Results for "Nikhil Mehta"

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Improving Natural Language Interaction with Robots Using AdviceMay 12 2019Over the last few years, there has been growing interest in learning models for physically grounded language understanding tasks, such as the popular blocks world domain. These works typically view this problem as a single-step process, in which a human ... More
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
Robust and Fast 3D Scan Alignment using Mutual InformationSep 20 2017This paper presents a mutual information (MI) based algorithm for the estimation of full 6-degree-of-freedom (DOF) rigid body transformation between two overlapping point clouds. We first divide the scene into a 3D voxel grid and define simple to compute ... More
Koszul complexes, Birkhoff normal form and the magnetic Dirac operatorNov 27 2015We consider the semi-classical Dirac operator coupled to a magnetic potential on a large class of manifolds including all metric contact manifolds. We prove a sharp local Weyl law and a bound on its eta invariant. In the absence of a Fourier integral ... More
On a generalization of iterated and randomized roundingNov 05 2018Apr 10 2019We give a general method for rounding linear programs that combines the commonly used iterated rounding and randomized rounding techniques. In particular, we show that whenever iterated rounding can be applied to a problem with some slack, there is a ... More
Constructive Algorithms for Discrepancy MinimizationFeb 11 2010Aug 09 2010Given a set system (V,S), V={1,...,n} and S={S1,...,Sm}, the minimum discrepancy problem is to find a 2-coloring of V, such that each set is colored as evenly as possible. In this paper we give the first polynomial time algorithms for discrepancy minimization ... More
Multi-Band Feeds: A Design StudyOct 11 2012Broadband antenna feeds are of particular interest to existing and future radio telescopes for multi-frequency studies of astronomical sources. Although a 1:15 range in frequency is difficult to achieve, the well-known Eleven feed design offers a relatively ... More
Numerical Polynomial Homotopy Continuation Method and String VacuaAug 04 2011Dec 14 2011Finding vacua for the four dimensional effective theories for supergravity which descend from flux compactifications and analyzing them according to their stability is one of the central problems in string phenomenology. Except for some simple toy models, ... More
A New Push-Relabel Algorithm for Sparse NetworksOct 29 2013Jun 10 2014In this paper, we present a new push-relabel algorithm for the maximum flow problem on flow networks with $n$ vertices and $m$ arcs. Our algorithm computes a maximum flow in $O(mn)$ time on sparse networks where $m = O(n)$. To our knowledge, this is the ... More
Hodge structure on the cohomology of the moduli space of Higgs bundlesDec 12 2001Nov 27 2002We study the moduli space of Higgs bundles on a compact Riemann surface. It was shown by Thaddeus and Hausel (in rank 2) and Markman (in general rank) that the rational cohomology ring of this space is generated by universal classes. In this paper, we ... More
Constant Rank Bimatrix Games are PPAD-hardFeb 14 2014Mar 22 2014The rank of a bimatrix game (A,B) is defined as rank(A+B). Computing a Nash equilibrium (NE) of a rank-$0$, i.e., zero-sum game is equivalent to linear programming (von Neumann'28, Dantzig'51). In 2005, Kannan and Theobald gave an FPTAS for constant rank ... More
Max-Flows on Sparse and Dense NetworksSep 10 2013Oct 29 2013In this paper, we present an improved algorithm for the maximum flow problem on general networks with $n$ vertices and $m$ arcs. We show how to solve the problem in $O(mn)$ time, when $m = O(n^{2-\epsilon})$, for some $0 <\epsilon \leq 1$. This improves ... More
Birational equivalence of Higgs moduliNov 07 2003Nov 20 2003In this paper, we study triples of the form (E, theta, phi) over a compact Riemann Surface, where (E, theta) is a Higgs bundle and phi is a global holomorphic section of the Higgs bundle. Our main result is a description of a birational equivalence which ... More
A Simple Application of Enriques-Severi-Zariski-Serre to the Local Fundamental Group SchemeJan 01 2007Oct 04 2011We prove that Local Fundamental Group Scheme satisfies the conditions of Lefschetz-Bott-Grothendieck.
Storing and retrieving long-term memories: cooperation and competition in synaptic dynamicsJul 23 2018We first review traditional approaches to memory storage and formation, drawing on the literature of quantitative neuroscience as well as statistical physics. These have generally focused on the fast dynamics of neurons; however, there is now an increasing ... More
Sparse Transfer Learning via Winning Lottery TicketsMay 19 2019The recently proposed Lottery Ticket Hypothesis of Frankle and Carbin (2019) suggests that the performance of over-parameterized deep networks is due to the random initialization seeding the network with a small fraction of favorable weights. These weights ... More
External Photoevaporation of the Solar Nebula: Jupiter's Noble Gas EnrichmentsOct 17 2014We present a model explaining elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne and O are depleted, seven other elements show similar enrichments ($\sim$3 times solar, relative to H). Being volatile, ... More
Algorithmic Discrepancy Beyond Partial ColoringNov 06 2016The partial coloring method is one of the most powerful and widely used method in combinatorial discrepancy problems. However, in many cases it leads to sub-optimal bounds as the partial coloring step must be iterated a logarithmic number of times, and ... More
The Goldstone Equivalence Theorem and AdS/CFTFeb 11 2015The Goldstone equivalence theorem allows one to relate scattering amplitudes of massive gauge fields to those of scalar fields in the limit of large scattering energies. We generalize this theorem under the framework of the AdS/CFT correspondence. First, ... More
Including parameter dependence in the data and covariance for cosmological inferenceAug 03 2015Jan 05 2016The final step of most large-scale structure analyses involves the comparison of power spectra or correlation functions to theoretical models. It is clear that the theoretical models have parameter dependence, but frequently the measurements and the covariance ... More
Algorithmic Discrepancy Beyond Partial ColoringNov 06 2016Jul 11 2017The partial coloring method is one of the most powerful and widely used method in combinatorial discrepancy problems. However, in many cases it leads to sub-optimal bounds as the partial coloring step must be iterated a logarithmic number of times, and ... More
Tree-width and Logspace: Determinants and Counting Euler ToursDec 28 2013Dec 31 2013Motivated by the recent result of [EJT10] showing that MSO properties are Logspace computable on graphs of bounded tree-width, we consider the complexity of computing the determinant of the adjacency matrix of a bounded tree-width graph and prove that ... More
Energy Aware, Scalable, K-Hop Based Cluster Formation In MANETSep 21 2012The study of Mobile Ad-hoc Network remains attractive due to the desire to achieve better performance and scalability. MANETs are distributed systems consisting of mobile hosts that are connected by multi-hop wireless links. Such systems are self organized ... More
Cryptanalysis of a Chaotic Image Encryption AlgorithmJan 01 2008Jan 12 2008Line map, an invertible, two-dimensional chaotic encryption algorithm was introduced recently. In this paper, we propose several weaknesses of the method based on standard cryptanalytic attacks. We perform a side-channel attack by observing the execution ... More
Generating Simulations of Motion Events from Verbal DescriptionsOct 06 2016In this paper, we describe a computational model for motion events in natural language that maps from linguistic expressions, through a dynamic event interpretation, into three-dimensional temporal simulations in a model. Starting with the model from ... More
Designing Optimal Binary Rating SystemsJun 18 2018Apr 07 2019Modern online platforms rely on effective rating systems to learn about items. We consider the optimal design of rating systems that collect binary feedback after transactions. We make three contributions. First, we formalize the performance of a rating ... More
Robot Autonomy for SurgeryJul 10 2017Autonomous surgery involves having surgical tasks performed by a robot operating under its own will, with partial or no human involvement. There are several important advantages of automation in surgery, which include increasing precision of care due ... More
Asymptotically Optimal Multi-PavingJun 12 2017Aug 23 2017Anderson's paving conjecture, now known to hold due to the resolution of the Kadison-Singer problem asserts that every zero diagonal Hermitian matrix admits non-trivial pavings with dimension independent bounds. In this paper, we develop a technique extending ... More
Spectral weight in Chern-Simons theory with symmetry breakingMay 17 2019We calculate the low-energy spectral weight of a holographic superfluid coupled to a Chern-Simons term in IR radial scaling geometries characterized by a parameter $\eta$. This work was motivated by previous results where an unexpected low-energy spectral ... More
Approximation-Friendly Discrepancy RoundingDec 07 2015Rounding linear programs using techniques from discrepancy is a recent approach that has been very successful in certain settings. However this method also has some limitations when compared to approaches such as randomized and iterative rounding. We ... More
Evaluating the Performance of Offensive Linemen in the NFLMar 24 2016Apr 10 2016How does one objectively measure the performance of an individual offensive lineman in the NFL? The existing literature proposes various measures that rely on subjective assessments of game film, but has yet to develop an objective methodology to evaluate ... More
VoxML: A Visualization Modeling LanguageOct 05 2016We present the specification for a modeling language, VoxML, which encodes semantic knowledge of real-world objects represented as three-dimensional models, and of events and attributes related to and enacted over these objects. VoxML is intended to overcome ... More
Situational Grounding within Multimodal SimulationsFeb 05 2019In this paper, we argue that simulation platforms enable a novel type of embodied spatial reasoning, one facilitated by a formal model of object and event semantics that renders the continuous quantitative search space of an open-world, real-time environment ... More
A Bayesian Model of Multilingual Unsupervised Semantic Role InductionMar 04 2016We propose a Bayesian model of unsupervised semantic role induction in multiple languages, and use it to explore the usefulness of parallel corpora for this task. Our joint Bayesian model consists of individual models for each language plus additional ... More
Stability of the Kepler-11 System and its OriginAug 29 2014A significant fraction of Kepler systems are closely-packed, largely coplanar and circular. We study the stability of a 6-planet system, Kepler-11, to gain insights on the dynamics and formation history of such systems. Using a technique called `frequency ... More
On Event Triggered Tracking for Nonlinear SystemsJan 05 2013In this paper we study an event based control algorithm for trajectory tracking in nonlinear systems. The desired trajectory is modelled as the solution of a reference system with an exogenous input and it is assumed that the desired trajectory and the ... More
Content Replication in Large Distributed CachesMar 30 2016In this paper, we consider the algorithmic task of content replication and request routing in a distributed caching system consisting of a central server and a large number of caches, each with limited storage and service capabilities. We study a time-slotted ... More
Designing Optimal Binary Rating SystemsJun 18 2018Oct 28 2018Modern online platforms rely on effective rating systems to learn about items. We consider the optimal design of rating systems that collect {\em binary feedback} after transactions. We make three contributions. First, we formalize the performance of ... More
Calibrating the Baryon Oscillation Ruler for Matter and HalosJun 05 2009Sep 10 2009We characterize the nonlinear evolution of the baryon acoustic feature as traced by the dark matter and halos, using a combination of perturbation theory and N-body simulations. We confirm that the acoustic peak traced by the dark matter is both broadened ... More
Constraining Anisotropic Baryon OscillationsApr 05 2008We present an analysis of anisotropic baryon acoustic oscillations and elucidate how a mis-estimation of the cosmology, which leads to incorrect values of the angular diameter distance, d_A, and Hubble parameter, H, manifest themselves in changes to the ... More
The Geometry of SchedulingAug 28 2010We consider the following general scheduling problem: The input consists of n jobs, each with an arbitrary release time, size, and a monotone function specifying the cost incurred when the job is completed at a particular time. The objective is to find ... More
Bounded Treewidth and Space-Efficient Linear AlgebraDec 08 2014Motivated by a recent result of Elberfeld, Jakoby and Tantau showing that $\mathsf{MSO}$ properties are Logspace computable on graphs of bounded tree-width, we consider the complexity of computing the determinant of the adjacency matrix of a bounded tree-width ... More
Bochner Laplacian and Bergman kernel expansion of semi-positive line bundles on a Riemann surfaceNov 02 2018We generalize the results of Montgomery for the Bochner Laplacian on high tensor powers of a line bundle. When specialized to Riemann surfaces, this leads to the Bergman kernel expansion and geometric quantization results for semi-positive line bundles ... More
A Universal Parallel Two-Pass MDL Context Tree Compression AlgorithmJul 06 2014Mar 21 2015Computing problems that handle large amounts of data necessitate the use of lossless data compression for efficient storage and transmission. We present a novel lossless universal data compression algorithm that uses parallel computational units to increase ... More
Matched filtering with interferometric 21cm experimentsMay 26 2017Jul 05 2017A new generation of interferometric instruments is emerging which aim to use intensity mapping of redshifted $21\,$cm radiation to measure the large-scale structure of the Universe at $z\simeq 1-2$ over wide areas of sky. While these instruments typically ... More
Minimizing Flow-Time on Unrelated MachinesJan 28 2014Jun 09 2015We consider some flow-time minimization problems in the unrelated machines setting. In this setting, there is a set of $m$ machines and a set of $n$ jobs, and each job $j$ has a machine dependent processing time of $p_{ij}$ on machine $i$. The flow-time ... More
Complexity Bounds for the Controllability of Temporal Networks with Conditions, Disjunctions, and UncertaintyJan 08 2019In temporal planning, many different temporal network formalisms are used to model real world situations. Each of these formalisms has different features which affect how easy it is to determine whether the underlying network of temporal constraints is ... More
No evidence for bilinear condensate in parity-invariant three-dimensional QED with massless fermionsDec 09 2015Feb 04 2016We present our numerical study of three-dimensional QED with 2, 4, 6 and 8 flavors of massless two-component fermions using a parity-preserving lattice regularization with Wilson fermions. We study the behavior of low-lying eigenvalues of the massless ... More
The equation of state of two dimensional Yang-Mills theoryNov 10 2014We study the pressure, $P$, of SU($N$) gauge theory on a two-dimensional torus as a function of area, $A=l/t$. We find a cross-over scale that separates the system on a large circle from a system on a small circle at any finite temperature. The cross-over ... More
Privacy of Agents' Costs in Peer-to-Peer Distributed OptimizationMay 01 2019In this paper, we propose a protocol that preserves (statistical) privacy of agents' costs in peer-to-peer distributed optimization against a passive adversary that corrupts certain number of agents in the network. The proposed protocol guarantees privacy ... More
A 2% Distance to z = 0.35 by Reconstructing Baryon Acoustic Oscillations - III : Cosmological Measurements and InterpretationFeb 01 2012Mar 28 2012We use the 2% distance measurement from our reconstructed baryon acoustic oscillations (BAOs) signature using the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) Luminous Red Galaxies (LRGs) from Padmanabhan et al. (2012) and Xu et al. (2012) combined ... More
A Market for Scheduling, with Applications to Cloud ComputingNov 27 2015We present a market for allocating and scheduling resources to agents who have specified budgets and need to complete specific tasks. Two important aspects required in this market are: (1) agents need specific amounts of each resource to complete their ... More
A Review Paper on Oculus Rift-A Virtual Reality HeadsetAug 06 2014Oculus rift: Virtual reality (VR) is a burgeoning field that has the inherent potential of manipulating peoples mind with a superlative 3D experience. Oculus rift is one such application that assists in achieving the same. With the fleeting enhancements ... More
A 2% Distance to z=0.35 by Reconstructing Baryon Acoustic Oscillations - II: Fitting TechniquesFeb 01 2012Feb 04 2012We present results from fitting the baryon acoustic oscillation (BAO) signal in the correlation function obtained from the first application of reconstruction to a galaxy redshift survey, namely, the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) ... More
Faster Space-Efficient Algorithms for Subset Sum, k-Sum and Related ProblemsDec 08 2016Jun 24 2017We present space efficient Monte Carlo algorithms that solve Subset Sum and Knapsack instances with $n$ items using $O^*(2^{0.86n})$ time and polynomial space, where the $O^*(\cdot)$ notation suppresses factors polynomial in the input size. Both algorithms ... More
RTSPM: Real-time Linux control software for scanning probe microscopyOct 25 2012Dec 12 2012Real time computer control is an essential feature of scanning probe microscopes, which have become essential tools for the characterization and investigation of nanometer scale samples. Most commercial (and some open-source) scanning probe data acquisition ... More
Minimizing Higgs Potentials via Numerical Polynomial Homotopy ContinuationMar 02 2012The study of models with extended Higgs sectors requires to minimize the corresponding Higgs potentials, which is in general very difficult. Here, we apply a recently developed method, called numerical polynomial homotopy continuation (NPHC), which guarantees ... More
Nonequilibrium quantum-impurities: from entropy production to information theoryMay 31 2007Jun 08 2007Nonequilibrium steady-state currents, unlike their equilibrium counterparts, continuously dissipate energy into their physical surroundings leading to entropy production and time-reversal symmetry breaking. This letter discusses these issues in the context ... More
Scattering approach to impurity thermodynamicsFeb 26 2007Feb 26 2007Recently the authors developed a scattering approach that allows for a complete description of the steady-state physics of quantum-impurities in and out of equilibrium. Quantum impurities are described using scattering eigenstates defined ab initio on ... More
Lie algebroid modules and representations up to homotopyJul 07 2011Sep 08 2014We establish a relationship between two different generalizations of Lie algebroid representations: representation up to homotopy and Vaintrob's Lie algebroid modules. Specifically, we show that there is a noncanonical way to obtain a representation up ... More
Supergroupoids, double structures, and equivariant cohomologyMay 14 2006Q-groupoids and Q-algebroids are, respectively, supergroupoids and superalgebroids that are equipped with compatible homological vector fields. These new objects are closely related to the double structures of Mackenzie; in particular, we show that Q-groupoids ... More
An Efficient Local Strategy to Control Information Spreading in NetworkSep 26 2015In social networks, control of rumor spread is an active area of research. SIR model is generally used to study the rumor dynamics in network while considering the rumor as an epidemic. In disease spreading model, epidemic is controlled by removing central ... More
Anatomy of Cosmic Tidal ReconstructionApr 02 201921-cm intensity surveys aim to map neutral hydrogen atoms in the universe through hyper-fine emission. Unfortunately, long-wavelength (low-wavenumber) radial modes are highly contaminated by smooth astrophysical foregrounds that are six orders of magnitude ... More
Disentangling Language and Knowledge in Task-Oriented DialogsMay 03 2018Apr 05 2019The Knowledge Base (KB) used for real-world applications, such as booking a movie or restaurant reservation, keeps changing over time. End-to-end neural networks trained for these task-oriented dialogs are expected to be immune to any changes in the KB. ... More
Sub-leading asymptotics of ECH capacitiesNov 01 2018In previous work, the first author and collaborators showed that the leading asymptotics of the embedded contact homology (ECH) spectrum recovers the contact volume. Our main theorem here is a new bound on the sub-leading asymptotics.
Weak Lensing Constraints on Cluster Structural ParametersDec 12 2000We study the reliability of dark matter (DM) profile determinations for rich clusters of galaxies based on weak gravitational lensing measurements. We consider three functional forms for the mass distribution: a softened isothermal sphere (SIS), the Navarro, ... More
Detecting Dark Matter Annihilation with CMB Polarization : Signatures and Experimental ProspectsMar 23 2005Dark matter (DM) annihilation during hydrogen recombination (z ~ 1000) will alter the recombination history of the Universe, and affect the observed CMB temperature and polarization fluctuations. Unlike other astrophysical probes of DM, this is free of ... More
Linear Contextual Bandits with KnapsacksJul 24 2015Jul 09 2016We consider the linear contextual bandit problem with resource consumption, in addition to reward generation. In each round, the outcome of pulling an arm is a reward as well as a vector of resource consumptions. The expected values of these outcomes ... More
Zeros of some bi-orthogonal polynomialsSep 04 2001Ercolani and McLaughlin have recently shown that the zeros of the bi-orthogonal polynomials with the weight $w(x,y)=\exp[-(V_1(x)+V_2(y)+2cxy)/2]$, relevant to a model of two coupled hermitian matrices, are real and simple. We show that their argument ... More
Region Graph Based Method for Multi-Object Detection and Tracking using Depth CamerasMar 11 2016In this paper, we propose a multi-object detection and tracking method using depth cameras. Depth maps are very noisy and obscure in object detection. We first propose a region-based method to suppress high magnitude noise which cannot be filtered using ... More
Stack Exchange TaggerDec 13 2015The goal of our project is to develop an accurate tagger for questions posted on Stack Exchange. Our problem is an instance of the more general problem of developing accurate classifiers for large scale text datasets. We are tackling the multilabel classification ... More
Efficient Tracking of a Moving Object using Inter-Frame CodingMay 17 2014Video surveillance has long been in use to monitor security sensitive areas such as banks, department stores, highways, crowded public places and borders.The advance in computing power, availability of large-capacity storage devices and high speed network ... More
Identifying feasible operating regimes for early T-cell recognition: The speed, energy, accuracy trade-off in kinetic proofreading and adaptive sortingMar 09 2017Aug 16 2018In the immune system, T cells can quickly discriminate between foreign and self ligands with high accuracy. There is evidence that T-cells achieve this remarkable performance utilizing a network architecture based on a generalization of kinetic proofreading ... More
Stueckelberg Bosons as an Ultralight Dark Matter CandidateFeb 23 2019In this letter, we propose a new model of fuzzy dark matter based on Stueckelberg theory. Dark matter is treated as a Bose-Einstein condensate of Stueckelberg particles and the resulting cosmological effects are analyzed. Fits are understood for the density ... More
Infrared Effects and the Soft Photon Theorem in Massive QEDOct 24 2018Stueckelberg QED with massive photon is known to be renormalizable. But the limit of the mass going to zero is interesting because it brings the resolution to infrared questions through the role of Stueckelberg field at null infinity in addition to providing ... More
On-Line Balancing of Random InputsMar 16 2019We consider an online vector balancing game where vectors $v_t$, chosen uniformly at random in $\{-1,+1\}^n$, arrive over time and a sign $x_t \in \{-1,+1\}$ must be picked immediately upon the arrival of $v_t$. The goal is to minimize the $L^\infty$ ... More
The Solution of the Kadison-Singer ProblemDec 24 2017These lecture notes are meant to accompany two lectures given at the CDM 2016 conference, about the Kadison-Singer Problem. They are meant to complement the survey by the same authors (along with Spielman) which appeared at the 2014 ICM. In the first ... More
R-Estimation for Asymmetric Independent Component AnalysisApr 10 2013Dec 13 2013Independent Component Analysis (ICA) recently has attracted attention in the statistical literature as an alternative to elliptical models. Whereas k-dimensional elliptical densities depend on one single unspecified radial density, however, k-dimensional ... More
A real-time software simulator for scanning force microscopyJul 29 2013Sep 08 2014We describe software that simulates the hardware of a scanning force microscope. The essential feature of the software is its real-time response, which is critical for mimicking the behavior of real scanning probe hardware. The simulator runs on an open-source ... More
A Hybrid Analog/Digital Phase-Locked Loop for Frequency Mode Non-contact Scanning Probe MicroscopyJul 30 2013Jul 31 2013Non-contact scanning probe microscopy (SPM) has developed into a powerful technique to image many different properties of samples. The conventional method involves monitoring the amplitude, phase or frequency of a cantilever oscillating at or near its ... More
Non-standard interactions spoiling the CP violation sensitivity at DUNE and other long baseline experimentsMar 04 2016Jul 12 2016It is by now established that neutrino oscillations occur due to non-zero masses and parameters in the leptonic mixing matrix. The extraction of oscillation parameters may be complicated due to subleading effects such as non-standard neutrino interactions ... More
Interplay of energy dependent astrophysical neutrino flavor ratios and new physics effectsJan 13 2011Mar 25 2011We discuss the importance of flavor ratio measurements in neutrino telescopes, such as by measuring the ratio between muon tracks to cascades, for the purpose of extracting new physics signals encountered by astrophysical neutrinos during propagation ... More
Light $U(1)$s in heterotic string modelsMar 16 2015We present a novel string-derived $U(1)$ combination that satisfies necessary properties to survive to low scales. We discuss previous attempts at acquiring such an abelian gauge symmetry from two different string embeddings and the pitfalls associated ... More
Rationality of the instability parabolic and related resultsNov 11 2011In this paper we study the extension of structure group of principal bundles with a reductive algebraic group as structure group on smooth projective varieties defined over algebraically closed field of positive characteristic. Our main result is to show ... More
An index-resolved fixed-point homotopy and potential energy landscapesApr 24 2015Stationary points (SPs) of the potential energy landscapes can be classified by their Morse index, i.e., the number of negative eigenvalues of the Hessian evaluated at the SPs. In understanding chemical clusters through their potential energy landscapes, ... More
The Storage-Repair-Bandwidth Trade-off of Exact Repair Linear Regenerating Codes for the Case $d = k = n-1$Jan 16 2015Jan 26 2015In this paper, we consider the setting of exact repair linear regenerating codes. Under this setting, we derive a new outer bound on the storage-repair-bandwidth trade-off for the case when $d = k = n -1$, where $(n, k, d)$ are parameters of the regenerating ... More
Regrasping by Fixtureless FixturingSep 23 2018Sep 25 2018This paper presents a fixturing strategy for regrasping that does not require a physical fixture. To regrasp an object in a gripper, a robot pushes the object against external contact/s in the environment such that the external contact keeps the object ... More
Stable Prehensile Pushing: In-Hand Manipulation with Alternating Sticking ContactsOct 30 2017Mar 04 2018This paper presents an approach to in-hand manipulation planning that exploits the mechanics of alternating sticking contact. Particularly, we consider the problem of manipulating a grasped object using external pushes for which the pusher sticks to the ... More
Bandits with concave rewards and convex knapsacksFeb 24 2014In this paper, we consider a very general model for exploration-exploitation tradeoff which allows arbitrary concave rewards and convex constraints on the decisions across time, in addition to the customary limitation on the time horizon. This model subsumes ... More
Geometric Phase in a Bose-Einstein Josephson JunctionJul 03 2003Jul 04 2003We calculate the geometric phase associated with the time evolution of the wave function of a Bose-Einstein condensate system in a double-well trap by using a model for tunneling between the wells. For a cyclic evolution, this phase is shown to be half ... More
Fundamental Limits of Video Coding: A Closed-form Characterization of Rate Distortion Region from First PrinciplesFeb 27 2014Classical motion-compensated video coding methods have been standardized by MPEG over the years and video codecs have become integral parts of media entertainment applications. Despite the ubiquitous use of video coding techniques, it is interesting to ... More
Non-standard interactions and the resolution of ordering of neutrino masses at DUNE and other long baseline experimentsJun 17 2016Sep 10 2016In the era of precision neutrino physics, we study the influence of matter NSI on the question of neutrino mass ordering and its resolution. At long baseline experiments, since matter effects play a crucial role in addressing this very important question, ... More
Generation of non-classical states of photons from metal-dielectric interface: a novel architecture for quantum information processingSep 09 2018We show that it is possible to generate photons in nonclassical states from a metal-dielectric interface using quantum emitters on the interface. The photons emitted into the surface plasmon mode from the initially excited emitters radiate out in free ... More
L-infinity algebra actionsFeb 13 2012Aug 30 2012We define the notion of action of an L-infinity algebra $g$ on a graded manifold $M$, and show that such an action corresponds to a homological vector field on $g[1] \times M$ of a specific form. This generalizes the correspondence between Lie algebra ... More
Modular Classes of Lie Groupoid Representations up to HomotopyFeb 22 2015Jul 25 2015We describe a construction of the modular class associated to a representation up to homotopy of a Lie groupoid. In the case of the adjoint representation up to homotopy, this class is the obstruction to the existence of a volume form, in the sense of ... More
Vector Bundles over Normal Varieties Trivialized by Finite MorphismsSep 27 2010Let $Y$ be a normal and projective variety over an algebraically closed field $k$ and $V$ a vector bundle over $Y$. We prove that if there exist a $k$-scheme $X$ and a finite surjective morphism $g:X\to Y$ that trivializes $V$ then $V$ is essentially ... More
Weak Density of the Fundamental Group SchemeNov 09 2009On $X$ projective smooth over an algebraically closed field, we show that if Nori's fundamental group scheme is trivial, then there are no nontrivial Nori semistable bundles of degree 0, that is the group scheme $\pi^S(X)$ studied in particular by Langer ... More
Semistability of Frobenius direct images over curvesJul 22 2006Let $X$ be a smooth projective curve of genus $g \geq 2$ defined over an algebraically closed field $k$ of characteristic $p>0$. Given a semistable vector bundle $E$ over $X$, we show that its direct image $F\_*E$ under the Frobenius map $F$ of $X$ is ... More
On the Network Topology Dependent Solution Count of the Algebraic Load Flow EquationsDec 15 2015A large amount of research activity in power systems areas has focused on developing computational methods to solve load flow equations where a key question is the maximum number of isolated solutions.Though several concrete upper bounds exist, recent ... More
Parallel degree computation for solution space of binomial systems with an application to the master space of $\mathcal{N}=1$ gauge theoriesJan 09 2015Mar 01 2015The problem of solving a system of polynomial equations is one of the most fundamental problems in applied mathematics. Among them, the problem of solving a system of binomial equations form a important subclass for which specialized techniques exist. ... More