Results for "P. Mitra"

total 113059took 0.13s
Complex fermion mass term, regularization and CP violationMay 18 2007It is well known that the CP violating theta term of QCD can be converted to a phase in the quark mass term. However, a theory with a complex mass term for quarks can be regularized so as not to violate CP, for example through a zeta function. The contradiction ... More
Hawking temperature from tunnelling formalismNov 24 2006Mar 05 2007It has recently been suggested that the attempt to understand Hawking radiation as tunnelling across black hole horizons produces a Hawking temperature double the standard value. It is explained here how one can obtain the standard value in the same tunnelling ... More
Strong CP: No ProblemApr 07 2005Detailed analysis shows that the phase of a complex mass term of a quark does not violate CP, while the QCD vacuum angle can naturally be set equal to zero. There is no strong CP problem and no need for axions or similar speculative constructions to be ... More
Chiral phase in fermionic measure and the resolution of the strong CP problemApr 23 2001May 08 2001The fermionic measure in the functional integral of a gauge theory suffers from an ambiguity in the form of a chiral phase. By fixing it, one is led once again to the conclusion that a chiral phase in the quark mass term of QCD has no effect and cannot ... More
Entropy of extremal black holes in asymptotically anti-de Sitter spacetimeJul 14 1998Dec 16 1999Unlike the extremal Reissner - Nordstr\"{o}m black hole in ordinary spacetime, the one in anti-de Sitter spacetime is a minimum of action and has zero entropy if quantization is carried out after extremalization. However, if extremalization is carried ... More
Zeta function regularization, anomaly and complex mass termMar 04 2011Jun 01 2012If the zeta function regularization is used and a complex mass term considered for fermions, the phase does not appear in the fermion determinant. This is not a drawback of the regularization, which can recognize the phase through source terms, as demonstrated ... More
Time-reversal and parity conservation for gravitating quarksMar 03 2009Mar 09 2009The complex mass term of a quark does not violate time-reversal or parity in gravitational interactions, in spite of an axial anomaly.
Thermodynamics of charged anti-de Sitter black holes in canonical ensembleMar 20 1999Dec 16 1999As in the grand canonical treatment of Reissner - Nordstr\"{o}m black holes in anti-de Sitter spacetime, the canonical ensemble formulation also shows that non-extremal black holes tend to have lower action than extremal ones. However, some small non-extremal ... More
Black hole state counting in loop quantum gravityMay 25 2007Jun 26 2009Counting of microscopic states of black holes is discussed within the framework of loop quantum gravity. There are two different ways, one allowing for all spin states and the other involving only pure horizon states. The number of states with a definite ... More
Estimate Exchange over Network is Good for Distributed Hard Thresholding PursuitSep 22 2017We investigate an existing distributed algorithm for learning sparse signals or data over networks. The algorithm is iterative and exchanges intermediate estimates of a sparse signal over a network. This learning strategy using exchange of intermediate ... More
Understanding CP violation in lattice QCDFeb 20 2001Sep 12 2002It is pointed out that any CP violation which may be found in lattice QCD with a chiral phase in the fermion mass term cannot be relevant for the continuum theory. CP is classically conserved in the corresponding continuum theory and is non-anomalous. ... More
Exclusion statistics and many-particle statesNov 30 1994The thermodynamic distribution function for exclusion statistics is derived. Creation and annihilation operators for particles obeying such statistics are discussed. A connection with anyons is pointed out.
Subtleties of the fermion measure in the presence of axion fieldsFeb 03 2015May 01 2015It is known from path integral studies of the chiral anomaly that the fermion measure has to depend on gauge fields interacting with the fermion. It is pointed out here that in the presence of an axion field interacting with the fermion, it too is involved ... More
Black hole entropy with and without log correction in loop quantum gravityJun 02 2014Earlier calculations of black hole entropy in loop quantum gravity have given a term proportional to the area with a correction involving the logarithm of the area when the area eigenvalue is close to the classical area. However the calculations yield ... More
Theories with global gauge anomalies on the latticeOct 03 2000A global anomaly in a chiral gauge theory manifests itself in different ways in the continuum and on the lattice. In the continuum case, functional integration of the fermion determinant over the whole space of gauge fields yields zero. In the case of ... More
Quantization of Gauge Theories with AnomaliesJun 23 1995In this talk, we briefly review the basic concepts of anomalous gauge theories. It has been known for some time how theories with local anomalies can be handled. Recently it has been pointed out that global anomalies, which obstruct the quantization of ... More
Black hole entropy: departures from area lawMar 23 1995The thermodynamic and euclidean functional integral approaches to black hole entropy are discussed. The existence of some freedom in the definition of the entropy is pointed out and the possibility of a departure from the semiclassical expression discussed ... More
Structure of Multi-Anyon WavefunctionsDec 13 1993Symmetries of multi-anyon wavefunctions are analysed with the help of a second quantized formulation. Analogues of Slater determinants are constructed. It is shown that the Pauli principle is not enforced.
T invariance of Higgs interactions in the standard modelMar 21 2003In the standard model, the Cabibbo-Kobayashi-Maskawa matrix, which incorporates the time-reversal violation shown by the charged current weak interactions, originates from the Higgs-quark interactions. The Yukawa interactions of quarks with the physical ... More
Entropy of near-extremal dyonic black holesDec 30 1997Jan 19 1998In this note it is shown that near-extremal four dimensional dyonic black holes, where the dilaton is not constant, can be described by a microscopic model consisting of a one-dimensional gas of massless particles.
Black Hole EntropyMar 28 1996Apr 04 1996Major developments in the history of the subject are critically reviewed in this talk.
Area law for black hole entropy in the SU(2) quantum geometry approachJul 22 2011May 16 2012Black hole thermodynamics suggests that a black hole should have an entropy given by a quarter of the area of its horizon. Earlier calculations in U(1) loop quantum gravity have led to a dominant term proportional to the area, but there was a correction ... More
Black hole entropyFeb 12 2009Mar 09 2009We review black hole entropy with special reference to euclidean quantum gravity, the brick wall approach and loop quantum gravity.
A note on the entropy of charged multi - black - holesAug 05 1999Majumdar--Papapetrou multi--black-hole solutions of the Einstein--Maxwell equations are considered in four and higher dimensions. The Euclidean action with boundary conditions appropriate to the canonical ensemble is shown to lead to zero entropy.
Entropy of extremal black holesApr 29 1997May 09 1997After summarizing the development of black hole thermodynamics in the seventies, we describe a recent microscopic model. This model suggests that the Bekenstein-Hawking area formula holds for extremal black holes as well as for ordinary (non-extremal) ... More
Quasi-reversible Magnetoresistance in Exchange Spring Tunnel JunctionsJul 17 2008We report a large, quasi-reversible tunnel magnetoresistance in exchange-biased ferromagnetic semiconductor tunnel junctions wherein a soft ferromagnetic semiconductor (\gma) is exchange coupled to a hard ferromagnetic metal (MnAs). Our observations are ... More
Spin Valve Effect in Self-exchange Biased Ferromagnetic Metal/Semiconductor BilayersAug 15 2007We report magnetization and magetoresistance measurements in hybrid ferromagnetic metal/semiconductor heterostructures comprised of MnAs/(Ga,Mn)As bilayers. Our measurements show that the (metallic) MnAs and (semiconducting) (Ga,Mn)As layers are exchange ... More
Regime Switching Stochastic Volatility with Perturbation Based Option PricingApr 10 2009Volatility modelling has become a significant area of research within Financial Mathematics. Wiener process driven stochastic volatility models have become popular due their consistency with theoretical arguments and empirical observations. However such ... More
On a Theorem of Scott and SwarupSep 19 2012Let $1 \rightarrow H \rightarrow G \rightarrow \mathbb{Z} \rightarrow 1$ be an exact sequence of hyperbolic groups induced by a fully irreducible automorphism $\phi$ of the free group $H$. Let $H_1 (\subset H)$ be a finitely generated distorted subgroup ... More
Hawking temperature and higher order calculationsFeb 02 2009Apr 09 2009Hawking radiation has recently been explained by using solutions of wave equations across black hole horizons in a WKB approximation. Higher order calculations using both usual and non-singular coordinates are found to change the solution for zero spin, ... More
Asymptotically non-flat rotating dilaton black holesDec 12 2002Mar 13 2003Dilaton black hole solutions which are neither asymptotically flat nor (anti)-de Sitter but reduce to asymptotically flat solutions in some special limits have been known for a Liouville type dilatonic potential. It is shown how, by solving a pair of ... More
Quantum correction to thermodynamical entropy of black holeJun 17 1997The entropy of a black hole can differ from a quarter of the area of the horizon because of quantum corrections. The correction is related to the contribution to the Euclidean functional integral from quantum fluctuations but is not simply equal to the ... More
Entropy of Extremal Black Hole Solutions of String TheorySep 15 1995Sep 29 1995For extremal black holes, the thermodynamic entropy is not proportional to the area. The general form allowed by thermodynamics is worked out for three classes of extremal black hole solutions of string theory and shown to be consistent with the entropy ... More
General form of thermodynamical entropy for black holeAug 31 1994Jun 17 1997The entropy of a black hole can be different from a quarter of the area even at the semiclassical level.
Fermion Scattering off Dilatonic Black HolesMay 02 1994The scattering of massless fermions off magnetically charged dilatonic black holes is reconsidered and a violation of unitarity is found. Even for a single species of fermion it is possible for a particle to disappear into the black hole with its information ... More
Non-commutative Oscillators and the commutative limitApr 18 2002Apr 24 2002It is shown in first order perturbation theory that anharmonic oscillators in non-commutative space behave smoothly in the commutative limit just as harmonic oscillators do. The non-commutativity provides a method for converting a problem in degenerate ... More
Patching up the monopole potentialDec 23 2003It is well known that a vector potential cannot be defined over the whole surface of a sphere around a magnetic monopole. A recent claim to the contrary is shown to have problems. It is explained however that a potential of the proposed type works if ... More
A comment on black hole state counting in loop quantum gravityMay 28 2008There are two ways of counting microscopic states of black holes in loop quantum gravity, one counting all allowed spin network labels $j,m$ and the other involving only the labels $m$. Counting states with $|m|=j$, as done in a recent Letter, does not ... More
On the log correction to the black hole area lawJan 16 2004Jul 15 2004Various approaches to black hole entropy yield the area law with logarithmic corrections, many involving a coefficient 1/2, and some involving 3/2. It is pointed out here that the standard quantum geometry formalism is not consistent with 3/2 and favours ... More
Quantum and classical areas of black hole thermodynamicsJun 23 2015Most calculations of black hole entropy in loop quantum gravity indicate a term proportional to the area eigenvalue A with a correction involving the logarithm of A. This violates the additivity of the entropy. An entropy proportional to A, with a correction ... More
Reply to comment by Zaslavskii on extremal black hole actionApr 20 1998It is shown that Zaslavskii's misunderstanding of our published proof of the irrelevance of all extremal black hole configurations (whether with equal charge and mass or not) rests on his refusal to see the essential difference between the correct inequality ... More
Entropy for extremal Reissner- Nordstrøm black holesNov 17 1994We reinterpret recent work on extremal Reissner- Nordstr\o m black holes to argue that the mass is a measure of the gravitational entropy. We also find that the entropy of scalar fields in this background has a stronger divergence than usual.
Entropy for dilatonic black holeJun 30 1994Jul 07 1994The area formula for entropy is extended to the case of a dilatonic black hole. The entropy of a scalar field in the background of such a black hole is calculated semiclassically. The area and cutoff dependences are normal {\it except in the extremal ... More
Regularizing tunnelling calculations of Hawking temperatureJul 07 2011Jun 01 2012Attempts to understand Hawking radiation as tunnelling across a black hole horizon require the consideration of singular integrals. Although Schwarzschild coordinates lead to the standard Hawking temperature, isotropic radial coordinates may appear to ... More
Bending a slab of neural tissueOct 17 2005Nov 08 2006In comparative and developmental neuroanatomy one encounters questions regarding the deformation of neural tissue under stress. The motivation of this note is an observation (Barbas {\it et al}) that at cortical folds or gyri, the layers of neural tissue ... More
Black hole state counting in loop quantum gravityMay 26 2011The two ways of counting microscopic states of black holes in the U(1) formulation of loop quantum gravity, one counting all allowed spin network labels j,m and the other only m labels, are discussed in some detail. The constraints on m are clarified ... More
Doubly-charged Higgs Boson at Future Electron-Proton ColliderMar 04 2019We explore the discovery prospect of the doubly-charged component of an $SU(2)_L$-triplet scalar at the future $e^- p$ collider FCC-eh, proposed to operate with an electron beam energy of 60 GeV and a proton beam energy of 50 TeV. We consider the associated ... More
Absence of log correction in entropy of large black holesJun 15 2012May 16 2014Earlier calculations of black hole entropy in loop quantum gravity led to a dominant term proportional to the area, but there was a correction involving the logarithm of the area, the Chern-Simons level being assumed to be large. We find that the calculations ... More
Counting of Black Hole MicrostatesMar 09 2006May 15 2006The entropy of a black hole can be obtained by counting states in loop quantum gravity. The dominant term depends on the Immirzi parameter involved in the quantization and is proportional to the area of the horizon, while there is a logarithmic correction ... More
Fine-grained state counting for black holes in loop quantum gravitySep 24 2008Mar 13 2009A state of a black hole in loop quantum gravity is given by a distribution of spins on punctures on the horizon. The distribution is of the Boltzmann type, with the area playing the role of the energy. In investigations where the total area was kept approximately ... More
Entropy of Extremal Dyonic Black HolesFeb 12 1996Aug 02 1996For extremal charged black holes, the thermodynamic entropy is proportional not to the area but to the mass or charges. This is demonstrated here for dyonic extremal black hole solutions of string theory. It is pointed out that these solutions have zero ... More
An improved estimate of black hole entropy in the quantum geometry approachNov 08 2004May 30 2005A proper counting of states for black holes in the quantum geometry approach shows that the dominant configuration for spins are distributions that include spins exceeding one-half at the punctures. This raises the value of the Immirzi parameter and the ... More
Counting black hole microscopic states in loop quantum gravityMay 12 2006Sep 12 2006Counting of microscopic states of black holes is performed within the framework of loop quantum gravity. This is the first calculation of the pure horizon states using statistical methods, which reveals the possibility of additional states missed in the ... More
Understanding the area proposal for extremal black hole entropyAug 30 1996Jan 15 1997Whereas the usual understanding is that the entropy of only a non-extremal black hole is given by the area of the horizon, there are derivations of an area law for extremal black holes in some model calculations. It is explained here how such results ... More
Temperatures of extremal black holesJul 14 1995The temperature of an extremal Reissner - Nordstrom black hole is not restricted by the requirement of absence of a conical singularity. It is demonstrated how Kruskal-like coordinates may be constructed corresponding to any temperature whatsoever. A ... More
Joint Atlas-Mapping of Multiple Histological Series combined with Multimodal MRI of Whole Marmoset BrainsMay 14 2018Development of a mesoscale neural circuitry map of the common marmoset is an essential task due to the ideal characteristics of the marmoset as a model organism for neuroscience research. To facilitate this development there is a need for new computational ... More
Idl Signal Processing Library 1.0Jan 20 1998We make available a library of documented IDL .pro files as well as a shareable object library that allows IDL to call routines from LAPACK. The routines are for use in the spectral analysis of time series data. The primary focus of these routines are ... More
Analysis of Dynamic Brain Imaging DataApr 20 1998Modern imaging techniques for probing brain function, including functional Magnetic Resonance Imaging, intrinsic and extrinsic contrast optical imaging, and magnetoencephalography, generate large data sets with complex content. In this paper we develop ... More
Marker Genes for Anatomical Regions in the Brain: Insights from the Allen Gene Expression AtlasMay 06 2011Quantitative criteria are proposed to identify genes (and sets of genes) whose expression marks a specific brain region (or a set of brain regions). Gene-expression energies, obtained for thousands of mouse genes by numerization of in-situ hybridization ... More
Algorithmic choice of coordinates for injections into the brain: encoding a neuroanatomical atlas on a gridApr 13 2011Given an atlas of the brain and a number of injections to be performed in order to map out the connections between parts of the brain, we propose an algorithm to compute the coordinates of the injections. The algorithm is designed to sample the brain ... More
Computational neuroanatomy and gene expression: optimal sets of marker genes for brain regionsMay 11 2012The three-dimensional data-driven Allen Gene Expression Atlas of the adult mouse brain consists of numerized in-situ hybridization data for thousands of genes, co-registered to the Allen Reference Atlas. We propose quantitative criteria to rank genes ... More
Statistical analysis of co-expression properties of sets of genes in the mouse brainNov 26 2011Dec 11 2011We propose a quantitative method to estimate the statistical properties of sets of genes for which expression data are available and co-registered to a reference atlas of the brain. It is based on graph-theoretic properties of co-expression coefficients ... More
StarL: Towards a Unified Framework for Programming, Simulating and Verifying Distributed Robotic SystemsFeb 22 2015We developed StarL as a framework for programming, simulating, and verifying distributed systems that interacts with physical processes. StarL framework has (a) a collection of distributed primitives for coordination, such as mutual exclusion, registration ... More
Visual saliency detection: a Kalman filter based approachApr 17 2016In this paper we propose a Kalman filter aided saliency detection model which is based on the conjecture that salient regions are considerably different from our "visual expectation" or they are "visually surprising" in nature. In this work, we have structured ... More
Relevance of Quantum Mechanics in Circuit Implementation of Ion channels in Brain DynamicsJun 08 2006With an increasing amount of experimental evidence pouring in from neurobiological investigations, it is quite appropriate to study viable reductionist models which may explain some of the features of brain activities. It is now quite well known that ... More
On The Transport Theory of Classical Gases in Rindler SpaceDec 30 2016Jan 16 2017We have obtained the Vlasov equation and Boltzmann kinetic equation using Poisson bracket (classical Hamilton equation) and Rindler Hamiltonian. Further, we treat the whole Universe as a statistical system with galaxies as the point particle constituents ... More
Classical Trajectories in Rindler Space and Restricted Structure of Phase SpaceOct 31 2015Aug 18 2016The nature of single particle classical phase space trajectories in Rindler space have been studied. It has been shown that only a small portion of the phase space is accessible to the particles, whereas the major part of the phase space region is completely ... More
Periodic Longitude-Stationary Non-Drift Emission in Core-Single Radio Pulsar B1946+35Mar 29 2017Radio pulsar PSR B1946+35 is a classical example of a core/cone triple pulsar where the observer's line-of-sight cuts the emission beam centrally. In this paper we perform a detailed single-pulse polarimetric analysis of B1946+35 using sensitive Arecibo ... More
Monodromy, liftings of holomorphic maps, and extensions of holomorphic motionsApr 11 2018We study monodromy of holomorphic motions and show the equivalence of triviality of monodromy of holomorphic motions and extensions of holomorphic motions to continuous motions of the Riemann sphere. We also study liftings of holomorphic maps into certain ... More
Orbital ordering in undoped manganites using Jahn-Teller interactionOct 15 2003To understand the orbital ordering of $LaMnO_3$ in the ground state, we study it in the A-type spin antiferromagnetic state. We calculate the two-dimensional response functions associated with the Jahn-Teller $Q_2$ and $Q_3$ distortions and find that ... More
Body-centered phase of shock loaded CuJul 21 2016Single crystal Cu when shock loaded in certain direction for a certain narrow range of piston velocities undergoes a structural phase transition from face-centered cubic to different body-centered phases. Based on molecular dynamic simulations, the manuscript ... More
Sampling Properties of the Spectrum and Coherency of Sequences of Action PotentialsFeb 29 2000The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This paper begins with a review of these quantities, their interpretation and how they may be estimated. ... More
Distributions of Singular Values for Some Random MatricesSep 25 1997The Singular Value Decomposition is a matrix decomposition technique widely used in the analysis of multivariate data, such as complex space-time images obtained in both physical and biological systems. In this paper, we examine the distribution of Singular ... More
Polaronic Heat Capacity in The Anderson - Hasegawa ModelJan 16 2003An exact treatment of the Anderson - Hasegawa two - site model, incorporating the presence of superexchange and polarons, is used to compute the heat capacity. The calculated results point to the dominance of the lattice contribution, especially in the ... More
A Generalized Gauge Invariant Regularization of the Schwinger ModelOct 21 1993The Schwinger model is studied with a new one - parameter class of gauge invariant regularizations that generalizes the usual point - splitting or Fujikawa schemes. The spectrum is found to be qualitatively unchanged, except for a limiting value of the ... More
Tunnelling from black holes and tunnelling into white holesApr 13 2007Feb 20 2008Hawking radiation is nowadays being understood as tunnelling through black hole horizons. Here, the extension of the Hamilton-Jacobi approach to tunnelling for non-rotating and rotating black holes in different non-singular coordinate systems not only ... More
T-Dependent Dyson- Schwinger Equation In IR Regime Of QCD: The Critical PointMar 14 2004Aug 23 2004The quark mass function $\Sigma(p)$ in QCD is revisited, using a gluon propagator in the form $1/(k^2 + m_g^2)$ plus $2\mu^2/ (k^2 + m_g^2)^2$, where the second (IR) term gives linear confinement for $m_g = 0$ in the instantaneous limit, $\mu$ being another ... More
Localization and the Anomalous Hall Effect in a "Dirty" Metallic FerromagnetAug 15 2008Jun 15 2010We report magnetoresistance measurements over an extensive temperature range (0.1 K $\leq T \leq$ 100 K) in a disordered ferromagnetic semiconductor (\gma). The study focuses on a series of metallic \gma~ epilayers that lie in the vicinity of the metal-insulator ... More
Cell-type-specific microarray data and the Allen atlas: quantitative analysis of brain-wide patterns of correlation and densityFeb 28 2013Oct 12 2013The Allen Atlas of the adult mouse brain is used to estimate the region-specificity of 64 cell types whose transcriptional profile in the mouse brain has been measured in microarray experiments. We systematically analyze the preliminary results presented ... More
Multidimensional Isotropic and Anisotropic Q-Oscillator ModelsNov 13 1995q-oscillator models are considered in two and higher dimensions and their symmetries are explored. New symmetries are found for both isotropic and anisotropic cases. Applications to the spectra of triatomic molecules and superdeformed nuclei are discussed. ... More
Statistical Entropy of Schwarzschild Black Strings and Black HolesMay 11 2000The statistical entropy of a Schwarzschild black string in five dimensions is obtained by counting the black string states which form a representation of the near-horizon conformal symmetry with a central charge. The statistical entropy of the string ... More
Just In Time IndexingAug 16 2013One of the major challenges being faced by Database managers today is to manage the performance of complex SQL queries which are dynamic in nature. Since it is not possible to tune each and every query because of its dynamic nature, there is a definite ... More
Computational neuroanatomy and co-expression of genes in the adult mouse brain, analysis tools for the Allen Brain AtlasJan 09 2013We review quantitative methods and software developed to analyze genome-scale, brain-wide spatially-mapped gene-expression data. We expose new methods based on the underlying high-dimensional geometry of voxel space and gene space, and on simulations ... More
Nonlinear limits to the information capacity of optical fiber communicationsNov 07 2000The exponential growth in the rate at which information can be communicated through an optical fiber is a key element in the so called information revolution. However, like all exponential growth laws, there are physical limits to be considered. The nonlinear ... More
Temperature Dependence of Gluon and Quark Condensates as from Linear ConfinementSep 28 2001Jan 08 2002The gluon and quark condensates and their temperature dependence are investigated within QCD premises. The input for the former is a gauge invariant $gg$ kernel made up of the direct (D), exchange (X) and contact(C) QCD interactions in the lowest order, ... More
Is there still a strong CP problem?Dec 21 2000Sep 16 2003The role of a chiral U(1) phase in the quark mass in QCD is analysed from first principles. In operator formulation, there is a parity symmetry and the phase can be removed by a change in the representation of the Dirac gamma matrices. Moreover, these ... More
Understanding Far-Infrared Absorption in the S=1 Antiferromagnetic Chain Compound NENPSep 17 1993Infrared transmission measurements on the $S=1$ antiferromagnetic chain compound NENP in applied magnetic fields show a sharp absorption line at the field-shifted Haldane gap. This violates a wave-vector selection rule of the Hamiltonian normally used ... More
Quantum Treatment of the Anderson-Hasegawa Model -- Effects of Superexchange and PolaronsApr 17 2002We revisit the Anderson-Hasegawa double-exchange model and critically examine its exact solution when the core spins are treated quantum mechanically.We show that the quantum effects, in the presence of an additional superexchange interaction between ... More
Filling factors and scale heights of the DIG in the Milky WayNov 07 2005The combination of dispersion measures of pulsars, distances from the model of Cordes and Lazio (2002) and emission measures from the WHAM survey enabled a statistical study of electron densities and filling factors of the diffuse ionized gas (DIG) in ... More
Toward An Empirical Theory of Pulsar Emission. VII. On the Spectral Behavior of Conal Beam Radii and Emission HeightsMay 21 2002In this paper we return to the old problem of conal component-pair widths and profile dimensions. Observationally, we consider a set of 10 pulsars with prominent conal component pairs, for which well measured profiles exist over the largest frequency ... More
Exploring Spatial Coherence in Inter-annual Changes and Annual Extremes of Rainfall over IndiaOct 26 2016Forecasts of monsoon rainfall for India are made at national scale. But there is spatial coherence and heterogeneity that is relevant to forecasting. This paper considers year-to-year rainfall change and annual extremes at sub-national scales. We use ... More
Hidden Regular Variation: Detection and EstimationJan 27 2010Sep 03 2010Hidden regular variation defines a subfamily of distributions satisfying multivariate regular variation on $\mathbb{E} = [0, \infty]^d \backslash \{(0,0, ..., 0) \} $ and models another regular variation on the sub-cone $\mathbb{E}^{(2)} = \mathbb{E} ... More
Entanglement properties of the time periodic Kitaev ChainMay 27 2017Aug 25 2017The entanglement properties of the time periodic Kitaev chain with nearest neighbor and next nearest neighbor hopping, is studied. The cases of the exact eigenstate of the time periodic Hamiltonian, referred to as the Floquet ground state (FGS), as well ... More
Understanding the Effect of Uniaxial Tensile Strain on the Early Stages of Sensitization in AISI 304 Austenitic Stainless SteelMar 07 2014In the present study, an attempt has been made to understand the effect of different competing mechanisms controlling the overall degree of sensitization (DOS) of deformed austenitic stainless steel at the early stage of sensitization. The Double Loop ... More
Toward an Empirical Theory of Pulsar Emission. IX. On the Peculiar Properties and Geometric Regularity of Lyne & Manchester's "Partial Cone" PulsarsNov 02 2010Lyne & Manchester (1988) identified a group of some 50 pulsars they called "partial cones" which they found difficult to classify and interpret. They were notable for their asymmetric average profiles and asymmetric polarization position-angle (PPA) traverses, ... More
On the Subpulse Modulation, Polarization and Subbeam Carousel Configuration of Pulsar B1857--26Dec 10 2007New GMRT observations of the five-component pulsar B1857--26 provide detailed insight into its pulse-sequence modulation phenomena for the first time. The outer conal components exhibit a 7.4-rotation-period, longitude-stationary modulation. Several lines ... More
Weak localization correction to the anomalous Hall effect in polycrystalline Fe filmsJun 08 2006May 22 2007In situ transport measurements have been made on ultrathin ($<$100 {\AA} thick) polycrystalline Fe films as a function of temperature and magnetic field for a wide range of disorder strengths. For sheet resistances $R_{xx}$ less than $\sim 3k\Omega$, ... More
A New Approach for Distributed Hypothesis Testing with Extensions to Byzantine-ResilienceMar 14 2019We study a setting where a group of agents, each receiving partially informative private observations, seek to collaboratively learn the true state (among a set of hypotheses) that explains their joint observation profiles over time. To solve this problem, ... More
The beam topology and dynamic emission properties of pulsar B0943+10 -- VI. Discovery of a 'Q'-mode precursor and comparison with pulsar B1822-09Dec 04 2009This paper reports new observations of pulsars B0943+10 and B1822--09 carried out with the Arecibo Observatory (AO) and the Giant Metrewave Radio Telescope (GMRT), respectively. Both stars exhibit two stable emission modes. We report the discovery in ... More