Quantum entanglement in a non-commutative system (2008)
Adhikari, S., Chakraborty, B., Majumdar, A. S., Vaidya, S.
We explore the effect of two-dimensional position-space non-commutativity on the bipartite entanglement of continuous variable systems. We first extend the standard symplectic framework for studying...
A statistical mechanics framework for static granular matter (2008)
The physical properties of granular materials have been extensively studied in recent years. So far, however, there exists no theoretical framework which can explain the observations in a unified...
Phonon renormalisation in doped bilayer graphene (2008)
Das, A., Chakraborty, B., Piscanec, S., Pisana, S., Sood, A. K., Ferrari, A. C.
We report phonon renormalisation in bilayer graphene as a function of doping. The Raman G peak stiffens and sharpens for both electron and hole doping, as a result of the non-adiabatic Kohn anomaly...
Wigner Oscillators, Twisted Hopf Algebras and Second Quantization (2008)
Castro, P. G., Chakraborty, B., Toppan, F.
By correctly identifying the role of central extension in the centrally extended Heisenberg algebra h, we show that it is indeed possible to construct a Hopf algebraic structure on the corresponding...
Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor (2008)
Das, A, Pisana, S, Chakraborty, B, Piscanec, S, Saha, SK, Waghmare, UV, ...
The recent discovery of graphene has led to many advances in two-dimensional physics and devices. The graphene devices fabricated so far have relied on $SiO_2$ back gating. Electrochemical top gating...
Mukhopadhyay, R., Rajesh, M., De, Suritha, Chakraborty, B., Jauhari, P.
Integrated geological and geophysical explorations over the last two decades along the central western continental margin of India reveal, from east to west, a terrace-like flat shelf, an advancing...
Seafloor characterization using time-dependent acoustic backscatter: Study at Arabian Sea (2008)
This paper presents application of `inversion modeling` technique to echo shape data acquired shallow water regions off Goa. The estimated sediment and seafloor roughness parameter for two different...
Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor (2008)
Das, A, Pisana, S, Chakraborty, B, Piscanec, S, Saha, SK, Waghmare, UV, ...
The recent discovery of graphene has led to many advances in two-dimensional physics and devices. The graphene devices fabricated so far have relied on $SiO_2$ back gating. Electrochemical top gating...
Shapes of Semiflexible Polymers in Confined Spaces (2007)
We investigate the conformations of a semiflexible polymer confined to a square box. Results of Monte Carlo simulations show the existence of a shape transition when the persistence length of the...
Spectrum of the non-commutative spherical well (2007)
Scholtz, FG, Chakraborty, B, Govaerts, J, Vaidya, S
We give precise meaning to piecewise constant potentials in non-commutative quantum mechanics. In particular, we discuss the infinite and finite non-commutative spherical wells in two dimensions....
Spectrum of the non-commutative spherical well (2007)
Scholtz, F. G., Chakraborty, B., Govaerts, J., Vaidya, S.
We give precise meaning to piecewise constant potentials in non-commutative quantum mechanics. In particular we discuss the infinite and finite non-commutative spherical well in two dimensions. Using...
Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering (2007)
Das, A., Pisana, S., Piscanec, S., Chakraborty, B., Saha, S. K., Waghmare, U. V., ...
We demonstrate electrochemical top gating of graphene by using a solid polymer electrolyte. This allows to reach much higher electron and hole doping than standard back gating. In-situ Raman...
Roy, S.K., Tomkins, A.M., Akramuzzaman, S.M., Chakraborty, B., Ara, G., Biswas, R., ...
This study was conducted to explore whether supplementation of zinc to children during persistent diarrhoea has any subsequent effect on morbidity and growth. A prospective follow-up study was...
Roy, S.K., Khan, W.A., Ara, G, Chakraborty, B., Islam, S., ...
To determine the risk factors for death of severely-malnourished Bangladeshi children with shigellosis, a case-control study was conducted at the Clinical Research and Service Centre of ICDDR,B:...
On the role of twisted statistics in the noncommutative degenerate electron gas (2007)
Khan, S., Chakraborty, B., Scholtz, F. G.
We consider the problem of a degenerate electron gas in the background of a uniformly distributed positive charge, ensuring overall neutrality of the system, in the presence of non-commutativity. In...
Roy, S.K., Tomkins, A.M., Akramuzzaman, S.M., Chakraborty, B., Ara, G., Biswas, R., ...
This study was conducted to explore whether supplementation of zinc to children during persistent diarrhoea has any subsequent effect on morbidity and growth. A prospective follow-up study was...
Dynamics of Microtubule Growth and Catastrophe (2007)
Antal, T., Krapivsky, P. L., Redner, S., Mailman, M., Chakraborty, B.
We investigate a simple model of microtubule dynamics in which a microtubule evolves by: (i) attachment of guanosine triphosphate (GTP) to its end at rate lambda, (ii) GTP converting irreversibly to...
Beyer, A., Chakraborty, B., Schenke, H.W.
In this study multibeam angular backscatter data acquired in the eastern slope of the Porcupine Seabight are analysed. Processing of the angular backscatter data using the ‘NRGCOR’ software was...
Acoustic characterization of seafloor habitats on the western continental shelf of India (2007)
Chakraborty, B., Mahale, V., Navelkar, G.S., Rao, B.R., Desai, R.G.P., Ingole, B., ...
This is a study of the interaction effects of the dual frequency (210 and 33 kHz) backscatter signal with seafloor sediment and benthic biota along a transect in water 27–83 m deep offshore of the...
Quantitative characteristics of the Indian Ocean seafloor relief using fractal dimension (2007)
Chakraborty, B., Mahale, V., Shashikumar, K., Srinivas, K.
In this paper spectral technique has been applied for seafioor topographic data analyses from three seafioor provinces of the Indian Ocean. Study sites include West of the Andaman Island (WAT),...
Spectrum of the non-commutative spherical well (2007)
Scholtz, FG, Chakraborty, B, Govaerts, J, Vaidya, S
We give precise meaning to piecewise constant potentials in non-commutative quantum mechanics. In particular, we discuss the infinite and finite non-commutative spherical wells in two dimensions....
S. K. Roy, W. A. Khan, G. Ara, B. Chakraborty, S. Islam, ...
To determine the risk factors for death of severely-malnourished Bangladeshi children with shigellosis, a case-control study was conducted at the Clinical Research and Service Centre of ICDDR,B:...
Chakraborty, B., Mahale, V., Navelkar, G.S., Desai, R.G.P.
In this paper seafloor classifications system based on artificial neural network (ANN) has been designed. The ANN architecture employed here is a combination of Self Organizing Feature Map (SOFM) and...
Interactions and non-commutativity in quantum Hall systems (2005)
Scholtz, F G, Chakraborty, B, Gangopadhyay, S, Govaerts, J
We discuss the role that interactions play in the non-commutative structure that arises when the relative coordinates of two interacting particles are projected onto the lowest Landau level. It is...
Roy, S.K., Khan, W.A., Ara, G., Chakraborty, B., Islam, S., ...
Duel frequency echo data acquisition system for sea-floor classification (2005)
Navelkar, G.S., Desai, R.G.P., Chakraborty, B.
An echo data acquisition system is designed to digitize echo signal from a single beam shipboard echo-sounder for use in sea-floor classification studies using a 12 bit analog to digital (A/D) card...
Chakraborty, B., Navelkar, G.S., Desai, R.G.P., Janakiraman, G., Mahale, V., Fernandez, W., ...
Seafloor classifications and characterization using acoustic backscatter data from the central western continental shelf of India is presented in this work. Single beam sea-floor echo data using two...
Seafloor backscatter signal simulation and classification (2005)
Mahale, V., El Dine, W.G., Chakraborty, B.
In this paper, simulation study is initiated to observe the interaction effect of the sound signal with different seafloors types and its classification. Simulation of the echo envelope signal is...
Chakraborty, B., Mahale, V., DeSouza, C., Das, P.
This letter presents seafloor classification study results of a hybrid artificial neural network architecture known as learning vector quantization. Single beam echo-sounding backscatter waveform...
Chakraborty, B., Kodagali, V.N.
Application of quantitative angular backscatter modelling to manganese nodule-bearing areas of the Central Indian Ocean Basin (CIOB) has been initiated at NIO during the year 1998. Studies were aimed...
Field evaluation of navigational sensors using DGPS/GPS for a small AUV (2003)
Mehra, P., Desai, R.G.P., Sukerkar, A., Desa, E.S., Navelkar, G.S., ...
This paper presents the preliminary results of a field experiment for low-cost strap down IMU/GPS combination for the estimation of 2-D components of vehicle position (Trajectory). In present...
Chakraborty, B., Kodagali, V.N., Baracho, J.
The presently studied numerical model, e.g., composite roughness, is successful for the purpose of sea-floor classification employing processed multibeam angular backscatter data from...
For quantitative seafloor roughness characterization and classification using multi-beam processed backscatter data, a good correlation is indicated among the power law parameters (composite...
Preliminary results of a recent cruise to the Northern Central Indian Ridge (2002)
Drolia R.K., Iyer, S.D., Chakraborty, B., Kodagali, V.N., Mukhopadhyay, R., Nanyasi, S.K., ...
Chakraborty, B., Schenke, H.W., Kodagali, V.N., Hagen, R.
Utilizing a hull-mounted, multinarrow beam echosounder onboard RV Polarstern, variation of acoustic backscatter with incidence angles at two different sites in the Southern Oceans (Agulhas Plateau...
A neural network based seafloor classification using acoustic backscatter (2002)
This paper presents a study results of the Artificial Neural Network (ANN) architectures [Self-Organizing Map (SOM) and Multi-Layer Perceptron (MLP)] using single beam echosounding data. The single...
$CP^{1}$ model with Hopf interaction: the quantum theory (2000)
Chakraborty, B., Ghosh, Subir, Malik, R. P.
The $CP^1$ model with Hopf interaction is quantised following the Batalin-Tyutin (BT) prescription. In this scheme, extra BT fields are introduced which allow for the existence of only commuting...
Solitons in a gauged Landau-Lifshitz model (1999)
Chakraborty, B., Majumdar, A. S.
We study the gauged Landau-Lifshitz model in which a suitably chosen triplet of background scalar fields is included. It is shown that the model admits solitonic configurations.
Hamiltonian Analysis of Gauged $CP^1$ Model, the Hopf term, and fractional spin (1998)
Chakraborty, B., Majumdar, A. S.
Recently it was shown by Cho and Kimm that the gauged $CP^1$ model, obtained by gauging the global $SU(2)$ group and adding a corresponding Chern-Simons term, has got its own soliton. These solitons...
Monte Carlo Study of Short-Range Order and Displacement Effects in Disordered CuAu (1998)
Malis, O., Ludwig, K. F., Olmsted, D. L., Chakraborty, B.
The correlation between local chemical environment and atomic displacements in disordered CuAu alloy has been studied using Monte Carlo simulations based on the effective medium theory (EMT) of...
Mode Analysis and Duality Symmetry in Different Dimensions (1998)
The problem of duality symmetry in free field models is examined in details by performing a mode expansion of these fields which provides a mapping with the purely quantum mechanical example of a...
Hamiltonian analysis of gauged CP^1 model, with or without Hopf term, and fractional spin (1997)
Recently it has been shown by Cho and Kimm that the gauged $CP^1$ model, obtained by gauging the global SU(2) group of $CP^1$ model and adding a corresponding Chern-Simons term, has got its own...
Chakraborty, B., Majumdar, A. S.
We couple the Hopf term to the relativistic $CP^1$ model and carry out the Hamiltonian analysis at the classical level. The symplectic structure of the model given by the set of Dirac Brackets among...
Hamiltonian Formulation of Quantum Hall Skyrmions with Hopf Term (1997)
Chakraborty, B., Govindarajan, T. R.
We study the nonrelativistic nonlinear sigma model with Hopf term in this paper. This is an important issue beacuse of its relation to the currently interesting studies in skyrmions in quantum Hall...
Studes and high resolution array processing algorithms for multibeam bathymetric applications (1995)
Some aspects of ion-acoustic whistlers in the ionosphere in the presence of negative ions (1989)
A. K. Sur, G. C. Das, B. Chakraborty, S. N. Paul, L. Debnath
A study is made of the propagation of ion-acoustic whistlers in the atmosphere including the effects of negative ions. The dispersion relation, phase and group velocities of whistlers are discussed....
S. N. Paul, B. Chakraborty, L. Debnath
A study is made of nonlinear waves in plasmas using the formalism of a special Lorentz transformation for a space-independent frame, S′. This special transformation is used to transform...