie group actions are parametrized diffeological subgroupsDec 01 2010We show that every effective smooth action of a Lie group G on a manifold M is a diffeomorphism from G onto its image in Diff(M), where the image is equipped with the subset diffeology of the functional diffeology.

WIMPless Dark Matter from Non-Abelian Hidden Sectors with Anomaly-Mediated Supersymmetry BreakingFeb 01 2011In anomaly-mediated supersymmetry breaking (AMSB) models, superpartner masses are proportional to couplings squared. Their hidden sectors therefore naturally contain WIMPless dark matter, particles whose thermal relic abundance is guaranteed to be of ... More

Support varieties for finite tensor categories: Complexity and tensor productsMay 16 2019We advance support variety theory for finite tensor categories. We prove that the dimension of the support variety of an object is equal to the rate of growth of a minimal projective resolution as measured by Frobenius-Perron dimension. We ask when the ... More

Solvability of a class of braided fusion categoriesMay 10 2012We show that a weakly integral braided fusion category C such that every simple object of C has Frobenius-Perron dimension at most 2 is solvable. In addition, we prove that such a fusion category is group-theoretical in the extreme case where the universal ... More

On fusion categories with few irreducible degreesMar 11 2011Nov 04 2011We prove some results on the structure of certain classes of integral fusion categories and semisimple Hopf algebras under restrictions on the set of its irreducible degrees.

Duality in the Presence of Supersymmetry BreakingJan 22 1998Sep 01 1998We study Seiberg duality for N=1 supersymmetric QCD with soft supersymmetry-breaking terms. We generate the soft terms through gauge mediation by coupling two theories related by Seiberg duality to the same supersymmetry-breaking sector. In this way, ... More

Support Vector Machines for Current Status DataMay 05 2015Current status data is a data format where the time to event is restricted to knowledge of whether or not the failure time exceeds a random monitoring time. We develop a support vector machine learning method for current status data that estimates the ... More

Holographic assembly of quasicrystalline photonic heterostructuresJun 13 2005Quasicrystals have a higher degree of rotational and point-reflection symmetry than conventional crystals. As a result, quasicrystalline heterostructures fabricated from dielectric materials with micrometer-scale features exhibit interesting and useful ... More

Compressing Communication in Distributed ProtocolsMay 31 2015Aug 04 2015We show how to compress communication in distributed protocols in which parties do not have private inputs. More specifically, we present a generic method for converting any protocol in which parties do not have private inputs, into another protocol where ... More

Flavored Gauge-MediationMar 01 2011Feb 23 2012The messengers of Gauge-Mediation Models can couple to standard-model matter fields through renormalizable superpotential couplings. These matter-messenger couplings generate generation-dependent sfermion masses and are therefore usually forbidden by ... More

Cohomology of finite tensor categories: duality and Drinfeld centersJul 23 2018Feb 15 2019This work concerns the finite generation conjecture for finite tensor categories (Etingof and Ostrik '04), which proposes that for such a category C, the self-extension algebra of the unit Ext*_C(1,1) is a finitely generated algebra and that, for each ... More

Tensor functors between Morita duals of fusion categoriesJul 10 2014Oct 04 2016Given a fusion category $\mathcal{C}$ and an indecomposable $\mathcal{C}$-module category $\mathcal{M}$, the fusion category $\mathcal{C}^*_\mathcal{M}$ of $\mathcal{C}$-module endofunctors of $\mathcal{M}$ is called the (Morita) dual fusion category ... More

Mapping tori of small dilatation irreducible train-track mapsSep 25 2012Nov 23 2012We prove that for every P there is a bound B depending only on P so that the mapping torus of every P--small irreducible train-track map can be obtained by surgery from one of B mapping tori. We show that given an integer P>0 there is a bound $M$ depending ... More

Metallicity-Dependent quenching of Star Formation at High Redshift in Small GalaxiesJun 01 2011May 03 2012[abridged] The star formation rates (SFR) of low-metallicity galaxies depend sensitively on the gas metallicity, because metals are crucial to mediating the transition from intermediate-temperature atomic gas to cold molecular gas, a necessary precursor ... More

Resolving the Spin Crisis: Mergers and FeedbackJan 19 2002We model in simple terms the angular momentum (J) problem of galaxy formation in CDM, and identify the key elements of a scenario that can solve it. The buildup of J is modeled via dynamical friction and tidal stripping in mergers. This reveals how over-cooling ... More

The Dissipative Merger Progenitors of Elliptical GalaxiesMar 20 2006We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the "tilt" of the "fundamental plane" and the steep decline of density with mass. We show that such tilts ... More

Steady Outflows in Giant Clumps of High-z Disk Galaxies During Migration and Growth by AccretionFeb 18 2013Mar 18 2013We predict the evolution of giant clumps undergoing star-driven outflows in high-z gravitationally unstable disk galaxies. We find that the mass loss is expected to occur through a steady wind over many tens of free-fall times (t_ff ~ 10 Myr) rather than ... More

Survival of Star-Forming Giant Clumps in High-Redshift GalaxiesJan 05 2010May 05 2010We investigate the effects of radiation pressure from stars on the survival of the star-forming giant clumps in high-redshift massive disc galaxies, during the most active phase of galaxy formation. The clumps, typically of mass ~10^8-10^9 Msun and radius ... More

ImageNet-trained deep neural network exhibits illusion-like response to the Scintillating GridJul 21 2019Deep neural network (DNN) models for computer vision are now capable of human-level object recognition. Consequently, similarities in the performance and vulnerabilities of DNN and human vision are of great interest. Here we characterize the response ... More

Online Learning with Switching Costs and Other Adaptive AdversariesFeb 18 2013Jun 01 2013We study the power of different types of adaptive (nonoblivious) adversaries in the setting of prediction with expert advice, under both full-information and bandit feedback. We measure the player's performance using a new notion of regret, also known ... More

Universal Merger Histories of Dark-Matter HaloesMar 10 2009Dec 07 2009We study merger histories of dark-matter haloes in a suite of N-body simulations that span different cosmological models. The simulated cases include the up-to-date WMAP5 cosmology and other test cases based on the Einstein-deSitter cosmology with different ... More

Dynamic all scores matrices for LCS scoreAug 10 2018The problem of aligning two strings A,B in order to determine their similarity is fundamental in the field of pattern matching. An important concept in this domain is the "all scores matrix" that encodes the local alignment comparison of two strings. ... More