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Negative longitudinal magnetoresistance in the density wave phase of Y$_2$Ir$_2$O$_7$Feb 08 2018The ground state of nanowires of single crystalline Pyrochlore Y$_2$Ir$_2$O$_7$ is a density wave. Application of a {\it transverse} magnetic field increases the threshold electric field for the collective de-pinning of the density wave state at low temperature, ... More

Colossal enhancement of electrical conductivity in Y2Ir2O7 nanoparticlesNov 17 2016We present a comparative study of the magnetic and electrical properties of polycrystalline and nanocrystalline Y2Ir2O7, the latter prepared using a new chemical route. We find that reduction in particle size leads to enhanced ferromagnetism and orders ... More

Thermodynamics of Quantum Isolated Horizons with model HamiltoniansMar 20 2013Jul 17 2014Following a recent proposal, we consider the most general structure possible for the Hamiltonian operator associated with the Quantum Isolated Horizon(QIH) with explanations of the underlying physical motivations. An extensive thermodynamic analysis with ... More

Proof of Bekenstein-Mukhanov ansatz in loop quantum gravitySep 22 2016A simple proof of Bekenstein-Mukhanov(BM) ansatz is given within the loop quantum gravity(LQG) framework. The macroscopic area of an equilibrium black hole horizon indeed manifests a linear quantization. The quantum number responsible for this discreteness ... More

Black Hole Entropy from indistinguishable quantum geometric excitationsFeb 06 2014Nov 21 2015In loop quantum gravity, the quantum geometry of a black hole horizon consist of discrete non-perturbative quantum geometric excitations (or punctures) labeled by spins, which are responsible for the quantum area of the horizon. If these punctures are ... More

Comment on `Black hole entropy and isolated horizon thermodynamics'Apr 12 2012Nov 04 2013There is a deep underlying problem in the model dependent thermodynamic analysis of black holes shown in the above quoted paper. In this method one can only find out the canonical entropy of the black hole but not the `microcanonical' entropy. Besides ... More

Improvised Salient Object Detection and ManipulationNov 10 2015In case of salient subject recognition, computer algorithms have been heavily relied on scanning of images from top-left to bottom-right systematically and apply brute-force when attempting to locate objects of interest. Thus, the process turns out to ... More

Optimal Morse functions and $H(\mathcal{M}^2,\mathbb{A})$ in $\tilde{O}(N)$ timeMay 09 2015In this work, we design a nearly linear time discrete Morse theory based algorithm for computing homology groups of 2-manifolds, thereby establishing the fact that computing homology groups of 2-manifolds is remarkably easy. Unlike previous algorithms ... More

Heat transport in disordered quantum harmonic oscillator chainsOct 21 2002Jan 21 2003We study heat conduction in quantum disordered harmonic chains connected to general heat reservoirs which are modeled as infinite collection of oscillators. Formal exact expressions for the thermal current are obtained and it is shown that, in some special ... More

Comment on ``A simple one-dimensional model of heat conduction which obeys Fourier's law''Mar 05 2002A finite Green-Kubo thermal conductivity in a one-dimensional momentum conserving system was reported recently by Garrido et al [Phys. Rev. Lett., vol. 86, 5486 (2001)]. We first comment on the apparent contradiction with an earlier result of Prosen and ... More

The $q$-analog of higher order Hochschild homology and the Lie derivativeNov 03 2014Let $A$ be a commutative algebra over $\mathbb C$. Given a pointed simplicial finite set $Y$ and $q\in \mathbb C$ a primitive $N$-th root of unity, we define the $q$-Hochschild homology groups of $A$ of order $Y$. When $D$ is a derivation on $A$, we construct ... More

On Noetherian schemes over $(\mathcal C,\otimes,1)$ and the category of quasi-coherent sheavesMay 06 2015Jan 05 2016Let $(\mathcal C,\otimes,1)$ be an abelian symmetric monoidal category satisfying certain conditions and let $X$ be a scheme over $(\mathcal C,\otimes,1)$ in the sense of To\"en and Vaqui\'{e}. In this paper we show that when $X$ is quasi-compact and ... More

Pullbacks of Eisenstein series from GU(3,3) and critical L-values for GSp(4) X GL(2)Apr 25 2009Oct 02 2009Let F be a genus two Siegel newform and g a classical newform, both of squarefree levels and of equal weight l. We prove a pullback formula for certain Eisenstein series -- thus generalizing a construction of Shimura -- and use this to derive an explicit ... More

Quasimodular Hecke algebras and Hopf actionsNov 12 2014Sep 03 2015Let $\Gamma=\Gamma(N)$ be a principal congruence subgroup of $SL_2(\mathbb Z)$. In this paper, we extend the theory of modular Hecke algebras due to Connes and Moscovici to define the algebra $\mathcal Q(\Gamma)$ of quasimodular Hecke operators of level ... More

On some spectral spaces associated to tensor triangulated categoriesOct 26 2016We consider a closure operator $c$ of finite type on the space $SMod(\mathcal M)$ of thick $\mathcal K$-submodules of a triangulated category $\mathcal M$ that is a module over a tensor triangulated category $(\mathcal K,\otimes,1)$. Our purpose is to ... More

Conformal blocks on a 2-sphere with indistinguishable punctures and implications on black hole entropySep 04 2016Oct 06 2016The dimensionality of the Hilbert space of a Chern-Simons theory on a 3-fold, in the presence of Wilson lines carrying spin representations, had been counted by using its link with the Wess-Zumino theory, with level $k$, on the 2-sphere with points (to ... More

Stability of Quantum Isolated Horizon : A Local Observer's ViewDec 15 2011Feb 28 2013It is shown that a Quantum Isolated Horizon(QIH), as observed by a local observer, is locally unstable as a thermodynamic system. The result is derived in two different ways. Firstly, the specific heat of the QIH is shown to be negative definite through ... More

Twitter and Polls: Analyzing and estimating political orientation of Twitter users in India General #Elections2014Jun 19 2014This year (2014) in the month of May, the tenure of the 15th Lok Sabha was to end and the elections to the 543 parliamentary seats were to be held. A whooping $5 billion were spent on these elections, which made us stand second only to the US Presidential ... More

Mass Deformations of Super Yang-Mills Theories in D= 2+1, and Super-Membranes: A NoteJun 26 2008Mass deformations of supersymmetric Yang-Mills theories in three spacetime dimensions are considered. The gluons of the theories are made massive by the inclusion of a non-local gauge and Poincare invariant mass term due to Alexanian and Nair, while the ... More

Open Spin Chains in Super Yang-Mills at Higher Loops: Some Potential Problems with IntegrabilityMar 09 2006May 14 2006The super Yang-Mills duals of open strings attached to maximal giant gravitons are studied in perturbation theory. It is shown that non-BPS baryonic excitations of the gauge theory can be studied within the paradigm of open quantum spin chains even beyond ... More

Work distribution functions in polymer stretching experimentsSep 05 2004We compute the distribution of the work done in stretching a Gaussian polymer, made of N monomers, at a finite rate. For a one-dimensional polymer undergoing Rouse dynamics, the work distribution is a Gaussian and we explicitly compute the mean and width. ... More

Heat conduction in the disordered harmonic chain revisitedMay 04 2001A general formulation is developed to study heat conduction in disordered harmonic chains with arbitrary heat baths that satisfy the fluctuation-dissipation theorem. A simple formal expression for the heat current J is obtained, from which its asymptotic ... More

Noetherian Schemes over abelian symmetric monoidal categoriesOct 13 2014Jan 27 2016In this paper, we develop basic results of algebraic geometry over abelian symmetric monoidal categories. Let $A$ be a commutative monoid object in an abelian symmetric monoidal category $(\mathbf C,\otimes,1)$ satisfying certain conditions and let $\mathcal ... More

Dennis trace map for certain $K$-groups of categories with cofibrationsDec 18 2014Let $\mathcal C$ be a small category with cofibrations. In this paper, we define the $K$-theory and Hochschild homology groups of $\mathcal C$ of order $Y$, where $Y$ is an ordered finite simplicial set with basepoint. Further, we construct the Dennis ... More

L-functions for holomorphic forms on GSp(4) x GL(2) and their special valuesJul 03 2008Oct 29 2008We provide an explicit integral representation for L-functions of pairs (F,g) where F is a holomorphic genus 2 Siegel newform and g a holomorphic elliptic newform, both of squarefree levels and of equal weights. When F,g have level one, this was earlier ... More

A relation between multiplicity one and Bocherer's conjectureAug 14 2012Apr 10 2013We show that a weak form of the generalized Bocherer's conjecture implies multiplicity one for Siegel cusp forms of degree 2.

Determination of modular forms by fundamental Fourier coefficientsJul 30 2012Dec 17 2012This article is a research exposition based on the author's talk at the International Colloquium on Automorphic Representations and L-Functions, 2012, held at TIFR, Mumbai. We consider some special cases of the following question: when is a natural subset ... More

Conformal blocks on a 2-sphere with indistinguishable punctures and implications on black hole entropySep 04 2016The dimensionality of the Hilbert space of a Chern-Simons theory on a 3-fold, in the presence of Wilson lines carrying spin representations, had been counted by using its link with the Wess-Zumino theory, with level $k$, on the 2-sphere with points (to ... More

Thermodynamic partition function from quantum theory for black hole horizons in loop quantum gravityNov 30 2013Sep 22 2016We establish the link between the thermodynamics and the quantum theory of black hole horizons through the construction of the thermodynamic partition function, partly based on some physically plausible arguments, by beginning from the description of ... More

Energy spectrum of black holes : a new viewMar 20 2013Nov 08 2016Energy of a black hole is usually quantized by invoking some area quantization scheme after expressing the energy in terms of the horizon area. However, in this approach one has to quantize the local and asymptotic energy of the black hole separately ... More

Min Morse: Approximability & ApplicationsMar 11 2015Apr 08 2015We resolve an open problem posed by Joswig et al. by providing an $\tilde{O}(N)$ time, $O(\log^2(N))$-factor approximation algorithm for the min-Morse unmatched problem (MMUP) Let $\Lambda$ be the no. of critical cells of the optimal discrete Morse function ... More

A Supersymmetry Preserving Mass-Deformation of N=1 Super Yang-Mills in D=2+1Sep 04 2009Sep 18 2009We construct a massive non-abelian N= 1 SYM theory on R^3. This is achieved by using a non-local gauge and Poincare invariant mass term for gluons due to Nair. The underlying supersymmetry algebra is shown to be a non-central extension of the Poincare ... More

Comment on ``Can Disorder Induce a Finite Thermal Conductivity in 1D Lattices?''Jun 18 2001In a recent paper [Phys. Rev. Lett. 86, 63 (2001)], Li et al have reported that the nonequilibrium heat conducting steady state of a disordered harmonic chain is not unique. In this comment we point out that for a large class of stochastic heat baths ... More

Pure resolutions of unbounded complexes of modulesAug 24 2016Let $R$ be a commutative ring. We show that pure injective resolutions and pure projective resolutions can be constructed for unbounded complexes of $R$-modules. We use these to obtain a closed symmetric monoidal structure on the unbounded pure derived ... More

Motif Analysis in the Amazon Product Co-Purchasing NetworkDec 18 2010Online stores like Amazon and Ebay are growing by the day. Fewer people go to departmental stores as opposed to the convenience of purchasing from stores online. These stores may employ a number of techniques to advertise and recommend the appropriate ... More

Hybrid sup-norm bounds for Maass newforms of powerful levelSep 24 2015Oct 13 2015Let f be an L^2-normalized Hecke--Maass cuspidal newform of level N, character \chi and Laplace eigenvalue \lambda. Let N_1 denote the smallest integer such that N|N_1^2 and N_0 denote the largest integer such that N_0^2 |N. Let M denote the conductor ... More

The Microcanonical Entropy of Quantum Isolated Horizon, `quantum hair' $N$ and the Barbero-Immirzi parameter fixationMay 15 2012Mar 11 2014{\it If} the total number of punctures($N$) of a quantum isolated horizon is considered to be a macroscopic parameter alongside the Chern-Simons level($k$) or equivalently classical area$(A_{cl})$ a strict analysis of the {\it microcanonical} ensemble ... More

Field dynamics on the trapping horizon in Vaidya spacetimeJul 20 2016In this article, we shed some light on the field theoretic aspect of a generic {\it trapping horizon}(TH) with a view to probe beyond the Chern-Simons interpretation of an equilibrium TH, namely {\it isolated horizon}(IH) in the gauge theoretic formulation ... More

Novel fluctuations at constrained interfacesJan 25 2006In this study we try to answer the qustion : What happens when explicit constraints are introduced such that the low energy, long wavelength modes of a system are unavailable ? This question has assumed some importance in recent years due to the advent ... More

Supervised Classification of RADARSAT-2 Polarimetric Data for Different Land FeaturesAug 01 2016The pixel percentage belonging to the user defined area that are assigned to cluster in a confusion matrix for RADARSAT-2 over Vancouver area has been analysed for classification. In this study, supervised Wishart and Support Vector Machine (SVM) classifiers ... More

Heat Transport in low-dimensional systemsAug 24 2008Nov 19 2008Recent results on theoretical studies of heat conduction in low-dimensional systems are presented. These studies are on simple, yet nontrivial, models. Most of these are classical systems, but some quantum-mechanical work is also reported. Much of the ... More

Face Shape and Reflectance Acquisition using a Multispectral Light StageMay 18 2011In this thesis, we discuss the design and calibration (geometric and radiometric) of a novel shape and reflectance acquisition device called the "Multispectral Light Stage". This device can capture highly detailed facial geometry (down to the level of ... More

Sur la catégorie dérivée des faisceaux tordusOct 27 2014Soit $X$ un sch\'ema quasi-compact et s\'epar\'e et soit $\alpha\in \check{C}^2(X, \mathcal O_X^*)$ un cocycle de C\v{e}ch. Nous consid\'erons la cat\'egorie d\'eriv\'ee $D(QCoh(X,\alpha))$ des faisceaux quasi-coh\'erents sur $X$ tordu par $\alpha$. Soit ... More

Chow groups of ind-schemes and extensions of Saito's filtrationNov 07 2013Jun 16 2015Let $K$ be a field of characteristic zero and let $Sm/K$ be the category of smooth and separated schemes over $K$. For an ind-scheme $\mathcal X$ (and more generally for any presheaf of sets on $Sm/K$), we define its Chow groups $\{CH^p(\mathcal X)\}_{p\in ... More

Nonparametric Bayes Classification via Learning of Affine SubspacesJan 04 2013The goal of this presentation is to build an efficient non-parametric Bayes classifier in the presence of large numbers of predictors. When analyzing such data, parametric models are often too inflexible while non-parametric procedures tend to be non-robust ... More

Large values of newforms on GL(2) with highly ramified central characterDec 17 2014Sep 23 2015We give a lower bound for the sup-norm of an $L^2$-normalized newform in an irreducible, unitary, cuspidal representation $\pi$ of $GL_2$ over a number field. When the central character of $\pi$ is sufficiently ramified, this bound improves upon the trivial ... More

Existence and Multiplicity of a Nonhomogeneous Polyharmonic Equation With Critical Exponential Growth in Even DimensionApr 13 2015In this paper we study the existence of at least two positive weak solutions for an inhomogeneous fourth order equation with Navier boundary data involving nonlinearities of critical growth with a bifurcation parameter $\lambda$ in $\mathbb{R}^{2m}$. ... More

Aspects of Integrability in N =4 SYMAug 21 2007Various recently developed connections between supersymmetric Yang-Mills theories in four dimensions and two dimensional integrable systems serve as crucial ingredients in improving our understanding of the AdS/CFT correspondence. In this review, we highlight ... More

Mass-Gaps and Spin Chains for (Super) MembranesOct 01 2006We present a method for computing the non-perturbative mass-gap in the theory of Bosonic membranes in flat background spacetimes with or without background fluxes. The computation of mass-gaps is carried out using a matrix regularization of the membrane ... More

Heat conduction in a one-dimensional gas of elastically colliding particles of unequal massesFeb 12 2001We study the nonequlibrium state of heat conduction in a one-dimensional system of hard point particles of unequal masses interacting through elastic collisions. A BBGKY-type formulation is presented and some exact results are obtained from it. Extensive ... More

Ergodicity properties of energy conserving single spin flip dynamics in the XY modelApr 30 1998A single spin flip stochastic energy conserving dynamics for the XY model is considered. We study the ergodicity properties of the dynamics. It is shown that phase space trajectories densely fill the geometrically connected parts of the energy surface. ... More

Ancilla Assisted Quantum Information Processing: General protocols and NMR implementationsJan 02 2016While a bit is the fundamental unit of binary classical information, a qubit is the fundamental unit of quantum information. In quantum information processing (QIP), it is customary to call the qubits under study as system qubits, and the additional qubits ... More

Predicting Performance of a Face Recognition System Based on Image QualityOct 24 2015In this dissertation, we present a generative model to capture the relation between facial image quality features (like pose, illumination direction, etc) and face recognition performance. Such a model can be used to predict the performance of a face ... More

On integral schemes over symmetric monoidal categoriesJun 16 2015May 15 2016We propose notions of "Noetherian" and "integral" for schemes over an abelian symmetric monoidal category $(\mathcal C,\otimes,1)$. For Noetherian integral schemes, we construct a "function field" that is a commutative monoid object of $(\mathcal C,\otimes,1)$. ... More

On sup-norms of cusp forms of powerful levelApr 11 2014Nov 11 2015Let f be an L^2-normalized Hecke--Maass cuspidal newform of level N and Laplace eigenvalue \lambda. It is shown that |f|_\infty <<_{\lambda, \epsilon} N^{-1/12 + \epsilon} for any \epsilon>0. The exponent is further improved in the case when N is not ... More

On ratios of Petersson norms for Yoshida liftsMar 21 2013Apr 14 2013We prove an algebraicity property for a certain ratio of Petersson norms associated to a Siegel cusp form of degree 2 (and arbitrary level) whose adelization generates a weak endoscopic lift. As a preparation for this, we explicate various features of ... More

Siegel cusp forms of degree 2 are determined by their fundamental Fourier coefficientsJun 25 2011Jan 21 2012We prove that a Siegel cusp form of degree 2 for the full modular group is determined by its set of Fourier coefficients a(S) with 4 det(S) ranging over odd squarefree integers. As a key step to our result, we also prove that a classical cusp form of ... More

Prime density results for Hecke eigenvalues of a Siegel cusp formJul 27 2010Jul 30 2010Let F in S_k(Sp(2g, Z)) be a cuspidal Siegel eigenform of genus g with normalized Hecke eigenvalues mu_F(n). Suppose that the associated automorphic representation pi_F is locally tempered everywhere. For each c>0 we consider the set of primes p for which ... More

Modeling and Analysis of Walking Pattern for a Biped RobotAug 12 2015This paper addresses the design and development of an autonomous biped robot using master and worker combination of controllers. In addition, the bot is wirelessly controllable. The work presented here explains the walking pattern, system control and ... More

Higher Charges in Dynamical Spin Chains for SYM TheoryAug 19 2005Aug 30 2005We construct, to the first two non-trivial orders, the next conserved charge in the su(2|3) sector of N=4 Super Yang-Mills theory. This represents a test of integrability in a sector where the interactions change the number of sites of the chain. The ... More

A Key Distribution Scheme for Sensor Networks Using Structured GraphsJan 12 2010This paper presents a new key predistribution scheme for sensor networks based on structured graphs. Structured graphs are advantageous in that they can be optimized to minimize the parameter of interest. The proposed approach achieves a balance between ... More

Generating Function Formula of Heat Transfer in Harmonic NetworksDec 03 2010Jun 15 2011We consider heat transfer across an arbitrary harmonic network connected to two heat baths at different temperatures. The network has $N$ positional degrees of freedom, of which $N_L$ are connected to a bath at temperature $T_L$ and $N_R$ are connected ... More

Fluctuation theorem in quantum heat conductionMar 29 2007Jan 04 2008We consider steady state heat conduction across a quantum harmonic chain connected to reservoirs modelled by infinite collection of oscillators. The heat, $Q$, flowing across the oscillator in a time interval $\tau$ is a stochastic variable and we study ... More

Exact result for nonreciprocity in one-dimensional wave transmissionJul 22 2003For sound waves impinging on a one-dimensional medium, we show that nonlinearity can lead to nonreciprocal transmission, without dissipation or broken time reversal invariance. Placing quasi-monochromatic filters at the ends of the nonlinear medium, nonreciprocity ... More

Fault Tolerant Wireless Sensor MAC Protocol for Efficient Collision AvoidanceJun 17 2010In sensor networks communication by broadcast methods involves many hazards, especially collision. Several MAC layer protocols have been proposed to resolve the problem of collision namely ARBP, where the best achieved success rate is 90%. We hereby propose ... More

ContentFlow: Mapping Content to Flows in Software Defined NetworksFeb 06 2013Feb 07 2013Information-Centric Networks place content as the narrow waist of the network architecture. This allows to route based upon the content name, and not based upon the locations of the content consumer and producer. However, current Internet architecture ... More

Content as a Network PrimitiveDec 13 2012The current functionality supported by OpenFlowbased software defined networking (SDN) includes switching, routing, tunneling, and some basic fire walling while operating on traffic flows. However, the semantics of SDN do not allow for other operations ... More

Distribution of sizes of erased loops for loop-erased random walksApr 03 1997We study the distribution of sizes of erased loops for loop-erased random walks on regular and fractal lattices. We show that for arbitrary graphs the probability $P(l)$ of generating a loop of perimeter $l$ is expressible in terms of the probability ... More

On entropy in eulerian thermodynamicsJun 12 2011To the student of thermodynamics the most difficult subject is entropy. In this paper we examine the actual, practical application of entropy to two simple systems, the homogeneous slab with fixed boundary values of the temperature, and an isolated atmosphere ... More

VHDL Modeling of Intrusion Detection & Prevention System (IDPS) A Neural Network ApproachFeb 21 2014The rapid development and expansion of World Wide Web and network systems have changed the computing world in the last decade and also equipped the intruders and hackers with new facilities for their destructive purposes. The cost of temporary or permanent ... More

An Estimation Method of Measuring Image Quality for Compressed Images of Human FaceFeb 06 2014Nowadays digital image compression and decompression techniques are very much important. So our aim is to calculate the quality of face and other regions of the compressed image with respect to the original image. Image segmentation is typically used ... More

Resampling in Time Series ModelsJan 05 2012This project revolves around studying estimators for parameters in different Time Series models and studying their assymptotic properties. We introduce various bootstrap techniques for the estimators obtained. Our special emphasis is on Weighted Bootstrap. ... More

Primordial Magnetic Field Via Weibel Instability In The Quark Gluon Plasma PhaseMar 09 2016Sep 09 2016The origin of the observed large scale magnetic fields in the Universe is a mystery. The seed of these magnetic fields has been attributed to physical process in the early universe. In this work we provide a mechanism for the generation of a primordial ... More

Dynamics of Vibrated GrainsOct 06 2004We study number density distribution and the behavior of time correlation functions in the density of grains for a quasi-two dimensional system of vibrated grains. We study the system at various packing fractions, from low to high. At low densities we ... More

A Dynamic Service Description for Mobile EnvironmentsAug 08 2016With the increasing processing capability of mobile platforms and advancements in Internet of Things, modern mobile devices have shown a favorable prospect for on-the-go service provisioning. However, there is much to be done to realize this. A detailed, ... More

Near-separable Non-negative Matrix Factorization with $\ell_1$- and Bregman Loss FunctionsDec 27 2013Recently, a family of tractable NMF algorithms have been proposed under the assumption that the data matrix satisfies a separability condition Donoho & Stodden (2003); Arora et al. (2012). Geometrically, this condition reformulates the NMF problem as ... More

Dithered quantizers with negligible in-band dither powerFeb 05 2012Subtractive dithered quantizers are examined to minimize the signal-band dither power. The design of finite impulse response(FIR) filters that shape most of the dither-power out of the signal band while maintaining the benefits of dithering are dealt ... More

Efficiency Loss in Revenue Optimal AuctionsMay 07 2010Sep 13 2010We study efficiency loss in Bayesian revenue optimal auctions. We quantify this as the worst case ratio of loss in the realized social welfare to the social welfare that can be realized by an efficient auction. Our focus is on auctions with single-parameter ... More

Optimal Control for Generalized Network-Flow ProblemsNov 26 2016We consider the problem of throughput-optimal packet dissemination, in the presence of an arbitrary mix of unicast, broadcast, multicast and anycast traffic, in a general wireless network. We propose an online dynamic policy, called Universal Max-Weight ... More

Hypercomputation, Frege, Deleuze: Solving Thomson's LampMar 19 2015We present the first known solution to the original supertask, the Thomson Lamp Paradox. We also offer preliminary resources for classifying computational complexity of various supertasks. In so doing we consider a newly apparent paradox between the metrical ... More

On the order of vanishing of newforms at cuspsSep 28 2016We obtain an explicit formula, as a product of local terms, for the ramification index at each cusp for a modular parametrization of an elliptic curve over $\mathbb{Q}$. Our formula shows that the ramification index always divides 24, a fact that had ... More

Internet voting protocol based on implicit data securityJan 11 2010This paper presents a new protocol for Internet voting based on implicit data security. This protocol allows recasting of votes, which permits a change of mind by voters either during the time window over which polling is open or during a shorter period ... More

Space Efficient Secret SharingJan 29 2009Feb 18 2009This note proposes a method of space efficient secret sharing in which k secrets are mapped into n shares (n>=k) of the same size. Since, n can be chosen to be equal to k, the method is space efficient. This method may be compared with conventional secret ... More

Manifest SO(N) invariance and S-matrices of three-dimensional N=2,4,8 SYMMar 03 2011An on-shell formalism for the computation of S-matrices of SYM theories in three spacetime dimensions is presented. The framework is a generalization of the spinor-helicity formalism in four dimensions. The formalism is applied to establish the manifest ... More

Deconstructing Supersymmetric S-matrices in D <= 2 + 1Jun 08 2012Global supersymmetries of the S-matrices of N = 2, 4, 8 supersymmetric Yang-Mills theories in three spacetime dimensions (without matter hypermultiplets) are shown to be SU(1|1), SU(2|2) and SU(2|2) X SU(2|2) respectively. These symmetries are not manifest ... More

Hidden Local and Non-local Symmetries of S-matrices of N=2,4,8 SYM in D=2+1Sep 13 2011Sep 26 2011This talk, based principally on arXiv:1103.0786, is devoted to properties of tree-level S-matrices of N=2,4,8 SYM in D=2+1. We'll discuss an on-shell formalism for three-dimensional theories inspired by the spinor-helicity framework in four spacetime ... More

Using higher-order Fourier analysis over general fieldsMay 04 2015Higher-order Fourier analysis, developed over prime fields, has been recently used in different areas of computer science, including list decoding, algorithmic decomposition and testing. We extend the tools of higher-order Fourier analysis to analyze ... More

List decoding Reed-Muller codes over small fieldsJul 13 2014Jul 17 2014The list decoding problem for a code asks for the maximal radius up to which any ball of that radius contains only a constant number of codewords. The list decoding radius is not well understood even for well studied codes, like Reed-Solomon or Reed-Muller ... More

Forced desorption of semiflexible polymers, adsorbed and driven by molecular motorsNov 11 2014Oct 18 2015We formulate and characterize a model to describe the dynamics of semiflexible polymers in the presence of activity due to motor proteins attached irreversibly to a substrate, and a transverse pulling force acting on one end of the filament. The stochastic ... More

3D Scene Grammar for Parsing RGB-D PointcloudsNov 08 2012We pose 3D scene-understanding as a problem of parsing in a grammar. A grammar helps us capture the compositional structure of real-word objects, e.g., a chair is composed of a seat, a back-rest and some legs. Having multiple rules for an object helps ... More

Non-equilibrium Green's function formalism and the problem of bound statesOct 12 2005Mar 02 2006The non-equilibrium Green's function formalism for infinitely extended reservoirs coupled to a finite system can be derived by solving the equations of motion for a tight-binding Hamiltonian. While this approach gives the correct density for the continuum ... More

Heat conduction in the disordered Fermi-Pasta-Ulam chainJun 25 2008We address the question of the effect of disorder on heat conduction in an anharmonic chain with interactions given by the Fermi-Pasta-Ulam (FPU) potential. In contrast to the conclusions of an earlier paper [Phys. Rev. Lett. 86, 63 (2001)] which found ... More

Triple minima in free energy of semiflexible polymersMar 23 2002Jul 19 2002We study the free energy of the worm-like-chain model, in the constant-extension ensemble, as a function of the stiffness for finite chains of length L. We find that the polymer properties obtained in this ensemble are "qualitatively" different from those ... More

Non-local symmetries for Yang-Mills theories and their massive counterparts in two and three dimensionsDec 05 2011We identify a non-local symmetry for Yang-Mills theories in 1+1 and 2+1 spacetime dimensions. The symmetry mixes a vector current with the gauge field. The current involved in the symmetry is required to satisfy certain constraints. The explicit solution ... More

Fullerenes, Zero-modes, and Self-adjoint ExtensionsSep 08 2009We consider the low-energy electronic properties of graphene cones in the presence of a global Fries-Kekul\'e Peierls distortion. Such cones occur in fullerenes as the geometric response to the disclination associated with pentagon rings. It is well known ... More

Exploring MSSM for Charge and Color Breaking and Other Constraints in the Context of Higgs@125 GeVSep 02 2014Sep 26 2014Exploring MSSM parameter space after the discovery of Higgs Boson with mass 125 GeV naturally demands large top-squark mixing or large trilinear coupling parameter $A_t$ in particular, so as to avoid excessively heavy squark, specially for the universal ... More

A Parallel Encryption Algorithm for Block Ciphers Based on Reversible Programmable Cellular AutomataJun 14 2010A Cellular Automata (CA) is a computing model of complex System using simple rule. In CA the problem space into number of cell and each cell can be one or several final state. Cells are affected by neighbours' to the simple rule. Cellular Automata are ... More

Mitigating Timing Errors in Time-Interleaved ADCs: a signal conditioning approachApr 04 2012Novel techniques based on signal-conditioning are presented to mitigate timing errors in time-interleaved ADCs. A theoretical bound on the achievable spurious signal content, on applying the techniques, is also derived. Behavioral simulations corroborating ... More

Equilibrium dynamical correlations in the Toda chain and other integrable modelsAug 18 2016We investigate the form of equilibrium spatio-temporal correlation functions of conserved quantities, and of energy transport in the Toda lattice and in other integrable models. From numerical simulations we find that the correlations satisfy ballistic ... More

Non-equilibrium work fluctuations for oscillators in non-Markovian bathsDec 01 2006We study work fluctuation theorems for oscillators in non-Markovian heat baths. By calculating the work distribution function for a harmonic oscillator with motion described by the generalized Langevin equation, the Jarzynski equality (JE), transient ... More