Results for "Sudeshna Boro Saikia"

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Magnetic fields on young, moderately rotating Sun-like stars - I: HD~35296 and HD~29615Feb 20 2015Observations of the magnetic fields of young solar-type stars provide a way to investigate the signatures of their magnetic activity and dynamos. Spectropolarimetry enables the study of these stellar magnetic fields and was thus employed at the T\'{e}lescope ... More
Random Coupling of Chaotic Maps leads to Spatiotemporal SynchronisationMay 04 2002We investigate the spatiotemporal dynamics of a network of coupled chaotic maps, with varying degrees of randomness in coupling connections. While strictly nearest neighbour coupling never allows spatiotemporal synchronization in our system, randomly ... More
New results of the Berliner relativistic quark modelOct 27 1995It is pointed out that the recently measured left-right asymmetries in inclusive pion and lambda hyperon production processes are in very good agreement with the relativistic quark model, proposed some time ago. Further predictions based on this model ... More
On the defining equations of Rees algebra of a height two perfect ideal using the theory of $D$-modulesSep 20 2018Let $k$ be a field of characteristic zero, and $R=k[x_1, \ldots, x_d]$ with $d \geq 3$ be a polynomial ring in $d$ variables. Let $\m=(x_1, \ldots, x_d)$ be the homogeneous maximal ideal of $R$. Let $\mathcal{K}$ be the kernel of the canonical map $\alpha: ... More
Existence of Positive Steady States for Weakly Reversible Mass-Action SystemsOct 12 2017Nov 28 2018We prove the following. For each weakly reversible mass-action system, there exists a positive steady state in each positive stoichiometric class.
Nuclear Corrections in Neutrino Deep Inelastic Scattering and the Extraction of the Strange Quark DistributionJun 18 1998Jun 23 1998Recent measurement of the structure function $F_2^\nu$ in neutrino deep inelastic scattering allows us to compare structure function measured in neutrino and charged lepton scattering for the first time with reasonable precision. The comparison between ... More
Light-Cone Meson-Baryon Fluctuations and Single-Spin AsymmetriesJun 15 1998Feb 09 1999We show that energetically favored meson-baryon fluctuations present in the light-cone wave function of a transversely polarized proton can account for the left-right asymmetries measured in inclusive meson production processes.
Studying stellar spin-down with Zeeman-Doppler magnetogramsMay 04 2017Magnetic activity and rotation are known to be intimately linked for low-mass stars. Understanding rotation evolution over the stellar lifetime is therefore an important goal within stellar astrophysics. In recent years, there has been increased focus ... More
On units generated by Euler systemsOct 08 2009In the context of cyclotomic fields, it is still unknown whether there exist Euler systems other than the ones derived from cyclotomic units. Nevertheless, we first give an exposition on how norm-compatible units are generated by any Euler system, following ... More
Ratchet effect in an underdamped periodic potential and its characterisationAug 28 2016Ratchet effect in a driven underdamped periodic potential system is studied. The presence of a space dependent and periodic friction coefficient, but with a phase difference with the symmetric periodic potential is shown to generate substantial ratchet ... More
Particle dynamics and Stochastic Resonance in Periodic potentialsSep 02 2016We have studied the dynamics of a particle in a periodically driven underdamped periodic potential. Recent studies have reported the occurrence of Stochastic Resonance (SR) in such systems in the high frequency regime, using input energy per period of ... More
Selmer Groups of Elliptic Curves with Complex MultiplicationOct 08 2009This paper contains some results regarding the Iwasawa module structure of Selmer groups of elliptic curves with complex multiplication.
Sharp Lower bound estimates for vector-valued and matrix-valued multipliers in $L^p$Oct 25 2011We generalize the idea of a multiplier in two different ways and generalize a recent result of Geiss, Montomery-Smith and Saksman. First of all, we consider multipliers in the form of a vector acting on a scalar function. Using this technique we compute ... More
Hyers--Ulam stability of derivations and linear functionsJul 02 2013In this paper the following implication is verified for certain basic algebraic curves: if the additive real function $f$ approximately (i.e., with a bounded error) satisfies the derivation rule along the graph of the algebraic curve in consideration, ... More
Permanence of Weakly Reversible Mass-Action Systems with a Single Linkage ClassMar 07 2019We give a new proof of the fact that each weakly reversible mass-action system with a single linkage class is permanent.
Asymptotic Behavior of the $T^3 \times R$ Gowdy SpacetimesSep 16 1992We present new evidence in support of the Penrose's strong cosmic censorship conjecture in the class of Gowdy spacetimes with $T^3$ spatial topology. Solving Einstein's equations perturbatively to all orders we show that asymptotically close to the boundary ... More
On Quadratization of Pseudo-Boolean FunctionsApr 25 2014We survey current term-wise techniques for quadratizing high-degree pseudo-Boolean functions and introduce a new one, which allows multiple splits of terms. We also introduce the first aggregative approach, which splits a collection of terms based on ... More
Distribution of Husimi Zeroes in Polygonal BilliardsApr 26 1999The zeroes of the Husimi function provide a minimal description of individual quantum eigenstates and their distribution is of considerable interest. We provide here a numerical study for pseudo- integrable billiards which suggests that the zeroes tend ... More
Non-universal dependence of spatiotemporal regularity on randomness in coupling connectionsApr 03 2008We investigate the spatiotemporal dynamics of a network of coupled nonlinear oscillators, modeled by sine circle maps, with varying degrees of randomness in coupling connections. We show that the change in the basin of attraction of the spatiotemporal ... More
Tunable Self-assembly of Au-nanoparticles with Near-Perfect MonodispersityMar 29 2006Au nanoparticles with near perfect monodispersity in shape and size self-assemble, very slowly and at room temperature, on polystyrene films for film thickness < 4R_{g}$, R_{g} being unperturbed polymer gyration radius. Nanoparticle shape and size can ... More
On nicely smooth Banach spacesMay 09 1996In this work, we obtain some necessary and some sufficient conditions for a space to be nicely smooth, and show that they are equivalent for separable or Asplund spaces. We obtain a sufficient condition for the Ball Generated Property (BGP), and conclude ... More
The Mixmaster Spacetime, Geroch's Transformation and Constants of MotionSep 09 1993We show that for $U(1)$-symmetric spacetimes on $S^3 \times R$ a constant of motion associated with the well known Geroch transformation, a functional $K[h_{ij},\pi^{ij}]$, quadratic in gravitational momenta, is strictly positive in an open subset of ... More
Bounding Hilbert coefficients of parameter idealsNov 10 2016Let $(R,\mathfrak{m})$ be a Noetherian local ring of dimension $d>0$ and depth R$\geq d-1$. Let $Q$ be a parameter ideal of $R$. In this paper, we derive uniform lower and upper bounds for the Hilbert coefficient $e_i(Q)$ under certain assumptions on ... More
Supercongruences for truncated hypergeometric series and p-adic gamma functionJul 27 2015Sep 03 2015We prove several supercongruences for truncated hypergeometric series and $p$-adic Gamma function. Recently, A. Deines, J. Fuselier, L. Long, H. Swisher and F. Tu posed some open problems on supercongruences based on numeric observations. We prove one ... More
Head Gesture Recognition using Optical Flow based Classification with Reinforcement of GMM based Background SubtractionAug 05 2013This paper describes a technique of real time head gesture recognition system. The method includes Gaussian mixture model (GMM) accompanied by optical flow algorithm which provided us the required information regarding head movement. The proposed model ... More
Periodic Sequences modulo $m$Sep 10 2012Sep 26 2015We give a few remarks on the periodic sequence $a_n=\binom{n}{x}~(mod~m)$ where $x,m,n\in \mathbb{N}$, which is periodic with minimal length of the period being $$\ell(m,x)={\displaystyle\prod^w_{i=1}p^{\lfloor\log_{p_i}x\rfloor+b_i}_i}=m{\displaystyle\prod^w_{i=1}p^{\lfloor\log_{p_i}x\rfloor}_i}$$ ... More
A Study of Kummer's Proof of Fermat's Last Theorem for Regular PrimesJul 11 2013We study Kummer's approach towards proving the Fermat's last Theorem for regular primes. Some basic algebraic prerequisites are also discussed in this report, and also a brief history of the problem is mentioned. We review among other things the Class ... More
On A New Asymptotic Norming PropertyOct 16 1995In this work, we introduce a new Asymptotic Norming Property (ANP) which lies between the strongest and weakest of the existing ones, and obtain isometric characterisations of it. The corresponding w*-ANP turns out to be equivalent on the one hand, to ... More
Balance of interactions determines optimal survival in multi-species communitiesAug 21 2015We consider a multi-species community modelled as a complex network of populations, where the links are given by a random asymmetric matrix J, with fraction 1-C of zero entries, where C reflects the over-all connectivity of the system. The non-zero elements ... More
Robust Emergent Activity in Dynamical NetworksOct 22 2005We study the evolution of a random weighted network with complex nonlinear dynamics at each node, whose activity may cease as a result of interactions with other nodes. Starting from a knowledge of the micro-level behaviour at each node, we develop a ... More
Single spin asymmetries in inclusive high energy hadron-hadron collision processesJan 31 2000It has been realized for quite a long time that single-spin experiments, in which one of the colliding objects is transversely polarized, can be helpful in studying the properties of strong interaction in general and in testing Quantum Chromodynamics ... More
Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisionsJan 31 2000We discuss Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron scattering at high energies. We show that the physical picture proposed in a recent Letter is consistent with the experimental observation that $\Lambda$ ... More
Dynamic Transitions in Small World Networks: Approach to EquilibriumJul 07 2005We study the transition to phase synchronization in a model for the spread of infection defined on a small world network. It was shown (Phys. Rev. Lett. {\bf 86} (2001) 2909) that the transition occurs at a finite degree of disorder $p$, unlike equilibrium ... More
Suppression of chaos through coupling to an external chaotic systemJul 02 2016We explore the behaviour of an ensemble of chaotic oscillators coupled only to an external chaotic system, whose intrinsic dynamics may be similar or dissimilar to the group. Counter-intuitively, we find that a dissimilar external system manages to suppress ... More
Spin content of Lambda and its longitudinal polarization in $e^+e^-$ annihilation at high energiesMar 03 1998Longitudinal polarization of Lambda produced in $e^+e^-$ annihilation at LEP energies is calculated in a picture for the spin content of Lambda which is consistent with the polarized deep inelastic lepton-nucleon scattering data and SU(3) flavor symmetry ... More
Numerical simulations of particle sedimentation using the immersed boundary methodApr 02 2013Nov 07 2013We study the settling of solid particles within a viscous incompressible fluid contained in a two-dimensional channel, where the mass density of the particles is slightly greater than that of the fluid. The fluid-structure interaction problem is simulated ... More
Pion Exchange and the H1 Forward Spectrometer DataDec 07 1998Mar 02 1999We point out that the $\Delta\pi$ component of the nucleon wave function is vital to the interpretation of the recent H1 data for leading baryon production. While the $n/p$ ratio is equal to two with the $N\pi$ component alone, the inclusion of the $\Delta\pi$ ... More
An Interesting Number Theoretic ProblemAug 13 2012In this short note we prove a result that is an extension of an old Olympiad problem and is a very simple variant of the question of finding an approximation for $k$, where it is a nonzero constant and it satisfies the equation $a^k+b^k=c$, where $a,b,c$ ... More
Summation identities and transformations for hypergeometric seriesSep 22 2016We find summation identities and transformations for the McCarthy's $p$-adic hypergeometric series by evaluating certain Gauss sums which appear while counting points on the family $$Z_{\lambda}: x_1^d+x_2^d=d\lambda x_1x_2^{d-1}$$ over a finite field ... More
Landen transformations and the integration of rational functionsJul 26 2007We present a rational version of the classical Landen transformation for elliptic integrals. This is employed to obtain explicit closed-form expressions for a large class of integrals of even rational functions and to develop an algorithm for the numerical ... More
Graded components of Local cohomology modules IIAug 04 2017Let $A$ be a commutative Noetherian ring containing a field $K$ of characteristic zero and let $R= A[X_1, \ldots, X_m]$. Consider $R$ as standard graded with $\deg A=0$ and $\deg X_i=1$ for all $i$. We present a few results about the behavior of the graded ... More
Protocols for characterizing quantum transport through nano-structuresMay 17 2012Sep 05 2012In this work, we have analyzed the exact closed-form solutions for transport quantities through a mesoscopic region which may be characterized by a polynomial functional of resonant transmission functions. These are then utilized to develop considerably ... More
Graded components of local cohomology modules of invariant ringsSep 28 2017Let $A$ be a regular domain containing a field $K$ of characteristic zero, $G$ be a finite subgroup of the group of automorphisms of $A$ and $B=A^G$ be the ring of invariants of $G$. Let $S= A[X_1,\ldots, X_m]$ and $R= B[X_1, \ldots, X_m]$ be standard ... More
Linear Hahn Banach Type Extension Operators in Banach Algebras of OperatorsOct 07 2017The notion of linear Hahn-Banach extension operator was first studied in detail by Heinrich and Mankiewicz (1982). Previously, J. Lindenstrauss (1966) studied similar versions of this notion in the context of non separable reflexive Banach spaces. Subsequently, ... More
Cranks in Ramanujan's Lost NotebookJan 22 2014May 01 2014We give a brief review of the work of Ramanujan on cranks that is found in the Lost Notebook. Recent work by Bruce Berndt and his coauthors have brought to light many interesting results of Ramanujan on cranks, which we highlight in this article.
Supercongruences for truncated hypergeometric series and p-adic gamma functionJul 27 2015Jul 10 2018We prove three more general supercongruences between truncated hypergeometric series and $p$-adic Gamma function from which some known supercongruences follow. A supercongruence conjectured by Rodriguez-Villegas and proved by E. Mortenson using the theory ... More
A study of the crank function in Ramanujan's Lost NotebookMay 26 2014May 13 2015In this note, we shall give a brief survey of the results that are found in Ramanujan's Lost Notebook related to cranks. Recent work by B. C. Berndt, H. H. Chan, S. H. Chan and W. -C. Liaw have shown conclusively that cranks was the last mathematical ... More
Enumeration of Domino Tilings of an Aztec Rectangle with boundary defectsMay 30 2016Helfgott and Gessel gave the number of domino tilings of an Aztec Rectangle with defects of size one on the boundary of one side. In this paper we extend this to the case of domino tilings of an Aztec Rectangle with defects on all boundary sides.
The Pythagoras' TheoremSep 30 2013Oct 22 2013We give a brief historical overview of the famous Pythagoras' theorem and Pythagoras. We present a simple proof of the result and dicsuss some extensions. We follow \cite{thales}, \cite{wiki} and \cite{wiki2} for the historical comments and sources.
Polarization of radio cores as a test of the unified schemesNov 20 1998In the unified schemes for extragalactic radio sources, the quasars and BL Lac objects are intrinsically similar to the Fanaroff-Riley class II and I radio galaxies respectively, but appear to be different because they are viewed at different angles to ... More
Some Congruences of a Restricted Bipartition FunctionMar 30 2016Let $c_N(n)$ denotes the number of bipartitions $(\lambda, \mu)$ of a positive integer $n$ subject to the restriction that each part of $\mu$ is divisible by $N$. In this paper, we prove some congruence properties of the function $c_N(n)$ for $N=7$, 11, ... More
Explicit Solutions for $u^{2}-pv^{2}=\pm 2$ and a Conjecture of MordellOct 14 2018We obtain an explicit solution of the Pell's equation ${{u^{2}-pv^{2}=\pm 2}}$ in terms of the convergents of the continued fraction of the prime $p$. Then we show that Mordell's conjecture concerning the fundamental unit of $\mathbb{Q}(\sqrt{p})$ holds ... More
Hyperon polarization and single spin left-right asymmetry in inclusive production processes at high energiesAug 29 1997Nov 25 1997It is shown that the polarization of hyperons observed in high energy collisions using unpolarized hadron beams and unpolarized nucleon or nuclear targets is closely related to the left-right asymmetries observed in single spin inclusive hadron production ... More
A dichotomy property for the graphs of monomialsOct 30 2014Jul 31 2015We prove that the graph of a discontinuous $n$-monomial function $f:\mathbb{R}\to\mathbb{R}$ is either connected or totally disconnected. Furthermore, the discontinuous monomial functions with connected graph are characterized as those satisfying a certain ... More
Parton Distributions for the Octet and Decuplet BaryonsFeb 17 1999We calculate the parton distributions for both polarized and unpolarized octet and decuplet baryons, using the MIT bag, dressed by mesons. We show that the hyperfine interaction responsible for the $\Delta - N$ and $\Sigma^0 - \Lambda$ splittings leads ... More
Hyperon production mechanisms and single-spin asymmetry in high energy hadron-hadron collisionsOct 17 1995It is shown that the existence of left-right asymmetry in single-spin inclusive Lambda production, together with the characteristic features of the data, should be considered as another clear signature for the existence of orbiting valence quarks in polarized ... More
Deterministic inhomogeneous inertia ratchetsApr 05 2010We study the deterministic dynamics of a periodically driven particle in the underdamped case in a spatially symmetric periodic potential. The system is subjected to a space-dependent friction coefficient, which is similarly periodic as the potential ... More
A radio study of the superwind galaxy NGC1482Nov 23 2004We present multifrequency radio continuum as well as HI observations of the superwind galaxy NGC1482, with both the GMRT and the VLA. This galaxy has a remarkable hourglass-shaped optical emission line outflow as well as bi-polar soft X-ray bubbles on ... More
Dispersionless motion in a driven periodic potentialAug 07 2009Recently, dispersionless (coherent) motion of (noninteracting) massive Brownian particles, at intermediate time scales, was reported in a sinusoidal potential with a constant tilt. The coherent motion persists for a finite length of time before the motion ... More
HI absorption towards low luminosity radio-loud AGNs of different accretion modes and WISE coloursJul 04 2016Oct 18 2016H{\sc i} absorption studies of active galaxies enable us to probe their circumnuclear regions and the general interstellar medium, and study the supply of gas which may trigger the nuclear activity. In this paper, we investigate the detection rate of ... More
Quantum critical Mott transitions in a bilayer Kondo insulator-metal model systemNov 20 2015Sep 09 2016A bilayer system comprising a Kondo insulator coupled to a simple metal (KI-M) is considered. Employing the framework of dynamical mean field theory, the model system is shown to exhibit a surface of quantum critical points (QCPs), that separates a Kondo ... More
How Crucial is Small World Connectivity for Dynamics?May 21 2004We study the dynamical behaviour of the collective field of chaotic systems on small world lattices. Coupled neuronal systems as well as coupled logistic maps are investigated. We observe that significant changes in dynamical properties occur only at ... More
The bend elastic constant in a mixture of (4,4')-n-octyl-cyanobiphenyl and biphenylMar 12 2001The effect of a rigid, non-polar and nonmesogenic solute biphenyl ((C_{6}H_{5}-C_{6}H_{5})) on the divergence of the bend elastic constant K_{33} of (4,4^{\prime}) -n-octyl-cyanobiphenyl (8CB) near the smecticA-nematic transition is reported. The exponent ... More
Singularity free analysis of a self-similar model of proton structure function at small \textit{x}Sep 01 2014In this paper we make re-analysis of a self-similarity based model of the proton structure function at small \textit{x} pursued in recent years. The additional assumption is that it should be singularity free in the entire kinematic range $0<\textit{x}<1$. ... More
Unification scheme and the distribution of neutral gas in compact radio sourcesMay 17 2006We examine the consistency of HI properties with the unification scheme for radio galaxies and quasars, and any correlation with the symmetry parameters for a sample of CSS and GPS sources. In our sample, 15 out of 23 galaxies exhibit 21-cm absorption ... More
Polarization asymmetry in CSS sources: evidence of AGN fuel?Apr 29 2003The compact steep spectrum and gigahertz peaked spectrum sources are widely believed to be young radio sources, with ages <10^6 yr. If the activity in the nucleus is fuelled by the supply of gas, one might find evidence of this gas by studying the structural ... More
Recurrent Activity in Active Galactic NucleiFeb 09 2010There has been a growing body of evidence to suggest that AGN activity, which is powered by mass accretion on to a supermasive black hole, could be episodic, although the range of time scales involved needs to be explored further. The structure and spectra ... More
Double-double radio galaxies from the FIRST surveyAug 09 2012The radio structures and optical identifications of a sample of 242 sources classified as double-double radio sources by Proctor (2011) from a morphological study of sources in the FIRST (Faint Images of the Radio Sky at Twenty centimeters) survey (2003 ... More
An HI study of three long-tailed irregular galaxies in the cluster Abell1367Jun 21 2007We present the results on the distribution and kinematics of H$\sc{i}$ gas with higher sensitivity and in one case of higher spectral resolution as well than reported earlier, of three irregular galaxies CGCG 097073, 097079 and 097087 (UGC 06697) in the ... More
On the divisibility of class numbers of quadratic fields and the solvability of Diophantine equationsOct 26 2017In this paper we provide criteria for the insolvability of the Diophantine equation $x^2+D=y^n$. This result is then used to determine the class number of the quadratic field $\mathbb{Q}(\sqrt{-D})$. We also determine some criteria for the divisibility ... More
A Simple Number Theoretic ResultJul 28 2012We derive an interesting congruence relation motivated by an Indian Olympiad problem. We give three different proofs of the theorem and mention a few interesting related results.
Effect of asynchronicity on the universal behaviour of coupled map latticesMay 10 2002We investigate the spatiotemporal dynamics of coupled circle map lattices, evolving under synchronous (parallel) updating on one hand and asynchronous (random) updating rules on the other. Synchronous evolution of extended spatiotemporal systems, such ... More
Evidence for directed percolation universality at the onset of spatiotemporal intermittency in coupled circle mapsOct 16 2002We consider a lattice of coupled circle maps, a model arising naturally in descriptions of solid state phenomena such as Josephson junction arrays. We find that the onset of spatiotemporal intermittency (STI) in this system is analogous to directed percolation ... More
On some families of integrals solvable in terms of polygamma and negapolygamma functionsMay 09 2003Beginning with Hermite's integral representation of the Hurwitz zeta function, we derive explicit expressions in terms of elementary, polygamma, and negapolygamma functions for several families of integrals of the type $\int_0^\infty f(t)K(q,t)dt$ with ... More
Transverse Momentum Dependent Parton Distributions with self-similarity at small $x$ and models of proton structure functionMay 04 2016In this paper we make re-analysis of a self-similarity based model of the proton structure function at small $x$ pursued in recent years. The additional assumption is that it should be singularity free in the entire kinematic range $0\leq \textit{x}\leq ... More
Some results about Linear Recurrence Relation HomomorphismsMay 23 2013Sep 23 2014In this paper we propose a definition of a recurrence relation homomorphism and illustrate our definition with a few examples. We then define the period of a k-th order of linear recurrence relation and deduce certain preliminary results associated with ... More
The $L^p-$Operator Norm of a Quadratic Perturbation of the Real Part of the Ahlfors--Beurling OperatorSep 19 2011Sep 22 2011We will explain how to compute the exact $L^p$ operator norm of a "quadratic perturbation" of the real part of the Ahlfors--Beurling operator. For the lower bound estimate we use a new approach of constructing a sequence of laminates (probability measures ... More
Equistarable bipartite graphsFeb 23 2015Recently, Milani\v{c} and Trotignon introduced the class of equistarable graphs as graphs without isolated vertices admitting positive weights on the edges such that a subset of edges is of total weight $1$ if and only if it forms a maximal star. Based ... More
On global stability of the Lotka reactions with generalized mass-action kineticsNov 17 2016Chemical reaction networks with generalized mass-action kinetics lead to power-law dynamical systems. As a simple example, we consider the Lotka reactions with two chemical species and arbitrary power-law kinetics. We study existence, uniqueness, and ... More
Characterizing and decomposing classes of threshold, split, and bipartite graphs via 1-Sperner hypergraphsMay 09 2018May 29 2018A hypergraph is said to be $1$-Sperner if for every two hyperedges the smallest of their two set differences is of size one. We present several applications of $1$-Sperner hypergraphs and their structure to graphs. In particular, we consider the classical ... More
1-Sperner hypergraphsOct 08 2015We introduce a new class of hypergraphs, the class of $1$-Sperner hypergraphs. A hypergraph ${\cal H}$ is said to be $1$-Sperner if every two distinct hyperedges $e,f$ of ${\cal H}$ satisfy $\min\{|e\setminus f|,|f\setminus e|\} = 1$. We prove a decomposition ... More
Perturbation of Burkholder's martingale transform and Monge--Ampère equationFeb 18 2011Let $\{d_k\}_{k \geq 0}$ be a complex martingale difference in $L^p[0,1],$ where $1<p<\infty,$ and $\{\e_k\}_{k \geq 0}$ a sequence in $\{\pm 1\}.$ We obtain the following generalization of Burkholder's famous result. If $\tau \in [-\frac 12, \frac 12]$ ... More
On CIS CirculantsFeb 14 2013A circulant is a Cayley graph over a cyclic group. A well-covered graph is a graph in which all maximal stable sets are of the same size, or in other words, they are all maximum. A CIS graph is a graph in which every maximal stable set and every maximal ... More
Under what kind of parametric fluctuations is spatiotemporal regularity the most robust?Jul 05 2008It was observed that the spatiotemporal chaos in lattices of coupled chaotic maps was suppressed to a spatiotemporal fixed point when some fraction of the regular coupling connections were replaced by random links. Here we investigate the effects of different ... More
Enhancement of spatiotemporal regularity in an optimal window of random couplingJul 05 2008We investigate the spatiotemporal dynamics of a lattice of coupled chaotic maps whose coupling connections are dynamically rewired to random sites with probability p, namely at any instance of time, with probability p a regular link is switched to a random ... More
Electrical and magnetic transport study on strain driven ferromagnetic insulating thin film of low doped manganiteDec 31 2012In this paper we have created a strain driven single crystal like ferromagnetic insulating (FMI) state in a PLD grown thin film of low doped LCMO(X = 0.15)on NGO(100) substrate and make a thorough study of strain effects on the electric and magnetic transport ... More
Spatiotemporal Regularity in Networks with Stochastically Varying LinksApr 11 2014In this work we investigate time varying networks with complex dynamics at the nodes. We consider two scenarios of network change in an interval of time: first, we have the case where each link can change with probability pt, i.e. the network changes ... More
Collimation of extragalactic radio jets in compact steep spectrum and larger sourcesApr 19 1999Oct 05 1999We study the collimation of radio jets in the high-luminosity Fanaroff-Riley class II sources by examining the dependence of the sizes of hotspots and knots in the radio jets on the overall size of the objects for a sample of compact steep-spectrum or ... More
Binomial Symbols and Prime ModuliSep 07 2012We try to improve a problem asked in an Indian Math Olympiad. We give a brief overview of the work done in Saikia and Vogrinc (2011) and Saikia and Vogrinc where the authors have found a periodic sequence and the length of its period, all inspired from ... More
Ratchet effect in inhomogeneous inertial systems: II. The square-wave drive caseJul 28 2008The underdamped Langevin equation of motion of a particle, in a symmetric periodic potential and subjected to a symmetric periodic forcing with mean zero over a period, with nonuniform friction, is solved numerically. The particle is shown to acquire ... More
Radio bubbles in the composite AGN-starburst galaxy NGC6764Jul 20 2006We present multi-frequency radio continuum as well as HI observations of the composite galaxy NGC6764, which has a young, circumnuclear starburst and also harbours an active galactic nucleus (AGN). These observations have been made at a number of frequencies ... More
Some Properties of Fibonacci Numbers, Generalized Fibonacci Numbers and Generalized Fibonacci Polynomial SequencesSep 19 2012Jun 10 2015In this paper we study the Fibonacci numbers and derive some interesting properties and recurrence relations. We prove some charecterizations for $F_p$, where $p$ is a prime of a certain type. We also define period of a Fibonacci sequence modulo an integer, ... More
A new proof of Lucas' TheoremJan 16 2013We give a new proof of Lucas' Theorem in elementary number theory.
Analytical computation of process noise matrix in Kalman filter for fitting curved tracks in magnetic field within dense, thick scatterersDec 14 2015Jul 20 2016In the context of track fitting problems by a Kalman filter, the appropriate functional forms of the elements of the random process noise matrix are derived for tracking through thick layers of dense materials and magnetic field. This work complements ... More
Noise Enhanced Activity in a Complex NetworkDec 23 2013We consider the influence of local noise on a generalized network of populations having positive and negative feedbacks. The population dynamics at the nodes is nonlinear, typically chaotic, and allows cessation of activity if the population falls below ... More
Effect of a rigid nonpolar solute on the splay, bend elastic constants and on rotational viscosity coefficient of 4-4^\prime -n-octyl-cyanobiphenylNov 27 2000Jan 22 2001The effect of a rigid nonpolar non-mesogenic solute, ``biphenyl'' which is (C_{6}H_{5}-C_{6}H_{5}), on the splay and bend elastic constants and on the rotational viscosity coefficient of (4,4^{\prime})-n-octyl-cyano biphenyl (8CB) is reported. The experiments ... More
FPT algorithms for embedding into low complexity graphic metricsJan 10 2018Jun 26 2018The Metric Embedding problem takes as input two metric spaces $(X,D_X)$ and $(Y,D_Y)$, and a positive integer $d$. The objective is to determine whether there is an embedding $F:X \rightarrow Y$ such that $d_{F} \leq d$, where $d_{F}$ denotes the distortion ... More
Multivariate Complexity Analysis of Geometric {\sc Red Blue Set Cover}Nov 24 2015Nov 25 2015We investigate the parameterized complexity of GENERALIZED RED BLUE SET COVER (Gen-RBSC), a generalization of the classic SET COVER problem and the more recently studied RED BLUE SET COVER problem. Given a universe $U$ containing $b$ blue elements and ... More
Emergence of Persistent Infection due to HeterogeneityMay 27 2016We explore the emergence of persistent infection in a patch of population, where the disease progression of the individuals is given by the SIRS model and an individual becomes infected on contact with another infected individual. We investigate the persistence ... More
Laminates Meet Burkholder FunctionsSep 22 2011Dec 07 2011We will explain how to compute the exact $L^p$ operator norm of a "quadratic perturbation" of the real part of the Ahlfors--Beurling operator. For the lower bound estimate we use a new approach of constructing a sequence of laminates (probability measures ... More