Results for "Piyush Rai"

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Stochastic Blockmodels meet Graph Neural NetworksMay 14 2019Stochastic blockmodels (SBM) and their variants, $e.g.$, mixed-membership and overlapping stochastic blockmodels, are latent variable based generative models for graphs. They have proven to be successful for various tasks, such as discovering the community ... More
The Infinite Hierarchical Factor Regression ModelAug 05 2009We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with ... More
A Simple Exponential Family Framework for Zero-Shot LearningJul 25 2017Jan 25 2018We present a simple generative framework for learning to predict previously unseen classes, based on estimating class-attribute-gated class-conditional distributions. We model each class-conditional distribution as an exponential family distribution and ... More
Zero-Truncated Poisson Tensor Factorization for Massive Binary TensorsAug 18 2015We present a scalable Bayesian model for low-rank factorization of massive tensors with binary observations. The proposed model has the following key properties: (1) in contrast to the models based on the logistic or probit likelihood, using a zero-truncated ... More
Streamed Learning: One-Pass SVMsAug 05 2009We present a streaming model for large-scale classification (in the context of $\ell_2$-SVM) by leveraging connections between learning and computational geometry. The streaming model imposes the constraint that only a single pass over the data is allowed. ... More
Neutrino Masses, Baryon Asymmetry, Dark Matter and the Moduli Problem : A Complete FrameworkSep 15 2008Sep 16 2009Recent developments in string theory have led to "realistic" string compactifications which lead to moduli stabilization while generating a hierarchy between the Electroweak and Planck scales at the same time. However, this seems to suggest a rethink ... More
Connecting String/M Theory to the Electroweak Scale and to LHC DataJun 11 2007Sep 13 2007The Standard Model of particle physics explains (almost) all observed non-gravitational microscopic phenomena but has many open theoretical questions. We are on the threshold of unraveling the mysteries of the Standard Model and discovering its extension. ... More
Development of Tool for Mapping Conventional Circuit to Reversible LogicJul 02 2014In the last decades, great achievements have been made in the development of computing machines. However, due to exponential growth of transistor density and in particular due to tremendously increasing power consumption, researchers expect that "Conventional ... More
The Leptonic Higgs and Dark MatterOct 05 2009This is a short review of the framework proposed in \cite{Goh:2009wg} which gives rise to indirect Dark Matter (DM) signals explaining the recent cosmic-ray anomalies and links cosmic-ray signals of DM to LHC signals of a leptonic Higgs sector.The states ... More
Modeling and Control of CSTR using Model based Neural Network Predictive ControlAug 17 2012This paper presents a predictive control strategy based on neural network model of the plant is applied to Continuous Stirred Tank Reactor (CSTR). This system is a highly nonlinear process; therefore, a nonlinear predictive method, e.g., neural network ... More
Generalized Zero-Shot Learning via Synthesized ExamplesDec 11 2017Jun 12 2018We present a generative framework for generalized zero-shot learning where the training and test classes are not necessarily disjoint. Built upon a variational autoencoder based architecture, consisting of a probabilistic encoder and a probabilistic conditional ... More
Play and Prune: Adaptive Filter Pruning for Deep Model CompressionMay 11 2019While convolutional neural networks (CNN) have achieved impressive performance on various classification/recognition tasks, they typically consist of a massive number of parameters. This results in significant memory requirement as well as computational ... More
Group-theoretical Structure of the Entangled States of N Identical ParticlesJun 23 2000We provide a group-theoretical classification of the entangled states of N identical particles. The connection between quantum entanglement and the exchange symmetry of the states of N identical particles is made explicit using the duality between the ... More
Entangled States of N Identical ParticlesMar 15 2000We explore the connection between quantum entanglement and the exchange symmetry of the states of N identical particles. Each particle has n-levels. The N particles span the nN dimensional Hilbert space. We shall call the general state of the particle ... More
Leveraging Filter Correlations for Deep Model CompressionNov 26 2018We present a filter correlation based model compression approach for deep convolutional neural networks. Our approach iteratively identifies pairs of filters with largest pairwise correlations and discards one of the filters from each such pair. However, ... More
Generative Model for Zero-Shot Sketch-Based Image RetrievalApr 18 2019We present a probabilistic model for Sketch-Based Image Retrieval (SBIR) where, at retrieval time, we are given sketches from novel classes, that were not present at training time. Existing SBIR methods, most of which rely on learning class-wise correspondences ... More
Comparison of Entropies in the Light of SeparabilitySep 28 2002Oct 08 2002This paper has been withdrawn by the author(s) in the light of several other works available and due to a misunderstanding in the authorships.
Earliness-Aware Deep Convolutional Networks for Early Time Series ClassificationNov 14 2016We present Earliness-Aware Deep Convolutional Networks (EA-ConvNets), an end-to-end deep learning framework, for early classification of time series data. Unlike most existing methods for early classification of time series data, that are designed to ... More
HetConv: Heterogeneous Kernel-Based Convolutions for Deep CNNsMar 11 2019We present a novel deep learning architecture in which the convolution operation leverages heterogeneous kernels. The proposed HetConv (Heterogeneous Kernel-Based Convolution) reduces the computation (FLOPs) and the number of parameters as compared to ... More
Deep Generative Models for Sparse, High-dimensional, and Overdispersed Discrete DataMay 02 2019Many applications, such as text modelling, high-throughput sequencing, and recommender systems, require analysing sparse, high-dimensional, and overdispersed discrete (count/binary) data. With the ability of handling high-dimensional and sparse discrete ... More
Flexible Modeling of Latent Task Structures in Multitask LearningJun 27 2012Multitask learning algorithms are typically designed assuming some fixed, a priori known latent structure shared by all the tasks. However, it is usually unclear what type of latent task structure is the most appropriate for a given multitask learning ... More
Scalable Bayesian Non-Negative Tensor Factorization for Massive Count DataAug 18 2015We present a Bayesian non-negative tensor factorization model for count-valued tensor data, and develop scalable inference algorithms (both batch and online) for dealing with massive tensors. Our generative model can handle overdispersed counts as well ... More
HetConv: Heterogeneous Kernel-Based Convolutions for Deep CNNsMar 11 2019Mar 25 2019We present a novel deep learning architecture in which the convolution operation leverages heterogeneous kernels. The proposed HetConv (Heterogeneous Kernel-Based Convolution) reduces the computation (FLOPs) and the number of parameters as compared to ... More
Small-Variance Asymptotics for Nonparametric Bayesian Overlapping Stochastic BlockmodelsJul 10 2018The latent feature relational model (LFRM) is a generative model for graph-structured data to learn a binary vector representation for each node in the graph. The binary vector denotes the node's membership in one or more communities. At its core, the ... More
Optimal transport over nonlinear systems via infinitesimal generators on graphsDec 04 2016Apr 10 2018We present a set-oriented graph-based computational framework for continuous-time optimal transport over nonlinear dynamical systems. We recover provably optimal control laws for steering a given initial distribution in phase space to a final distribution ... More
Electroweak Baryogenesis and Dark Matter with an approximate R-symmetryJul 08 2011It is well known that R-symmetric models dramatically alleviate the SUSY flavor and CP problems. We study particular modifications of existing R-symmetric models which share the solution to the above problems, and have interesting consequences for electroweak ... More
Learning formation energy of inorganic compounds using matrix variate deep Gaussian processDec 22 2018Future advancement of engineering applications is dependent on design of novel materials with desired properties. Enormous size of known chemical space necessitates use of automated high throughput screening to search the desired material. The high throughput ... More
Bounds on Minimum Number of Anchors for Iterative Localization and its Connections to Bootstrap PercolationMay 22 2012Iterated localization is considered where each node of a network needs to get localized (find its location on 2-D plane), when initially only a subset of nodes have their location information. The iterated localization process proceeds as follows. Starting ... More
Dynamics on AdS2 and Enlargement of SL(2,R) to c=1 `cut-off Virasoro Algebra'Apr 17 2001We consider the enhancement of SL(2,R) to Virasoro algebra in a system of N particles on AdS2. We restrict our discussion to the case of non-interacting particles, and argue that they must be treated as fermions. We find operators L_n whose commutators ... More
Quantum de-mixing in binary mixtures of dipolar bosonsApr 26 2010Aug 31 2010Quantum Monte Carlo simulations of a two-component Bose mixture of trapped dipolar atoms of identical masses and dipole moments, provide numerical evidence of de-mixing at low finite temperatures. De-mixing occurs as a consequence of quantum statistics, ... More
A simplified proof of a Lee-Yang type theoremJul 22 2014In this short note, we give a simple proof of a Lee-Yang type theorem which appeared in "Lee-Yang theorems and the complexity of computing averages" by Alistair Sinclair and Piyush Srivastava.
Optimal perturbations for nonlinear systems using graph-based optimal transportNov 18 2016Oct 06 2017We formulate and solve a class of finite-time transport and mixing problems in the set-oriented framework. The aim is to obtain optimal discrete-time perturbations in nonlinear dynamical systems to transport a specified initial measure on the phase space ... More
Correlated Link Shadow Fading in Multi-hop Wireless NetworksApr 17 2008Apr 18 2008Accurate representation of the physical layer is required for analysis and simulation of multi-hop networking in sensor, ad hoc, and mesh networks. This paper investigates, models, and analyzes the correlations that exist in shadow fading between links ... More
Learning formation energy of inorganic compounds using matrix variate deep Gaussian processDec 22 2018Apr 09 2019Future advancement of engineering applications is dependent on design of novel materials with desired properties. Enormous size of known chemical space necessitates use of automated high throughput screening to search the desired material. The high throughput ... More
Redimensioning of Euclidean SpacesJul 26 2013A vector space over a field $\mathbb{F}$ is a set $V$ together with two binary operations, called vector addition and scalar multiplication. It is standard practice to think of a Euclidean space $\mathbb{R}^n$ as an $n$-dimensional real coordinate space ... More
Open source software and peer reviewAug 23 2003Sep 07 2003We compare the open source model of software development to peer review in academia.
Student Dropout Risk Assessment in Undergraduate Course at Residential UniversityMay 15 2014Student dropout prediction is an indispensable for numerous intelligent systems to measure the education system and success rate of any university as well as throughout the university in the world. Therefore, it becomes essential to develop efficient ... More
The spectrum of a random geometric graph is concentratedAug 09 2004Sep 23 2004Consider $n$ points distributed uniformly in $[0,1]^d$. Form a graph by connecting two points if their mutual distance is no greater than $r(n)$. This gives a random geometric graph, $\gnrn$, which is connected for appropriate $r(n)$. We show that the ... More
A Generalized Polynomial Chaos-Based Method for Efficient Bayesian Calibration of Uncertain Computational ModelsNov 01 2012This paper addresses the Bayesian calibration of dynamic models with parametric and structural uncertainties, in particular where the uncertain parameters are unknown/poorly known spatio-temporally varying subsystem models. Independent stationary Gaussian ... More
A Generative Approach to Zero-Shot and Few-Shot Action RecognitionJan 27 2018We present a generative framework for zero-shot action recognition where some of the possible action classes do not occur in the training data. Our approach is based on modeling each action class using a probability distribution whose parameters are functions ... More
Quantum Cyclic Code of length dividing $p^{t}+1$Nov 26 2010Mar 25 2011In this paper, we study cyclic stabiliser codes over $\mathbb{F}_p$ of length dividing $p^t+1$ for some positive integer $t$. We call these $t$-Frobenius codes or just Frobenius codes for short. We give methods to construct them and show that they have ... More
A Dynamic Bi-orthogonal Field Equation Approach for Efficient Bayesian Calibration of Large-Scale SystemsNov 01 2012Nov 13 2012This paper proposes a novel computationally efficient dynamic bi-orthogonality based approach for calibration of a computer simulator with high dimensional parametric and model structure uncertainty. The proposed method is based on a decomposition of ... More
Distributed Resource Allocation for Proportional Fairness in Multi-Band Wireless SystemsFeb 13 2011A challenging problem in multi-band multi-cell self-organized wireless systems, such as multi-channel Wi-Fi networks, femto/pico cells in 3G/4G cellular networks, and more recent wireless networks over TV white spaces, is of distributed resource allocation. ... More
Visible Sector Supersymmetry Breaking RevisitedJan 20 2004We revisit the possibility of "visible sector" SUSY models: models which are straightforward renormalizable extensions of the Minimal Supersymmetric Standard Model (MSSM), where SUSY is broken at tree level. Models of this type were abandoned twenty years ... More
Deep Recurrent Neural Networks for Time Series PredictionJul 22 2014Dec 18 2014Ability of deep networks to extract high level features and of recurrent networks to perform time-series inference have been studied. In view of universality of one hidden layer network at approximating functions under weak constraints, the benefit of ... More
Father time. II. A physical basis behind Feynman's idea of antiparticles moving backward in time, and an extension of the CPT theorem to include non-local gauge fieldsJun 17 1999Oct 21 1999It has been demonstrated in a recent paper (Mod.Phys.Lett. A13, 1265 (1998); hep-th/9902020) that the existence of a non-thermodynamic arrow of time at the atomic level is a fundamental requirement for conservation of energy in matter-radiation interaction. ... More
Quantum uncertainties in coupled harmonic oscillatorOct 05 1995Jan 20 1996In this paper we analyze the quantum uncertainties and the photon statistics in the interaction between the two modes of radiation by treating them as coupled harmonic oscillator with the motivation of controlling quantum properties of one light beam ... More
Geometrical Representation of Angular Momentum Coherence and SqueezingDec 17 2000A simple, and elegant geometrical representation is developed to describe the concept of coherence and squeezing for angular momentum operators. Angular momentum squeezed states were obtained by applying Bogoliubov transformation on the angular momentum ... More
On the order of the Schur multiplier of $p$-groupsMay 06 2017We give a bound on the order of the Schur multiplier of $p$-groups refining earlier bounds. As an application we complete the classification of groups having Schur multiplier of maximum order. Finally we prove that the order of the Schur multiplier of ... More
A Possible Anisotropy in Blackbody Radiation Viewed through Non-uniform Gaseous MatterMar 12 1999Jun 07 1999A non-local gauge symmetry of a complex scalar field, which can be trivially extended to spinor fields, was demonstrated in a recent paper (Mod.Phys.Lett. A13, 1265 (1998) ; hep-th/9902020). The corresponding covariant Lagrangian density yielded a new, ... More
Squeezing in the interaction of radiation with two-level atomsSep 25 1995Oct 05 1995We propose a simple experimental procedure to produce squeezing and other non-classical properties like photon antibunching of radiation, and amplification without population inversion. The method also decreases the uncertainties of the angular-momentum ... More
A Technique for Designing Stabilizing Distributed Controllers with Arbitrary Signal Structure ConstraintsSep 15 2012This paper presents a new approach to distributed controller design that exploits a partial-structure representation of linear time invariant systems to characterize the structure of a system. This partial-structure representation, called the dynamical ... More
Father Time. I. Does the Cosmic Microwave Background Radiation Provide a Universal Arrow of Time ?Mar 15 1999Oct 21 1999The existence of a non-thermodynamic arrow of time was demonstrated in a recent paper (Mod.Phys.Lett. A13, 1265 (1998)), in which a model of non-local Quantum Electrodynamics was formulated through the principle of gauge invariance. In this paper we show ... More
Associated Photons and New Physics Signals at Linear CollidersFeb 15 2008We study signals for beyond standard model physics and consider the virtues of single photon signals or associated photons in the final states in identifying different scenarios of new physics models in a very efficient and novel way.
Identifying new physics contributions in the Higgs sector at linear e+e- collidersAug 10 2006Loop driven decay modes of the Higgs are sensitive to new physics contributions because of new particles in the loops. To highlight this we look at the dilepton-dijet signal in the dominant Higgs production channel at a linear e+e- collider. We show that ... More
The golden age of Calcutta physics: Difficulties in reconstructing the historyDec 08 2016Classes started in the newly established Physics Department of Calcutta University Science College in 1916. Raman, Bose and Saha were three young members of the small physics faculty consisting of barely half a dozen faculty members. Within about one ... More
Starspots, Stellar Cycles and Stellar Flares: Lessons from Solar Dynamo ModelsDec 08 2016In this review, we discuss whether the present solar dynamo models can be extrapolated to explain various aspects of stellar activity. We begin with a summary of the following kinds of data for solar-like stars: (i) data pertaining to stellar cycles from ... More
Topology Discovery Using Path InterferenceMar 17 2019We consider the problem of inferring the topology of a network using the measurements available at the end nodes, without cooperation from the internal nodes. To this end, we provide a simple method to obtain path interference which identifies whether ... More
Strong Quantum Solutions in Conflicting Interest Bayesian GamesMay 12 2017Nov 16 2017Quantum entanglement has been recently demonstrated as a useful resource in conflicting interest games of incomplete information between two players, Alice and Bob [Pappa et al., Phys. Rev. Lett. 114, 020401 (2015)]. General setting for such games is ... More
A higher order numerical scheme for singularly perturbed parabolic turning point problems exhibiting twin boundary layersMay 08 2019In this article, a parameter-uniform numerical method is presented to solve one-dimensional singularly perturbed parabolic convection-diffusion turning point problem exhibiting two exponential boundary layers. We study the asymptotic behaviour of the ... More
A note on the order of the Schur multiplier of p-groupsJun 05 2016Let $G$ be a finite $p$-group of order $p^n$ with $|G'| = p^k$. Let $M(G)$ denotes the Schur multiplier of $G$. A classical result of Green states that $|M(G)| \leq p^{\frac{1}{2}n(n-1)}$. In 2009, Niroomand, improving Green's and other bounds on $|M(G)|$ ... More
Robust numerical schemes for singularly perturbed delay parabolic convection diffusion problems with degenerate coefficientMay 08 2019This article studies a dirichlet boundary value problem for singularly perturbed time delay convection diffusion equation with degenerate coefficient. A priori explicit bounds are established on the solution and its derivatives. For asymptotic analysis ... More
Effects of Universal Extra Dimensions on Higgs signals at LHCOct 26 2005Nov 21 2007A major focus at the Large Hadron Collider (LHC) will be Higgs boson studies and it would be an interesting prospect to simultaneously probe for physics beyond the Standard Model (SM) in the Higgs signals. In this work we show as to what extent, the effects ... More
Fermionic spectrum from a domain wall in five dimensionsApr 12 2019We study fermions in a domain wall backgrounds in five dimensional supergravity, which is similar to zero temperature limit of holographic superconductor. We find the fermionic operators for small charges in the dual four dimensional theory have gapped ... More
Tilted Bianchi Type V Bulk Viscous Cosmological Models in General RelativityJul 10 2003Conformally flat tilted Bianchi type V cosmological models in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. Some physical and geometric aspects of ... More
Tilted Bianchi Type I Cosmological Models Filled with Disordered Radiation in General Relativity RevisitedDec 26 2002Tilted Bianchi type I cosmological models filled with disordered radiation in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. Some physical and geometric ... More
Zero-Shot Learning via Class-Conditioned Deep Generative ModelsNov 15 2017Nov 19 2017We present a deep generative model for learning to predict classes not seen at training time. Unlike most existing methods for this problem, that represent each class as a point (via a semantic embedding), we represent each seen/unseen class using a class-specific ... More
On the dimension of the Schur multiplier of nilpotent Lie algberasMay 09 2017We give a bound on the dimension of the Schur multiplier of a finite dimensional nilpotent Lie algebra which sharpens the earlier known bounds.
An Approach to Provide Security in Mobile Ad-Hoc Networks Using Counter Mode of Encryption on Mac LayerOct 15 2011Security in any of the networks became an important issue in this paper we have implemented a security mechanism on Medium Access Control layer by Assured Neighbor based Security Protocol to provide authentication and confidentiality of packets along ... More
Compactified String Theories -- Generic Predictions for Particle PhysicsApr 12 2012In recent years it has been realized that in string/$M$ theories compactified to four dimensions which satisfy cosmological constraints, it is possible to make some generic predictions for particle physics and dark matter: a non-thermal cosmological history ... More
Enhanced velocity fluctuations in interacting swimmer suspensionsFeb 14 2019A dilute non-interacting suspension of micro-swimmers exhibits a finite velocity variance and short-ranged correlations that decay over a swimmer length. For a suspension of interacting straight swimmers, however, pair-interactions leads to a non-decaying ... More
On the observation of nonclassical excitations in Bose-Einstein condensatesJan 25 2016In the recent experimental and theoretical literature well-established nonclassicality criteria from the field of quantum optics have been directly applied to the case of excitations in matter-waves. Among these are violations of Cauchy-Schwarz inequalities, ... More
LHC String PhenomenologyOct 03 2006Jun 05 2007We argue that it is possible to address the deeper LHC Inverse Problem, to gain insight into the underlying theory from LHC signatures of new physics. We propose a technique which may allow us to distinguish among, and favor or disfavor, various classes ... More
Nonmonotonic crossover and scaling behaviors in a disordered 1D quasicrystalSep 17 2018Jan 17 2019We consider a noninteracting disordered 1D quasicrystal in the weak disorder regime. We show that the critical states of the pure model approach strong localization in strikingly different ways, depending on their renormalization properties. A finite ... More
Bayesian Optimal Design of Experiments For Inferring The Statistical Expectation Of A Black-Box FunctionJul 26 2018Jan 15 2019Bayesian optimal design of experiments (BODE) has been successful in acquiring information about a quantity of interest (QoI) which depends on a black-box function. BODE is characterized by sequentially querying the function at specific designs selected ... More
Extending Expected Improvement for High-dimensional Stochastic Optimization of Expensive Black-Box FunctionsApr 05 2016May 19 2016Design optimization under uncertainty is notoriously difficult when the objective function is expensive to evaluate. State-of-the-art techniques, e.g, stochastic optimization or sampling average approximation, fail to learn exploitable patterns from collected ... More
Towards a Queueing-Based Framework for In-Network Function ComputationMay 27 2011Jun 22 2012We seek to develop network algorithms for function computation in sensor networks. Specifically, we want dynamic joint aggregation, routing, and scheduling algorithms that have analytically provable performance benefits due to in-network computation as ... More
A mean-field game model for homogeneous flockingMar 14 2018May 29 2018Empirically derived continuum models of collective behavior among large populations of dynamic agents are a subject of intense study in several fields, including biology, engineering and finance. We formulate and study a mean-field game model whose behavior ... More
Role of Inter-site Hybrid Interactions in Itinerant FerromagnetismDec 12 2003We study role of inter-site hybrid interactions in deciding ferromagnetic state in the itinerant electron (narrow band) systems like some of the transition metals. We have considered Hubbard like tight binding model alongwith exchange and hybrid interactions. ... More
Common Representation Learning Using Step-based Correlation Multi-Modal CNNOct 31 2017Deep learning techniques have been successfully used in learning a common representation for multi-view data, wherein the different modalities are projected onto a common subspace. In a broader perspective, the techniques used to investigate common representation ... More
Quasinormal modes of scalar and Dirac perturbations of Bardeen de-Sitter black holesMar 13 2017Jul 20 2017So far the study of black hole perturbations has been mostly focussed upon the classical black holes with singularities at the origin and hidden by event horizon. Compared to that, the regular black holes are a completely new class of solutions arising ... More
Energy-Efficient Communication over the Unsynchronized Gaussian Diamond NetworkJan 08 2014Jul 08 2014Communication networks are often designed and analyzed assuming tight synchronization among nodes. However, in applications that require communication in the energy-efficient regime of low signal-to-noise ratios, establishing tight synchronization among ... More
The Balanced Unicast and Multicast Capacity Regions of Large Wireless NetworksSep 08 2008Jan 21 2010We consider the question of determining the scaling of the $n^2$-dimensional balanced unicast and the $n 2^n$-dimensional balanced multicast capacity regions of a wireless network with $n$ nodes placed uniformly at random in a square region of area $n$ ... More
On Capacity Scaling in Arbitrary Wireless NetworksNov 19 2007Aug 03 2009In recent work, Ozgur, Leveque, and Tse (2007) obtained a complete scaling characterization of throughput scaling for random extended wireless networks (i.e., $n$ nodes are placed uniformly at random in a square region of area $n$). They showed that for ... More
An M Theory Solution to the Strong CP Problem and Constraints on the AxiverseApr 28 2010Oct 31 2010We give an explicit realization of the "String Axiverse" discussed in Arvanitaki et. al \cite{Arvanitaki:2009fg} by extending our previous results on moduli stabilization in $M$ theory to include axions. We extend the analysis of \cite{Arvanitaki:2009fg} ... More
Structure, Bose-Einstein condensation and superfluidity of two-dimensional confined dipolar assembliesApr 04 2011Jun 27 2011Low temperature properties of harmonically confined two-dimensional assemblies of dipolar bosons are systematically investigated by Monte Carlo simulations. Calculations carried out for different numbers of particles and strengths of the confining potential ... More
S and T for SCFTsDec 12 2012We develop a general set of methods for computing the oblique electroweak parameters S and T for bottom-up and top-down motivated scenarios in which the Higgs weakly mixes with a superconformal extra sector. In addition to their utility in phenomenological ... More
Exact recovery in the Ising blockmodelDec 12 2016Feb 02 2017We consider the problem associated to recovering the block structure of an Ising model given independent observations on the binary hypercube. This new model, called the Ising blockmodel, is a perturbation of the mean field approximation of the Ising ... More
Hochschild cohomology of group extensions of quantum symmetric algebrasNov 19 2009May 24 2010Quantum symmetric algebras (or noncommutative polynomial rings) arise in many places in mathematics. In this article we find the multiplicative structure of their Hochschild cohomology when the coefficients are in an arbitrary bimodule algebra. When this ... More
Why do millisecond pulsars have weaker magnetic fields compared to ordinary pulsars?Nov 03 2003Millisecond pulsars, with magnetic fields weaker by three to four orders compared to those of ordinary pulsars, are presumed to be neutron stars spun up by binary accretion. We expect the magnetic field to get screened by the accreted material. Our simulation ... More
Diamagnetic Screening of the Magnetic Field in Accreting Neutron StarsFeb 13 2002Dec 12 2002A possible mechanism for screening of the surface magnetic field of an accreting neutron star, by the accreted material, is investigated. In particular, we investigate the nature of the evolution of the internal field configuration in the case of a) a ... More
Nonextensive thermodynamic formalism for chaotic dynamical systemsSep 15 1999A nonextensive thermostatic approach to chaotic dynamical systems is developed by expressing generalized Tsallis distribution as escort distribution. We explicitly show the thermodynamic limit and also derive the Legendre Transform structure. As an application, ... More
Density fluctuation in extended inflationDec 20 1996We examine the calculation of density perturbation at large scales in the inflationary scenario. The formula for its magnitude is reviewed from first principles and applied to the original model of extended inflation. Our estimate is an order of magnitude ... More
Diamagnetic Screening of the Magnetic Field in Accreting Neutron StarsAug 14 2001Jan 27 2002A possible mechanism for screening of the surface magnetic field of an accreting neutron star, by the accreted material, is investigated. We model the material flow in the surface layers of the star by an assumed 2-D velocity field satisfying all the ... More
The treatment of magnetic buoyancy in flux transport dynamo modelsNov 12 2015One important ingredient of flux transport dynamo models is the rise of the toroidal magnetic field through the convection zone due to magnetic buoyancy to produce bipolar sunspots and then the generation of the poloidal magnetic field from these bipolar ... More
The scattering and extinction properties of nanodiamondsNov 02 2009The study of scattering and extinction properties of possible nanodiamond grains in the ISM are reported. Calculations using Discrete Dipole Approximation (DDA) for varying ellipsoidal shapes and sizes from 2.5 to $10 nm$ are considered. Nanodiamonds ... More
Associated single photons and doubly charged scalar at linear e-e- collidersAug 10 2006Oct 12 2006Doubly charged scalars, predicted in many models having exotic Higgs representations, can in general have lepton-number violating (LFV) couplings. We show that by using an associated monoenergetic final state photon seen at a future linear e-e- collider, ... More
Associated single photons as signals for a doubly charged scalar at linear e-e- collidersAug 29 2005Dec 04 2005Doubly charged scalars, predicted in many models having exotic Higgs representations, can in general have lepton-number violating (LFV) couplings. The basis of most searches for this charged scalar has been to look for its direct production and its subsequent ... More
Negativity and Concurrence as complete entanglement measures for two arbitrary quditsAug 05 2005Two measures of entanglement, negativity and concurrence are studied for two arbitrary qudits. We obtain negativity as an expectation value of an operator. The differences of the squares of negativity and concurrence are invariants of multilevel entanglement. ... More