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A group theoretical approach to computing phonons and their interactionsApr 12 2019Here we present four independent advances which facilitate the computation of phonons and their interactions from first-principles. First, we implement a group-theoretical approach to construct the order N Taylor series of a d-dimensional crystal purely ... More

Origin of Spinel Nanocheckerboards via First PrinciplesJan 14 2015Self-organizing nanocheckerboards have been experimentally fabricated in Mn-based spinels, but have not yet been explained with first principles. Using density-functional-theory, we explain the phase diagram of the $\mathrm{ZnMn_xGa_{2-x}O_4}$ system ... More

New Supercoherent StatesMar 04 2012This study generalizes the supersymmetric coherent states introduced by Aragone and Zypman in 1986. The Hamiltonian of the supersymmetric quantum harmonic oscillator leads to the definition of the generalized supersymmetric annihilation operators as a ... More

An example of an infinite set of associated primes of a local cohomology moduleSep 25 2002Let $(R,m)$ be a local Noetherian ring, let $I\subset R$ be any ideal and let $M$ be a finitely generated $R$-module. In 1990 Craig Huneke conjectured that the local cohomology modules $H^i_I(M)$ have finitely many associated primes for all $i$. In this ... More

A non-finitely generated algebra of Frobenius mapsJun 05 2009Dec 14 2009The purpose of this paper is to answer a question raised by Gennady Lyubeznik and Karen Smith. This question involves the finite generation of the following non-commutative algebra. Let $S$ be any commutative algebra of prime characteristic $p$. For any ... More

$F$-stable submodules of top local cohomology modules of Gorenstein ringsFeb 24 2006This paper applies G. Lyubeznik's notion of $F$-finite modules to describe in a very down-to-earth manner certain annihilator submodules of some top local cohomology modules over Gorenstein rings. As a consequence we obtain an explicit description of ... More

Finiteness of $\bold{\bigcup_e \Ass F^e(M)}$ and its connections to tight closureSep 25 2002Sep 26 2002The paper shows that if the set of associated primes of Frobenius powers of ideals or a closely related set of primes is finite then if tight closure does not commute with localisation one can find a counter-example where $R$ is complete local and we ... More

Parameter test ideals of Cohen Macaulay ringsJan 21 2007Nov 26 2007We describe an algorithm for computing parameter-test-ideals in certain local Cohen-Macaulay rings. The algorithm is based on the study of a Frobenius map on the injective hull of the residue field of the ring and on the application of Rodney Sharp's ... More

Characteristic-independence of Betti numbers of graph idealsAug 02 2004Apr 07 2005In this paper we study the Betti numbers of Stanley-Reisner ideals generated in degree 2. We show that the first six Betti numbers do not depend on the characteristic of the ground field. We also show that, if the number of variables $n$ is at most 10, ... More

On ideals of minors of matrices with indeterminate entriesSep 28 2005Oct 06 2005This paper has two aims. The first is to study ideals of minors of matrices whose entries are among the variables of a polynomial ring. Specifically, we describe matrices whose ideals of minors of a given size are prime. The main result in the first part ... More

Counting monomialsApr 06 2005This paper presents two enumeration techniques based on Hilbert functions. The paper illustrates these techniques by solving two chessboard problems.

The Hilbert series of algebras of Veronese typeAug 03 2004This paper gives a fairly explicit formula for the Hilbert series of algebras of Veronese type.

Some properties and applications of $F$-finite $F$-modulesSep 14 2010Feb 03 2011The purpose of this paper is to describe several applications of finiteness properties of $F$-finite $F$-modules recently discovered by M. Hochster to the study of Frobenius maps on injective hulls, Frobenius near-splittings and to the nature of morphisms ... More

Optimization and Reoptimization in Scheduling ProblemsSep 04 2015Parallel machine scheduling has been extensively studied in the past decades, with applications ranging from production planning to job processing in large computing clusters. In this work we study some of these fundamental optimization problems, as well ... More

Frobenius maps on injective hulls and their applications to tight closureFeb 18 2009Nov 27 2009This paper studies Frobenius maps on injective hulls of residue fields of complete local rings with a view toward providing constructive descriptions of objects originating from the theory of tight closure. Specifically, the paper describes algorithms ... More

Bipartite graphs whose edge algebras are complete intersectionsSep 25 2002Let R be monomial sub-algebra of $k[x_1,...,x_N]$ generated by square free monomials of degree two. This paper addresses the following question: when is R a complete intersection? For such a k-algebra we can associate a graph G whose vertices are $x_1,...,x_N$ ... More

Cascading Failures in Networks with Proximate Dependent NodesOct 21 2013We study the mutual percolation of a system composed of two interdependent random regular networks. We introduce a notion of distance to explore the effects of the proximity of interdependent nodes on the cascade of failures after an initial attack. We ... More

Multiplicity bounds in prime characteristicApr 30 2018Aug 12 2018We extend a result by Huneke and Watanabe bounding the multiplicity of $F$-pure local rings of prime characteristic in terms of their dimension and embedding dimensions to the case of $F$-injective, generalized Cohen-Macaulay rings. We then produce an ... More

Sub-Wavelength Nonlinear Accelerating BeamsApr 26 2012We show that optical nonlinearities allow sub-wavelength beams to propagate in circular trajectories without being attenuated in spite of their partially evanescent spectrum. Such beams are exact solutions to Maxwell's equations with Kerr or saturable ... More

Edge Coloring with Minimum Reload/Changeover CostsJul 22 2016In an edge-colored graph, a traversal cost occurs at a vertex along a path when consecutive edges with different colors are traversed. The value of the traversal cost depends only on the colors of the traversed edges. This concept leads to two global ... More

The support of local cohomology modulesSep 04 2015May 04 2017We describe the support of $F$-finite $F$-modules over polynomial rings $R$ of prime characteristic. Our description yields an algorithm to compute the support of such modules; the complexity of our algorithm is also analyzed. To the best of our knowledge, ... More

The Betti numbers of forestsJan 14 2005Feb 17 2005This paper produces a recursive formula of the Betti numbers of certain Stanley-Reisner ideals (graph ideals associated to forests). This gives a purely combinatorial definition of the projective dimension of these ideals, which turns out to be a new ... More

The support of local cohomology modulesSep 04 2015Jun 21 2016We describe the support of $F$-finite $F$-modules over a polynomial ring $R$ of prime characteristic. Our description yields an algorithm to compute the support of such local cohomology modules of $R$; the complexity of our algorithm is also analyzed. ... More

An algorithm for computing compatibly Frobenius split subvarietiesApr 11 2011Feb 13 2012Let $R$ be a ring of prime characteristic $p$, and let $F^e_* R$ denote $R$ viewed as an $R$-module via the $e$th iterated Frobenius map. Given a surjective map $\phi : F^e_* R \to R$ (for example a Frobenius splitting), we exhibit an algorithm which ... More

On the arithmetic of tight closureDec 01 2004Dec 02 2004We provide a negative answer to an old question in tight closure theory by showing that the containment x^3y^3 \in (x^4,y^4,z^4)^* in K[x,y,z]/(x^7+y^7-z^7) holds for infinitely many but not for almost all prime characteristics of the field K. This proves ... More

Castelnuovo-Mumford regularity and the discreteness of $F$-jumping coefficients in graded ringsOct 10 2011Jul 12 2012In this paper we show that the sets of $F$-jumping coefficients of ideals form discrete sets in certain graded $F$-finite rings. We do so by giving a criterion based on linear bounds for the growth of the Castelnuovo-Mumford regularity of certain ideals. ... More

Annihilators of Artinian modules compatible with a Frobenius mapJan 08 2013Oct 18 2013In this paper we consider Artinian modules over power series rings endowed with a Frobenius map. We describe a method for finding the set of all prime annihilators of submodules which are preserved by the given Frobenius map and on which the Frobenius ... More

$G/G$--Topological Field Theories by Cosetting $G_k$Jan 19 1992$G/G$ topological field theories based on $G_k$ WZW models are constructed and studied. These coset models are formulated as Complex BRST cohomology in $G^c_k$, the complexified level $k$ current algebra. The finite physical spectrum corresponds to the ... More

Nonlinear wave dynamics in honeycomb latticesMay 23 2011We study the nonlinear dynamics of wave packets in honeycomb lattices, and show that, in quasi-1D configurations, the waves propagating in the lattice can be separated into left-moving and right-moving waves, and any wave packet composed of left (or right) ... More

Uniform Behaviour of the Frobenius closures of ideals generated by regular sequencesJan 28 2005This paper is concerned with ideals in a commutative Noetherian ring $R$ of prime characteristic. The main purpose is to show that the Frobenius closures of certain ideals of $R$ generated by regular sequences exhibit a desirable type of `uniform' behaviour. ... More

Some properties of top graded local cohomology modulesSep 25 2002This first part of the paper describes the support of top graded local cohomology modules. As a corrolary one obtains a simple criteria for the vanishing of these modules and also the fact that they have finitely many minimal primes. The second part of ... More

An algorithm for producing F-pure idealsJul 25 2013Oct 23 2014This paper describes a method for computing all F-pure ideals for a given Cartier map of a polynomial ring over a finite field.

Tighter Bounds for Makespan Minimization on Unrelated MachinesMay 11 2014Jun 23 2014We consider the problem of scheduling $n$ jobs to minimize the makespan on $m$ unrelated machines, where job $j$ requires time $p_{ij}$ if processed on machine $i$. A classic algorithm of Lenstra et al. yields the best known approximation ratio of $2$ ... More

Self-trapping of Necklace beams in Self-focusing Kerr mediaOct 13 1998Nov 17 1998We show that an azimuthally-periodically-modulated bright ring "necklace" beam can self-trap in self-focusing Kerr media and can exhibit stable propagation for very large distances. These are the first bright (2+1) D beams to exhibit stable self-trapping ... More

An upper bound on the number of F-jumping coefficients of a principal idealOct 10 2010We prove a result relating the Jacobian ideal and the generalized test ideal associated to a principal ideal in $R=k[x_1,...,x_n]$ with $[k:k^p]<\infty$ or in $R=k[[x_1,...,x_n]]$ with an arbitrary field $k$ of characteristic $p>0$. As a consequence of ... More

USBee: Air-Gap Covert-Channel via Electromagnetic Emission from USBAug 30 2016In recent years researchers have demonstrated how attackers could use USB connectors implanted with RF transmitters to exfiltrate data from secure, and even air-gapped, computers (e.g., COTTONMOUTH in the leaked NSA ANT catalog). Such methods require ... More

9-1-1 DDoS: Threat, Analysis and MitigationSep 08 2016The 911 emergency service belongs to one of the 16 critical infrastructure sectors in the United States. Distributed denial of service (DDoS) attacks launched from a mobile phone botnet pose a significant threat to the availability of this vital service. ... More

The Complexity of Subtree Intersection Representation of Chordal Graphs and Linear Time Chordal Graph GenerationApr 09 2019It is known that any chordal graph on $n$ vertices can be represented as the intersection of $n$ subtrees in a tree on $n$ nodes. This fact is recently used in [2] to generate random chordal graphs on $n$ vertices by generating $n$ subtrees of a tree ... More

Onion-peeling inversion of stellarator imagesJun 10 2016Jul 12 2016An onion-peeling technique is developed for inferring the emissivity profile of a stellarator plasma from a two-dimensional image acquired through a CCD or CMOS camera. Each pixel in the image is treated as an integral of emission along a particular line-of-sight. ... More

On the discreteness and rationality of F-jumping coefficientsJun 20 2007Jan 30 2008This paper studies the jumping coefficients of principal ideals of regular local rings. Recently M. Blickle, M. Mustata and K. Smith showed that, when $R$ is of essentially finite type over a field and $F$-finite, bounded intervals contain finitely many ... More

Strong $F$-regularity and generating morphisms of local cohomology modulesJun 12 2018We establish a criterion for the strong $F$-regularity of a (non-Gorenstein) Cohen-Macaulay reduced complete local ring of dimension at least $2$, containing a perfect field of prime characteristic $p$. We also describe an explicit generating morphism ... More

The Maximum Cut Problem in Co-bipartite Chain GraphsApr 14 2015A \emph{co-bipartite chain} graph is a co-bipartite graph in which the neighborhoods of the vertices in each clique can be linearly ordered with respect to inclusion. It is known that the maximum cut problem (MaxCut) is NP-Hard in co-bipartite graphs. ... More

The Maximum Cardinality Cut Problem is Polynomial in Proper Interval GraphsDec 21 2015It is known that the maximum cardinality cut problem is NP-hard even in chordal graphs. In this paper, we consider the time complexity of the problem in proper interval graphs, a subclass of chordal graphs, and propose a dynamic programming algorithm ... More

Topology of photonic time-crystalsMar 23 2018We introduce topological phases in Photonic Time-Crystals. Photonic Time-Crystals are materials in which the refractive index varies periodically and abruptly in time. When the refractive index changes abruptly, the light propagating in the material experiences ... More

MAGNETO: Covert Channel between Air-Gapped Systems and Nearby Smartphones via CPU-Generated Magnetic FieldsFeb 07 2018In this paper, we show that attackers can leak data from isolated, air-gapped computers to nearby smartphones via covert magnetic signals. The proposed covert channel works even if a smartphone is kept inside a Faraday shielding case, which aims to block ... More

Two interesting examples of $\mathcal{D}$-modules in characteristic $p>0$Oct 12 2010We provide two examples of $\mathcal{D}$-modules in prime characteristic $p$ which answer two open problems in \cite{Lyubeznik} in the negative.

An extension of a theorem of HartshorneAug 05 2014Oct 08 2014We extend a classical theorem of Hartshorne concerning the connectedness of the punctured spectrum of a local ring by analyzing the homology groups of a simplicial complex associated with the minimal primes of a local ring.

Proto-CIRCUS Tilted-Coil Tokamak-Torsatron Hybrid: Design and ConstructionOct 08 2014We present the field-line modeling, design and construction of a prototype circular-coil tokamak-torsatron hybrid called Proto-CIRCUS. The device has a major radius R = 16 cm and minor radius a < 5 cm. The six "toroidal field" coils are planar as in a ... More

Global parameter test idealsJul 07 2016This paper shows the existence of ideals whose localizations and completions at prime ideals are parameter test ideals of the localized and completed rings. We do this for Cohen-Macaulay localizations (resp., completions) of non-local rings, for generalized ... More

Personal Information Leakage During Password Recovery of Internet ServicesAug 04 2016In this paper we examine the standard password recovery process of large Internet services such as Gmail, Facebook, and Twitter. Although most of these services try to maintain user privacy, with regard to registration information and other personal information ... More

Fansmitter: Acoustic Data Exfiltration from (Speakerless) Air-Gapped ComputersJun 19 2016Because computers may contain or interact with sensitive information, they are often air-gapped and in this way kept isolated and disconnected from the Internet. In recent years the ability of malware to communicate over an air-gap by transmitting sonic ... More

DiskFiltration: Data Exfiltration from Speakerless Air-Gapped Computers via Covert Hard Drive NoiseAug 11 2016Air-gapped computers are disconnected from the Internet physically and logically. This measure is taken in order to prevent the leakage of sensitive data from secured networks. In the past, it has been shown that malware can exfiltrate data from air-gapped ... More

Solitonic GluonsAug 19 1998We describe a physical mechanism for creating multi-soliton bound states where solitons are glued together by attraction between the beams they guide, `solitonic gluons'. We verify the concept of the solitonic gluons experimentally, observing a suppression ... More

ODINI : Escaping Sensitive Data from Faraday-Caged, Air-Gapped Computers via Magnetic FieldsFeb 08 2018Air-gapped computers are computers which are kept isolated from the Internet, because they store and process sensitive information. When highly sensitive data is involved, an air-gapped computer might also be kept secluded in a Faraday cage. The Faraday ... More

Breakdown of Dirac Dynamics in Honeycomb Lattices due to Nonlinear InteractionsApr 12 2010Apr 27 2010We study the dynamics of coherent waves in nonlinear honeycomb lattices and show that nonlinearity breaks down the Dirac dynamics. As an example, we demonstrate that even a weak nonlinearity has major qualitative effects one of the hallmarks of honeycomb ... More

Graphs of Edge-Intersecting Non-Splitting Paths in a Tree: Representations of Holes-Part IISep 25 2013Jan 09 2018Given a tree and a set P of non-trivial simple paths on it, VPT(P) is the VPT graph (i.e. the vertex intersection graph) of the paths P, and EPT(P) is the EPT graph (i.e. the edge intersection graph) of P. These graphs have been extensively studied in ... More

Equimatchable Claw-Free GraphsJul 02 2016Jul 24 2018A graph is equimatchable if all of its maximal matchings have the same size. A graph is claw-free if it does not have a claw as an induced subgraph. In this paper, we provide, to the best of our knowledge, the first characterization of claw-free equimatchable ... More

Hierarchical b-MatchingApr 23 2019A matching of a graph is a subset of edges no two of which share a common vertex, and a maximum matching is a matching of maximum cardinality. In a $b$-matching every vertex $v$ has an associated bound $b_v$, and a maximum $b$-matching is a maximum set ... More

Doping Human Serum Albumin with Retinoate Markedly Enhances Electron Transport Across the ProteinJul 22 2012Electrons can migrate via proteins over distances that are considered long for non-conjugated systems. Proteins' nano-scale dimensions and the enormous flexibility of their structures and chemistry makes them fascinating subjects for investigating the ... More

BitWhisper: Covert Signaling Channel between Air-Gapped Computers using Thermal ManipulationsMar 26 2015It has been assumed that the physical separation (air-gap) of computers provides a reliable level of security, such that should two adjacent computers become compromised, the covert exchange of data between them would be impossible. In this paper, we ... More

Equimatchable Claw-Free GraphsJul 02 2016Jul 10 2016A graph is equimatchable if all of its maximal matchings have the same size. A graph is claw-free if it does not have a claw as an induced subgraph. In this paper, we provide, to the best of our knowledge, the first characterization of claw-free equimatchable ... More

Graphs of Edge-Intersecting and Non-Splitting One Bend Paths in a GridDec 20 2015Sep 14 2016The families EPT (resp. EPG) Edge Intersection Graphs of Paths in a tree (resp. in a grid) are well studied graph classes. Recently we introduced the graph classes Edge-Intersecting and Non-Splitting Paths in a Tree ENPT, and in a Grid (ENPG). It was ... More

PT-symmetry in honeycomb photonic latticesMar 17 2011Apr 20 2011We apply gain/loss to honeycomb photonic lattices and show that the dispersion relation is identical to tachyons - particles with imaginary mass that travel faster than the speed of light. This is accompanied by PT-symmetry breaking in this structure. ... More

PowerHammer: Exfiltrating Data from Air-Gapped Computers through Power LinesApr 10 2018In this paper we provide an implementation, evaluation, and analysis of PowerHammer, a malware (bridgeware [1]) that uses power lines to exfiltrate data from air-gapped computers. In this case, a malicious code running on a compromised computer can control ... More

Frobenius test exponents for parameter ideals in generalized Cohen-Macaulay local ringsJul 06 2006This paper studies Frobenius powers of parameter ideals in a commutative Noetherian local ring $R$ of prime characteristic $p$. For a given ideal $\fa$ of $R$, there is a power $Q$ of $p$, depending on $\fa$, such that the $Q$-th Frobenius power of the ... More

Parameterized complexity of the MINCCA problem on graphs of bounded decomposabilityMay 02 2016In an edge-colored graph, the cost incurred at a vertex on a path when two incident edges with different colors are traversed is called reload or changeover cost. The "Minimum Changeover Cost Arborescence" (MINCCA) problem consists in finding an arborescence ... More

VisiSploit: An Optical Covert-Channel to Leak Data through an Air-GapJul 13 2016Jul 19 2016In recent years, various out-of-band covert channels have been proposed that demonstrate the feasibility of leaking data out of computers without the need for network connectivity. The methods proposed have been based on different type of electromagnetic, ... More

AirHopper: Bridging the Air-Gap between Isolated Networks and Mobile Phones using Radio FrequenciesNov 02 2014Information is the most critical asset of modern organizations, and accordingly coveted by adversaries. When highly sensitive data is involved, an organization may resort to air-gap isolation, in which there is no networking connection between the inner ... More

Enhanced transport when Anderson localization is destroyedOct 13 2011Jun 03 2012We investigate the anomalous transport in optically-induced potentials that are random in both space and time. We find that the time variation destroys Anderson localization, replacing it by transport that is faster than diffusion, which in some cases ... More

Graphs of Edge-Intersecting Non-Splitting Paths in a Tree: Representations of Holes-Part IISep 25 2013Aug 09 2016Given a tree and a set P of non-trivial simple paths on it, VPT(P) is the VPT graph (i.e. the vertex intersection graph) of the paths P, and EPT(P) is the EPT graph (i.e. the edge intersection graph) of P. These graphs have been extensively studied in ... More

Graphs of Edge-Intersecting Non-Splitting Paths in a Tree: Towards Hole Representations-Part ISep 11 2013Jul 09 2015Given a tree and a set ${\cal P}$ of non-trivial simple paths on it, $VPT({\cal P})$ is the VPT graph (i.e. the vertex intersection graph) of the paths ${\cal P}$ of the tree $T$, and $EPT({\cal P})$ is the EPT graph (i.e. the edge intersection graph) ... More

Graphs of Edge-Intersecting and Non-Splitting One Bend Paths in a GridDec 20 2015Jun 09 2017The families EPT (resp. EPG) Edge Intersection Graphs of Paths in a tree (resp. in a grid) are well studied graph classes. Recently we introduced the graph classes Edge-Intersecting and Non-Splitting Paths in a Tree ENPT, and in a Grid (ENPG). It was ... More

Topological Photonic Quasicrystals: Fractal Topological Spectrum and Protected TransportMay 25 2017We show that it is possible to have a topological phase in two-dimensional quasicrystals without any magnetic field applied, but instead introducing an artificial gauge field via dynamic modulation. This topological quasicrystal exhibits scatter-free ... More

Three-dimensional Accelerating Electromagnetic WavesMar 25 2013We present a general theory of three-dimensional nonparaxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification ... More

Associated primes of graded components of local cohomology modulesSep 25 2002The $i$-th local cohomology module of a finitely generated graded module $M$ over a standard positively graded commutative Noetherian ring $R$, with respect to the irrelevant ideal $R_+$, is itself graded; all its graded components are finitely generated ... More

A Simple Extension of Dirac's Theorem on HamiltonicityJun 12 2016The classical Dirac theorem asserts that every graph $G$ on $n$ vertices with minimum degree $\delta(G) \ge \lceil n/2 \rceil$ is Hamiltonian. The lower bound of $\lceil n/2 \rceil$ on the minimum degree of a graph is tight. In this paper, we extend the ... More

Rings of Frobenius operatorsApr 23 2013Let R be a local ring of prime characteristic. We study the ring of Frobenius operators F(E), where E is the injective hull of the residue field of R. In particular, we examine the finite generation of F(E) over its degree zero component, and show that ... More

Designing and using prior data in Ankylography: Recovering a 3D object from a single diffraction intensity patternMar 08 2012We present a novel method for Ankylography: three-dimensional structure reconstruction from a single shot diffraction intensity pattern. Our approach allows reconstruction of objects containing many more details than was ever demonstrated, in a faster ... More

Non-Paraxial Accelerating BeamsDec 31 2011Feb 03 2012We present the spatially accelerating solutions of the Maxwell equations. Such non-paraxial beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams. For both TE and TM polarizations, the beams exhibit shape-preserving bending ... More

Non-Diffracting Electron Vortex Beams Balancing Their Electron-Electron InteractionsSep 25 2015Jul 26 2016By introducing concepts of beam shaping into quantum mechanics, we show how interference effects of the quantum wavefunction describing multiple electrons can exactly balance the repulsion among the electrons. With proper shaping of the fermionic wavefunction, ... More

Shape-Preserving Accelerating Electromagnetic Wavepackets in Curved SpaceOct 23 2013We present shape-preserving spatially accelerating electromagnetic wavepackets in curved space: wavepackets propagating along non-geodesic trajectories while recovering their structure periodically. These wavepackets are solutions to the paraxial and ... More

JoKER: Trusted Detection of Kernel Rootkits in Android Devices via JTAG InterfaceDec 13 2015Smartphones and tablets have become prime targets for malware, due to the valuable private and corporate information they hold. While Anti-Virus (AV) program may successfully detect malicious applications (apps), they remain ineffective against low-level ... More

Sparsity based sub-wavelength imaging with partially incoherent light via quadratic compressed sensingApr 22 2011We demonstrate that sub-wavelength optical images borne on partially-spatially-incoherent light can be recovered, from their far-field or from the blurred image, given the prior knowledge that the image is sparse, and only that. The reconstruction method ... More

Observation of Accelerating Wave Packets in Curved SpaceMar 23 2018We present the first experimental observation of accelerating beams in curved space. More specifically, we demonstrate, experimentally and theoretically, shape-preserving accelerating beams propagating on spherical surfaces: closed-form solutions of the ... More

Depth in classical Coexter groupsJul 05 2015The depth statistic was defined by Petersen and Tenner for an element of an arbitrary Coxeter group in terms of factorizations of the element into a product of reflections. It can also be defined as the minimal cost, given certain prescribed edge weights, ... More

Deep Learning Reconstruction of Ultra-Short PulsesMar 15 2018Ultra-short laser pulses with femtosecond to attosecond pulse duration are the shortest systematic events humans can create. Characterization (amplitude and phase) of these pulses is a key ingredient in ultrafast science, e.g., exploring chemical reactions ... More

Super-Resolution and Reconstruction of Sparse Sub-Wavelength ImagesNov 05 2009We use compressed sensing to demonstrate theoretically the reconstruction of sub-wavelength features from measured far-field, and provide experimental proof-of-concept. The methods can be applied to non-optical microscopes, provided the information is ... More

Super-diffusion in optical realizations of Anderson localizationMar 05 2012We discuss the dynamics of particles in one dimension in potentials that are random both in space and in time. The results are applied to recent optics experiments on Anderson localization, in which the transverse spreading of a beam is suppressed by ... More

$D$-module and $F$-module length of local cohomology modulesSep 06 2016Sep 20 2016Let $R$ be a polynomial or power series ring over a field $k$. We study the length of local cohomology modules $H^j_I(R)$ in the category of $D$-modules and $F$-modules. We show that the $D$-module length of $H^j_I(R)$ is bounded by a polynomial in the ... More

SPEAKE(a)R: Turn Speakers to Microphones for Fun and ProfitNov 22 2016It is possible to manipulate the headphones (or earphones) connected to a computer, silently turning them into a pair of eavesdropping microphones - with software alone. The same is also true for some types of loudspeakers. This paper focuses on this ... More

xLED: Covert Data Exfiltration from Air-Gapped Networks via Router LEDsJun 04 2017In this paper we show how attackers can covertly leak data (e.g., encryption keys, passwords and files) from highly secure or air-gapped networks via the row of status LEDs that exists in networking equipment such as LAN switches and routers. Although ... More

Global parameter test idealsJul 07 2016May 08 2017This paper shows the existence of ideals whose localizations and completions at prime ideals are parameter test ideals of the localized and completed rings. We do this for Cohen-Macaulay localizations (resp., completions) of non-local rings, for generalized ... More

LED-it-GO: Leaking (a lot of) Data from Air-Gapped Computers via the (small) Hard Drive LEDFeb 22 2017In this paper we present a method which allows attackers to covertly leak data from isolated, air-gapped computers. Our method utilizes the hard disk drive (HDD) activity LED which exists in most of today's desktop PCs, laptops and servers. We show that ... More

Minimum Reload Cost Graph FactorsOct 27 2018Feb 06 2019The concept of Reload cost in a graph refers to the cost that occurs while traversing a vertex via two of its incident edges. This cost is uniquely determined by the colors of the two edges. This concept has various applications in transportation networks, ... More

Maximizing Communication Throughput in Tree NetworksApr 23 2019A widely studied problem in communication networks is that of finding the maximum number of communication requests that can be concurrently scheduled, provided that there are at most $k$ requests that pass through any given edge of the network. In this ... More

Airy beams and accelerating waves: An overview of recent advancesApr 05 2019Over the last dozen of years, the area of accelerating waves has made considerable advances not only in terms of fundamentals and experimental demonstrations but also in connection to a wide range of applications. Starting from the prototypical Airy beam ... More

Observation of 2nd band vortex solitons in 2D photonic latticesMar 14 2005We demonstrate second-band bright vortex-array solitons in photonic lattices. This constitutes the first experimental observation of higher-band solitons in any 2D periodic system. These solitons possess complex intensity and phase structures, yet they ... More

Modulation Instability and Pattern Formation in Spatially Incoherent Light BeamsMay 31 2000We present the first experimental observation of modulation instability of partially spatially incoherent light beams in non-instantaneous nonlinear media. We show that even in such a nonlinear partially coherent system (of weakly-correlated particles) ... More

Structure-Based Super-Resolution Recovery of Three-Photon Quantum States from Two-Fold CoincidencesNov 09 2014The field of quantum information has been growing fast over the past decade. Optical quantum computation, based on the concepts of KLM and cluster states, has witnessed experimental realizations of larger and more complex systems in terms of photon number. ... More

Temperature and force dependence of nanoscale electron transport via the Cu protein AzurinJul 22 2012Sep 14 2012The mechanisms of solid-state electron transport (ETp) via a monolayer of immobilized Azurin (Az) was examined by conducting probe atomic force microscopy (CP-AFM), both as function of temperature (248 - 373K) and of applied tip force (6-12 nN). By varying ... More