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Transport Through Self-Assembled Monolayer Molecular Junctions: Role of In-Plane DephasingJul 20 2014Self-assembled-monolayer (SAM) molecular junctions (MJs) constitute a promising building block candidate for future molecular electronic devices. Transport properties of SAM-MJs are usually calculate using either the phenomenological Simmons model, or ... More

The effect of fluctuations - thermal and otherwise - on the temperature dependence of thermopower in aromatic chain single-molecule junctionsMar 03 2013We report a theoretical study of the thermopower of single-molecule junctions, with focus on phenyl-based molecular junctions. In contrast to prior studies, thermal fluctuations of the torsional angle between the phenyl rings and variations in the position ... More

Dynamical coupling and negative differential resistance from interactions across the molecule-electrode interface in molecular junctionsSep 11 2013Negative differential resistance - a decrease in current with increasing bias voltage - is a counter-intuitive effect that is observed in various molecular junctions. Here, we present a novel mechanism that may be responsible for such an effect, based ... More

Quantum Hall Criticality, Superconductor-Insulator Transition and Quantum PercolationJun 01 2004A model consisting of a mixture of superconducting and quantum links is proposed to describe the integer quantum Hall transition. The quantum links correspond to tunneling of electrons between trajectories trapped in adjacent potential valleys, while ... More

Interplay between Dephasing and Geometry and Directed Heat Flow in Exciton Transfer ComplexesOct 11 2015The striking efficiency of energy transfer in natural photosynthetic systems and the recent evidence of long-lived quantum coherence in biological light harvesting complexes has triggered much excitement, due to the evocative possibility that these systems ... More

Origin of thermoelectric response fluctuations in single-molecule junctionsNov 20 2012The thermoelectric response of molecular junctions exhibits large fluctuations, as observed in recent experiments [e.g. Malen J. A. {\sl et al.}, Nano Lett. {\bf 10}, 3406 (2009)]. These were attributed to fluctuations in the energy alignment between ... More

Pair correlations and the survival of superconductivity in and around a super-conducting impurityMay 25 2006Feb 15 2007The problem of the survival of superconductivity in a small super-conducting grain placed in a metal substrate is addressed. For this aim the pair correlations and super-conducting gap around and inside a negative-U impurity in one and two dimensions ... More

Charge density wave in hidden order state of URu$_2$Si$_2$Oct 05 2010We argue that the hidden order state in URu$_2$Si$_2$ will induce a charge density wave. The modulation vector of the charge density wave will be twice that of the hidden order state, $Q_{CDW} = 2Q_{HO}$. To illustrate how the charge density wave arises ... More

Microwave-mediated heat transport through a quantum dotFeb 06 2012The thermoelectric effect in a quantum dot (QD) attached to two leads in the presence of microwave fields is studied by using the Keldysh nonequilibrium Green function technique. When the microwave is applied only on the QD and in the linear-response ... More

Mechanical Tuning of Conductance and Thermopower in Helicene Molecular JunctionsApr 08 2015Helicenes are inherently chiral polyaromatic molecules composed of all-ortho fused benzene rings possessing a spring-like structure. Here, using a combination of density functional theory and tight-binding calculations, it is demonstrated that controlling ... More

Negative differential conductance in molecular junctions: an overview of experiment and theoryMay 28 2015One of the ultimate goals of molecular electronics is to create technologies that will complement - and eventually supersede - Si-based microelectronics technologies. To reach this goal, electronic properties that mimic at least some of the electrical ... More

Energy flow and thermo-electricity in atomic and molecular junctionsOct 02 2009Oct 15 2010Advances in the fabrication and characterization of nanoscale systems now allow for a deeper understanding of one of the most basic issues in science and technology: the flow of energy at the microscopic level. In this Colloquium we survey recent advances ... More

Enhanced Thermoelectric Performance in Hybrid Nanoparticle--Single Molecule JunctionsJun 06 2015It was recently suggested that molecular junctions would be excellent elements for efficient and high-power thermoelectric energy conversion devices. However, experimental measurements of thermoelectric conversion in molecular junctions have indicated ... More

Dimer mean-field model for the Ising spin glassDec 15 2009A dimer mean-field model for the Ising spin-glass is presented. Despite its simplicity it captures some of the essential features of the spin-glass physics. The distribution of the single-spin magnetization is determined from a self-consistent integral ... More

Maintaining the local temperature below the critical value in thermally out of equilibrium superconducting wiresJul 15 2009A generalized theory of open quantum systems combined with mean-field theory is used to study a superconducting wire in contact with thermal baths at different temperatures. It is shown that, depending on the temperature of the colder bath, the temperature ... More

Thermal effects - an alternative mechanism for plasmonic-assisted photo-catalysisFeb 08 2019Recent experiments claimed that the enhancement of catalytic reaction rates occurs via the reduction of activation barriers driven by non-equilibrium ("hot") electrons in plasmonic metal nano-particles. These experiments place plasmonic photo-catalysis ... More

A unifying model for several two-dimensional phase transitionsSep 30 2004Oct 01 2004A relatively simple and physically transparent model based on quantum percolation and dephasing is employed to construct a global phase diagram which encodes and unifies the critical physics of the quantum Hall, "two-dimensional metal-insulator", classical ... More

The Molecular Photo-Cell: Quantum Transport and Energy Conversion at Strong Non-EquilibriumJun 18 2014Jan 26 2015Non-equilibrium transport properties and energy conversion performance of a molecular photo-voltaic cell are analyzed using the Lindblad master equation within the open quantum systems approach. The method allows us to calculate the dynamics of a system ... More

Nature of the superconductor-insulator transition in disordered superconductorsOct 29 2007As a superconducting thin film becomes disordered and subject to an increasing magnetic field, a point is reached when it undergoes a transition from a superconducting to an insulating state. We use the Bogoliubov-De-Gennes equations and a novel Monte-Carlo ... More

Theory of Magneto-resistance of Disordered Superconducting FilmsMay 16 2005Recent experimental studies of magneto-resistance in disordered superconducting thin films reveal a huge peak (about 5 orders of magnitude). While it may be expected that magnetic field destroys superconductivity, leading to an enhanced resistance, attenuation ... More

Distribution of twisted Kloosterman sums modulo prime powersJan 27 2008Mar 31 2008In this note we study Kloosterman sums twisted by a multiplicative characters modulo a prime power. We show, by an elementary calculation, that these sums become equidistributed on the real line with respect to a suitable measure.

A refinement of strong multiplicity one for spectra of hyperbolic manifoldsAug 15 2011Sep 09 2011Let $\calM_1$ and $\calM_2$ denote two compact hyperbolic manifolds. Assume that the multiplicities of eigenvalues of the Laplacian acting on $L^2(\calM_1)$ and $L^2(\calM_2)$ (respectively, multiplicities of lengths of closed geodesics in $\calM_1$ and ... More

A Uniform Strong Spectral Gap for Congruence Covers of a compact quotient of PSL(2,R)^dFeb 18 2010May 19 2010The existence of a strong spectral gap for lattices in semi-simple Lie groups is crucial in many applications. In particular, for arithmetic lattices it is useful to have bounds for the strong spectral gap that are uniform in the family of congruence ... More

Approximation of points in the plane by generic lattice orbitsJun 28 2016We give upper and lower bounds for Diophantine exponents measuring how well a point in the plane can be approximated by points in the orbit of a lattice $\Gamma<\mathrm{SL}_2(\mathbb{R})$ acting linearly on $\mathbb{R}^2$. Our method gives bounds that ... More

Distribution of holonomy about closed geodesics in a product of hyperbolic planesNov 02 2009Aug 28 2010Let $\calM=\Gamma\bs \calH^{(n)}$, where $\calH^{(n)}$ is a product of $n+1$ hyperbolic planes and $\Gamma\subset\PSL(2,\bbR)^{n+1}$ is an irreducible cocompact lattice. We consider closed geodesics on $\calM$ that propagate locally only in one factor. ... More

On matrix elements for the quantized cat map modulo prime powersFeb 21 2008Sep 18 2008The quantum cat map is a model for a quantum system with underlying chaotic dynamics. In this paper we study the matrix elements of smooth observables in this model, when taking arithmetic symmetries into account. We give explicit formulas for the matrix ... More

Hybrid trace formula for a non-uniform irreducible lattice in $\PSL_2(\bbR)^n$Aug 29 2012Dec 05 2012In a series of lectures Selberg introduced a trace formula on the space of hybrid Maass-modular forms of an irreducible uniform lattice in $\PSL_2(\bbR)^n$. In this paper we derive the analogous formula for a non-uniform lattice and use it to study the ... More

Large Tunable Thermophase in Superconductor -- Quantum Dot -- Superconductor Josephson JunctionsDec 28 2015Oct 30 2016In spite of extended efforts, detecting thermoelectric effects in superconductors have proven to be a challenging task, due to the inherent superconducting particle-hole symmetry. Here we present a theoretical study of an experimentally attainable Superconductor ... More

Tunable Thermal Switching via DNA-Based Nano DevicesJul 23 2012Dec 28 2012DNA has a well-defined structural transition -- the denaturation of its double-stranded form into two single strands -- that strongly affects its thermal transport properties. We show that, according to a widely implemented model for DNA denaturation, ... More

How Kondo Holes Create Intense Nanoscale Heavy-Fermion Hybridization DisorderOct 18 2011Replacing a magnetic atom by a spinless atom in a heavy fermion compound generates a quantum state often referred to as a 'Kondo-hole'. No experimental imaging has been achieved of the atomic-scale electronic structure of a Kondo-hole, or of their destructive ... More

Driving denaturation: Nanoscale thermal transport as a probe of DNA meltingDec 30 2010May 18 2011DNA denaturation has long been a subject of intense study due to its relationship to DNA transcription and its fundamental importance as a nonlinear, structural transition. Many aspects of this phenomenon, however, remain poorly understood. Existing models ... More

On the Pair Correlation Density for Hyperbolic AnglesAug 03 2013May 07 2014Let $\Gamma< \mathrm{PSL}_2(\mathbb{R})$ be a lattice and $\omega\in \mathbb{H}$ a point in the upper half plane. We prove the existence and give an explicit formula for the pair correlation density function for the set of angles between geodesic rays ... More

A Quantitative Oppenheim Theorem for generic ternary quadratic formsJun 08 2016We prove a quantitative version of Oppenheim's conjecture for generic ternary indefinite quadratic forms. Our results are inspired by and analogous to recent results for diagonal quadratic forms due to Bourgain.

Dynamical Embedding in Cubical Shifts & the Topological Rokhlin and Small Boundary PropertiesJan 25 2013Nov 20 2013According to a conjecture of Lindenstrauss and Tsukamoto, a topological dynamical system $(X,T)$ is embeddable in the $d$-cubical shift $(([0,1]^{d})^{\mathbb{Z}},\ shift)$ if both its mean dimension and periodic dimension are strictly bounded by $\frac{d}{2}$. ... More

Mean Dimension & Jaworski-type TheoremsAug 26 2012Oct 20 2015According to the celebrated Jaworski Theorem, a finite dimensional aperiodic dynamical system $(X,T)$ embeds in the $1$-dimensional cubical shift $([0,1]^{\mathbb{Z}},shift)$. If $X$ admits periodic points (still assuming $\dim(X)<\infty$) then we show ... More

Logarithm laws for one parameter unipotent flowsMay 26 2011Sep 30 2016We prove logarithm laws and shrinking target properties for unipotent flows on the homogenous space $\Gamma\bs G$ with $G=\SL_2(\bbR)^{r_1}\times\SL_2(\bbC)^{r_2}$ and $\Gamma\subseteq G$ an irreducible non-uniform lattice. Our method relies on certain ... More

Effective equidistribution of shears and applicationsJun 18 2015A "shear" is a unipotent translate of a cuspidal geodesic ray in the quotient of the hyperbolic plane by a non-uniform discrete subgroup of PSL(2,R), possibly of infinite co-volume. We prove the regularized equidistribution of shears under large translates ... More

The evolution of microRNA-regulation in duplicated genes facilitates expression divergenceFeb 26 2008Background: The evolution of microRNA regulation in metazoans is a mysterious process: MicroRNA sequences are highly conserved among distal organisms, but on the other hand, there is no evident conservation of their targets. Results: We study this extensive ... More

On the functional properties of microRNA-mediated feed forward loopsFeb 23 2008Feb 26 2008Motivation: Recent studies of genomic-scale regulatory networks suggested that a feed-forward loop (FFL) circuitry is a key component of many such networks. This led to a study of the functional properties of different FFL types, where the regulatory ... More

Geometry and arithmetic of certain log K3 surfacesNov 04 2015Let $k$ be a field of characteristic $0$. In this paper we describe a classification of smooth log K3 surfaces $X$ over $k$ whose geometric Picard group is trivial and which can be compactified into del Pezzo surfaces. We show that such an $X$ can always ... More

Quasi-unital $\infty$-CategoriesSep 30 2012Sep 13 2013Inspired by Lurie's theory of quasi-unital algebras we prove an analogous result for $\infty$-categories. In particular, we show that the unital structure of an $\infty$-category can be uniquely recovered from the underlying non-unital structure once ... More

Integral points on conic log K3 surfacesNov 16 2015Adapting a powerful method of Swinnerton-Dyer, we give explicit sufficient conditions for the existence of integral points on certain schemes which are fibered into affine conics. This includes, in particular, cases where the scheme is geometrically a ... More

Tales of HoffmanJul 07 2004Jul 29 2004Hofmman's bound on the chromatic number of a graph states that $\chi \geq 1 - \frac {\lambda_1} {\lambda_n}$. Here we show that the same bound, or slight modifications of it, hold for several graph parameters related to the chromatic number: the vector ... More

The Section Conjecture for Graphs and Conical CurvesApr 26 2013In this paper we formulate and prove a combinatorial version of the section conjecture for finite groups acting on finite graphs. We apply this result to the study of rational points and show that finite descent is the only obstruction to the Hasse principle ... More

Quaternionic Wiener Algebras, Factorization and ApplicationsMay 26 2016May 27 2016We define an almost periodic extension of the Wiener algebras in the quaternionic setting and prove a Wiener-Levy type theorem for it, as well as extending the theorem to the matrix-valued case. We prove a Wiener-Hopf factorization theorem for the quaternionic ... More

Unbinned halo-independent methods for emerging dark matter signalsNov 17 2014Halo-independent methods for analyzing direct detection experiments can provide robust results while making no assumptions about the dark matter halo in our galaxy. We extend existing methods to the case of unbinned data, which is especially well suited ... More

Ambidexterity and the universality of finite spansMar 28 2017Jan 28 2019Pursuing the notions of ambidexterity and higher semiadditivity as developed by Hopkins and Lurie, we prove that the span $\infty$-category of $m$-finite spaces is the free $m$-semiadditive $\infty$-category generated by a single object. Passing to presentable ... More

A uniform spectral gap for congruence covers of a hyperbolic manifoldOct 05 2010Nov 16 2010Let $G$ be $\SO(n,1)$ or $\SU(n,1)$ and let $\Gamma\subset G$ denote an arithmetic lattice. The hyperbolic manifold $\Gamma\backslash \calH$ comes with a natural family of covers, coming from the congruence subgroups of $\Gamma$. In many applications, ... More

Shrinking Targets for Semisimple GroupsDec 18 2015May 27 2016We study the shrinking target problem for actions of semisimple groups on homogeneous spaces, with applications to logarithm laws and Diophantine approximation.

The Cobordism Hypothesis in Dimension 1Sep 30 2012In 2009 Lurie published an expository article outlining a proof for a higher version of the cobordism hypothesis conjectured by Baez and Dolan in 1995. In this note we give a proof for the 1-dimensional case of this conjecture. The proof follows most ... More

Lax limits of model categoriesFeb 13 2019For a diagram of simplicial combinatorial model categories, we show that the associated lax limit, endowed with the projective model structure, is a presentation of the lax limit of the underlying $\infty$-categories. Our approach can also allow for the ... More

Crossover behavior of the thermal conductance and Kramers' transition rate theoryDec 19 2013Dec 08 2015Kramers' theory frames chemical reaction rates in solution as reactants overcoming a barrier in the presence of friction and noise. For weak coupling to the solution, the reaction rate is limited by the rate at which the solution can restore equilibrium ... More

On PAC Extensions and Scaled Trace FormsMay 24 2007Aug 29 2007Any non-degenerate quadratic form over a Hilbertian field (e.g., a number field) is isomorphic to a scaled trace form. In this work we extend this result to more general fields. In particular, prosolvable and prime-to-p extensions of a Hilbertian field. ... More

Relaxation times in an open interacting two-qubit systemSep 18 2008In a two-qubit system the coupling with an environment affects considerably the entanglement dynamics, and usually leads to the loss of entanglement within a finite time. Since entanglement is a key feature in the application of such systems to quantum ... More

Fourier's Law: insight from a simple derivationDec 27 2008Feb 04 2009The onset of Fourier's law in a one-dimensional quantum system is addressed via a simple model of weakly coupled quantum systems in contact with thermal baths at their edges. Using analytical arguments we show that the crossover from the ballistic (invalid ... More

Polarization and light curve variability: the "patchy shell" modelOct 08 2003Feb 05 2004Recent advances in early detection and detailed monitoring of GRB afterglows have revealed variability in some afterglow light curves. One of the leading models for this behavior is the patchy shell model. This model attributes the variability to random ... More

On Choptuik's scaling in higher dimensionsFeb 03 2005Jun 06 2005We extend Choptuik's scaling phenomenon found in general relativistic critical gravitational collapse of a massless scalar field to higher dimensions. We find that in the range 4 <= D <= 11 the behavior is qualitatively similar to that discovered by Choptuik. ... More

Zero-Delay and Causal Single-User and Multi-User Lossy Source Coding with Decoder Side InformationJan 01 2013We consider zero-delay single-user and multi-user source coding with average distortion constraint and decoder side information. The zero-delay constraint translates into causal (sequential) encoder and decoder pairs as well as the use of instantaneous ... More

Error Exponents for Broadcast Channels with Degraded Message SetsJun 07 2009We consider a broadcast channel with a degraded message set, in which a single transmitter sends a common message to two receivers and a private message to one of the receivers only. The main goal of this work is to find new lower bounds to the error ... More

On the fibration method for zero-cycles and rational pointsSep 03 2014Jun 22 2015Conjectures on the existence of zero-cycles on arbitrary smooth projective varieties over number fields were proposed by Colliot-Th\'el\`ene, Sansuc, Kato and Saito in the 1980's. We prove that these conjectures are compatible with fibrations, for fibrations ... More

Constructing expander graphs by 2-lifts and discrepancy vs. spectral gapDec 01 2003Apr 08 2004We present a new explicit construction for expander graphs with nearly optimal spectral gap. The construction is based on a series of 2-lift operations. Let $G$ be a graph on $n$ vertices. A 2-lift of $G$ is a graph $H$ on $2n$ vertices, with a covering ... More

Monotone Maps, Sphericity and Bounded Second EigenvalueJan 22 2004We consider {\em monotone} embeddings of a finite metric space into low dimensional normed space. That is, embeddings that respect the order among the distances in the original space. Our main interest is in embeddings into Euclidean spaces. We observe ... More

Conformational Proofreading: The Impact of Conformational Changes on the Specificity of Molecular RecognitionJul 26 2010To perform recognition, molecules must locate and specifically bind their targets within a noisy biochemical environment with many look-alikes. Molecular recognition processes, especially the induced-fit mechanism, are known to involve conformational ... More

Limited-Magnitude Error-Correcting Gray Codes for Rank ModulationJan 20 2016Jun 19 2016We construct Gray codes over permutations for the rank-modulation scheme, which are also capable of correcting errors under the infinity-metric. These errors model limited-magnitude or spike errors, for which only single-error-detecting Gray codes are ... More

Snake-in-the-Box Codes for Rank ModulationJul 18 2011Motivated by the rank-modulation scheme with applications to flash memory, we consider Gray codes capable of detecting a single error, also known as snake-in-the-box codes. We study two error metrics: Kendall's $\tau$-metric, which applies to charge-constrained ... More

Mean dimension and a sharp embedding theorem: extensions of aperiodic subshiftsJul 17 2012We show that if $(X,T)$ is an extension of an aperiodic subshift (a subsystem of $({1,2,...,l}^{\mathbb{Z}},\mathrm{shift})$ for some $l\in\mathbb{N}$) and has mean dimension $mdim(X,T)<\frac{D}{2}$ $(D\in \mathbb{N}$), then it embeds equivariantly in ... More

Minimal hyperspace actions of homeomorphism groups of h-homogeneous spacesJul 07 2011May 07 2012Let X be a h-homogeneous zero-dimensional compact Hausdorff space, i.e. X is a Stone dual of a homogeneous Boolean algebra. Using the dual Ramsey theorem and a detailed combinatorial analysis of what we call stable collections of subsets of a finite set, ... More

Locality in Theory SpaceFeb 24 2012Jun 27 2012Locality is a guiding principle for constructing realistic quantum field theories. Compactified theories offer an interesting context in which to think about locality, since interactions can be nonlocal in the compact directions while still being local ... More

A Character-level Convolutional Neural Network for Distinguishing Similar Languages and DialectsSep 24 2016Discriminating between closely-related language varieties is considered a challenging and important task. This paper describes our submission to the DSL 2016 shared-task, which included two sub-tasks: one on discriminating similar languages and one on ... More

Bitcoin's Security Model RevisitedMay 30 2016May 31 2016We revisit the fundamental question of Bitcoin's security against double spending attacks. While previous work has bounded the probability that a transaction is reversed, we show that no such guarantee can be effectively given if the attacker can choose ... More

RecA-mediated homology search as a nearly optimal signal detection systemNov 19 2010Homologous recombination facilitates the exchange of genetic material between homologous DNA molecules. This crucial process requires detecting a specific homologous DNA sequence within a huge variety of heterologous sequences. The detection is mediated ... More

Singular curves and the etale Brauer-Manin obstruction for surfacesDec 25 2012Nov 22 2013We construct a smooth and projective surface over an arbitrary number field that is a counterexample to the Hasse principle but has the infinite etale Brauer-Manin set. We also construct a surface with a unique rational point and the infinite etale Brauer-Manin ... More

Electron - Dark Matter Scattering in an Evacuated TubeJun 16 2008The light dark matter model can explain both the primordial abundance of dark matter and the anomalous 511 keV gamma-ray signal from the galactic center. This model posits a light neutral scalar, \chi, with a mass in the range 1 MeV < Mchi < 10 MeV, as ... More

Searching for an invisible A' vector boson with DarkLightSep 04 2012Jan 07 2013High-luminosity experiments are able to search for new physics at low energies, which could have evaded detection thus far due to very weak couplings to the Standard Model. The DarkLight experiment at Jefferson Lab is designed to search for a new U(1) ... More

A Juzvinskiĭ Addition Theorem for Finitely Generated Free Groups ActionsOct 23 2011Aug 08 2012The classical Juzvinski\u{i} Addition Theorem states that the entropy of an automorphism of a compact group decomposes along invariant subgroups. Thomas generalized the theorem to a skew-product setting. Using L. Bowen's f-invariant we prove the addition ... More

Embedding minimal dynamical systems into Hilbert cubesNov 05 2015We study the problem of embedding minimal dynamical systems into the shift action on the Hilbert cube $\left([0,1]^N\right)^{\mathbb{Z}}$. This problem is intimately related to the theory of mean dimension, which counts the averaged number of parameters ... More

Optimal Design of a Molecular Recognizer: Molecular Recognition as a Bayesian Signal Detection ProblemJul 26 2010Numerous biological functions-such as enzymatic catalysis, the immune response system, and the DNA-protein regulatory network-rely on the ability of molecules to specifically recognize target molecules within a large pool of similar competitors in a noisy ... More

Unsupervised Learning of Noisy-Or Bayesian NetworksSep 26 2013This paper considers the problem of learning the parameters in Bayesian networks of discrete variables with known structure and hidden variables. Previous approaches in these settings typically use expectation maximization; when the network has high treewidth, ... More

The Grothendieck construction for model categoriesApr 07 2014Jun 12 2015The Grothendieck construction is a classical correspondence between diagrams of categories and coCartesian fibrations over the indexing category. In this paper we consider the analogous correspondence in the setting of model categories. As a main result, ... More

On Real-Time and Causal Secure Source CodingMay 15 2012We investigate two source coding problems with secrecy constraints. In the first problem we consider real--time fully secure transmission of a memoryless source. We show that although classical variable--rate coding is not an option since the lengths ... More

Integer programs with a fixed radius L1-constraint are polynomial-time solvableSep 26 2016Integer programming problems with L1-constraints are ubiquitous. For instance, L1-constraints are found in multidimensional integer packing problems with a capacity constraint. This paper shows that nonlinear integer programs with an L1-constraint can ... More

Integer programs with a fixed radius L1-constraint are polynomial-time solvableSep 26 2016Oct 05 2016Integer programming problems with L1-constraints are ubiquitous. For instance, L1-constraints are found in multidimensional integer packing problems with a capacity constraint. This paper shows that nonlinear integer programs with an L1-constraint can ... More

On the Collapse of Charged Scalar FieldsJun 17 2003We explore numerically the evolution of a collapsing spherical shell of charged, massless scalar field. We obtain an external \RN space-time, and an inner space-time that is bounded by a singularity on the Cauchy Horizon. We compare these results with ... More

Molecular Recognition as an Information Channel: The Role of Conformational ChangesJul 26 2010Molecular recognition, which is essential in processing information in biological systems, takes place in a crowded noisy biochemical environment and requires the recognition of a specific target within a background of various similar competing molecules. ... More

Are stable instances easy?Jun 17 2009We introduce the notion of a stable instance for a discrete optimization problem, and argue that in many practical situations only sufficiently stable instances are of interest. The question then arises whether stable instances of NP--hard problems are ... More

An integral model structure and truncation theory for coherent group actionsJun 12 2015In this work we study the homotopy theory of coherent group actions from a global point of view, where we allow both the group and the space acted upon to vary. Using the model of Segal group actions and the model categorical Grothendieck construction ... More

Zero-Delay and Causal Secure Source CodingNov 19 2013We investigate the combination between causal/zero-delay source coding and information-theoretic secrecy. Two source coding models with secrecy constraints are considered. We start by considering zero-delay perfectly secret lossless transmission of a ... More

Structure Theorems for Real-Time Variable-Rate Coding With and Without Side InformationAug 14 2011The output of a discrete Markov source is to be encoded instantaneously by a variable-rate encoder and decoded by a finite-state decoder. Our performance measure is a linear combination of the distortion and the instantaneous rate. Structure theorems, ... More

Bandits meet Computer Architecture: Designing a Smartly-allocated CacheJan 31 2016In many embedded systems, such as imaging sys- tems, the system has a single designated purpose, and same threads are executed repeatedly. Profiling thread behavior, allows the system to allocate each thread its resources in a way that improves overall ... More

Large-Scale Machine Translation between Arabic and Hebrew: Available Corpora and Initial ResultsSep 25 2016Machine translation between Arabic and Hebrew has so far been limited by a lack of parallel corpora, despite the political and cultural importance of this language pair. Previous work relied on manually-crafted grammars or pivoting via English, both of ... More

On processes which cannot be distinguished by finitary observationAug 13 2006A function $J$ defined on a family $C$ of stationary processes is finitely observable if there is a sequence of functions $s_n$ such that $s_n(x_1 ... x_n)\to J(X)$ in probability for every process $X=(x_n)\in C$. Recently, Ornstein and Weiss roved the ... More

Tunneling into clean Heavy Fermion Compounds: Origin of the Fano LineshapeAug 29 2010Recently observed tunneling spectra on clean heavy fermion compounds show a lattice periodic Fano lineshape similar to what is observed in the case of tunneling to a Kondo ion adsorbed at the surface. We show that the translation symmetry of a clean surface ... More

Local Current Distribution and "Hot Spots" in the Integer Quantum Hall RegimeJul 12 2006Jul 20 2006In a recent experiment, the local current distribution of a two-dimensional electron gas in the quantum Hall regime was probed by measuring the variation of the conductance due to local gating. The main experimental finding was the existence of "hot spots", ... More

Discrete Self-Similarity in Ultra-Relativistic Type-II Strong ExplosionsOct 19 2009A solution to the ultra-relativistic strong explosion problem with a non-power law density gradient is delineated. We consider a blast wave expanding into a density profile falling off as a steep radial power-law with small, spherically symmetric, and ... More

The Étale Homotopy Type and Obstructions to the Local-Global PrincipleFeb 07 2010Nov 30 2011In 1969 Artin and Mazur defined the \'etale homotopy type of an algebraic variety \cite{AMa69}. In this paper we define various obstructions to the local-global principle on a variety $X$ over a global field using the \'etale homotopy type of $X$ and ... More

Homotopy Obstructions to Rational PointsOct 02 2011In this paper we propose to use a relative variant of the notion of the \'{e}tale homotopy type of an algebraic variety in order to study the existence of rational points on it. In particular, we use an appropriate notion of homotopy fixed points in order ... More

Time-reversal in dynamically-tuned zero-gap periodic systemsApr 24 2011We show that short pulses propagating in zero-gap periodic systems can be reversed with 100% efficiency by using weak non-adiabatic tuning of the wave velocity at time-scales that can be much slower than the period. Unlike previous schemes, we demonstrate ... More

Discrete Self-Similarity in Type-II Strong ExplosionsJul 10 2009We present new solutions to the strong explosion problem in a non-power law density profile. The unperturbed self-similar solutions discovered by Waxman & Shvarts describe strong Newtonian shocks propagating into a cold gas with a density profile falling ... More

Hasse principle for generalised Kummer varietiesApr 09 2015The existence of rational points on Kummer varieties associated to 2-coverings of abelian varieties over number fields can sometimes be proved through the variation of the Selmer group in the family of quadratic twists of the underlying abelian variety, ... More

Minimizing the Maximal Loss: How and Why?Feb 04 2016May 22 2016A commonly used learning rule is to approximately minimize the \emph{average} loss over the training set. Other learning algorithms, such as AdaBoost and hard-SVM, aim at minimizing the \emph{maximal} loss over the training set. The average loss is more ... More