Turbulent flow in graphene (2009)
Gupta, Kumar S., Sen, Siddhartha
We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to...
Deformed Oscillator Algebras and QFT in $\kappa$-Minkowski Spacetime (2009)
Govindarajan, T. R., Gupta, Kumar S., Harikumar, E., Meljanac, S., Meljanac, D.
In this paper we study the deformed statistics and oscillator algebras of quantum fields defined in $\kappa$-Minkowski spacetime. The twisted flip operator obtained from the twist associated with the...
Scalar field dynamics in warped AdS_3 black hole background (2009)
Chakrabarti, Sayan K., Giri, Pulak Ranjan, Gupta, Kumar S.
We study the normal modes of a scalar field in the background of a warped AdS_3 black hole which arises in topologically massive gravity. The explicit forms of the normal mode eigenvalues are found...
Scattering in graphene with impurities : A low energy effective theory (2009)
Gupta, Kumar S., Samsarov, Andjelo, Sen, Siddhartha
We analyze the scattering sector of the Hamiltonians for both gapless and gapped graphene in the presence of a charge impurity using the 2D Dirac equation, which is applicable in the long wavelength...
Gupta, Kumar S., Sen, Siddhartha
We obtain a novel bound state spectrum of the low energy excitations near the Fermi points of graphene in the presence of a charge impurity. The effects of possible short range interactions induced...
Normal mode analysis for scalar fields in BTZ black hole background (2008)
Chakrabarti, Sayan K, Giri, Pulak Ranjan, Gupta, Kumar S.
We analyze the possibility of inequivalent boundary conditions for a scalar field propagating in the BTZ black hole space-time. We find that for certain ranges of the black hole parameters, the...
Bound States in Graphene (2008)
Gupta, Kumar S., Sen, Siddhartha
We present a quantum analysis of the massless excitations in graphene with a charge impurity. When the effective charge exceeds a certain critical value, the spectrum is quantized and is unbounded...
Inequivalent quantization of the rational Calogero model with a Coulomb type interaction (2008)
Basu-Mallick, B., Gupta, Kumar S., Meljanac, S., Samsarov, A.
We consider the inequivalent quantizations of a $N$-body rational Calogero model with a Coulomb type interaction. It is shown that for certain range of the coupling constants, this system admits a...
Twisted Statistics in kappa-Minkowski Spacetime (2008)
Govindarajan, T. R., Gupta, Kumar S., Harikumar, E., Meljanac, S., Meljanac, D.
We consider the issue of statistics for identical particles or fields in kappa-deformed spaces, where the system admits a symmetry group G. We obtain the twisted flip operator compatible with the...
Universal near-horizon conformal structure and black hole entropy (2007)
Chakrabarti, Sayan K., Gupta, Kumar S., Sen, Siddhartha
It is shown that a massless scalar probe reveals a universal near-horizon conformal structure for a wide class of black holes, including the BTZ. The central charge of the corresponding Virasoro...
Interacting Quantum Topologies and the Quantum Hall Effect (2007)
Balachandran, A. P., Gupta, Kumar S., Kurkcuoglu, Seckin
The algebra of observables of planar electrons subject to a constant background magnetic field B is given by A_theta(R^2) x A_theta(R^2) the product of two mutually commuting Moyal algebras. It...
Electron Capture and Scaling Anomaly in Polar Molecules (2007)
Giri, Pulak Ranjan, Gupta, Kumar S., Meljanac, S., Samsarov, A.
We present a new analysis of the electron capture mechanism in polar molecules, based on von Neumann's theory of self-adjoint extensions. Our analysis suggests that it is theoretically possible for...
Noncommutative BTZ Black Hole and Discrete Time (2006)
Dolan, B. P., Gupta, Kumar S., Stern, A.
We search for all Poisson brackets for the BTZ black hole which are consistent with the geometry of the commutative solution and are of lowest order in the embedding coordinates. For arbitrary values...
Black Holes, Holography and Moduli Space Metric (2006)
Gupta, Kumar S., Sen, Siddhartha
String theory can accommodate black holes with the black hole parameters related to string moduli. It is a well known but remarkable feature that the near horizon geometry of a large class of black...
Chakrabarti, Sayan K., Gupta, Kumar S.
We obtain an analytic expression for the highly damped asymptotic quasinormal mode frequencies of the $d\geq 5$-dimensional Schwarzschild black hole modified by the Gauss-Bonnet term, which appears...
Geometric Finiteness and Non-quasinormal Modes of the BTZ Black Hole (2005)
Gupta, Kumar S., Sen, Siddhartha
The BTZ black hole is geometrically finite. This means that its three dimensional hyperbolic structure as encoded in its metric is in 1-1 correspondence with the Teichmuller space of its boundary,...
Waves on Noncommutative Spacetimes (2005)
Balachandran, A. P., Gupta, Kumar S., Kurkcuoglu, S.
Waves on ``commutative'' spacetimes like R^d are elements of the commutative algebra C^0(R^d) of functions on R^d. When C^0(R^d) is deformed to a noncommutative algebra {\cal A}_\theta (R^d) with...
On the Real Spectra of Calogero Model with Complex Coupling (2003)
Ghosh, Pijush K., Gupta, Kumar S.
We study the eigenvalue problem of the rational Calogero model with the coupling of the inverse-square interaction as a complex number. We show that although this model is manifestly non-invariant...
Quantum Inverse Square Interaction (2003)
Hamiltonians with inverse square interaction potential occur in the study of a variety of physical systems and exhibit a rich mathematical structure. In this talk we briefly mention some of the...
Near-Horizon States of Black Holes and Calogero Models (2003)
Basu-Mallick, B, Ghosh, Pijush K., Gupta, Kumar S.
We find self-adjoint extensions of the rational Calogero model in presence of the harmonic interaction. The corresponding eigenfunctions may describe the near-horizon quantum states of certain types...
Hidden Degeneracy in the Brick Wall Model of Black Holes (2003)
Gupta, Kumar S., Sen, Siddhartha
Quantum field theory in the near-horizon region of a black hole predicts the existence of an infinite number of degenerate modes. Such a degeneracy is regulated in the brick wall model by the...
Inequivalent Quantizations of the Rational Calogero Model (2002)
Basu-Mallick, B., Ghosh, Pijush K., Gupta, Kumar S.
We show that the rational Calogero model with suitable boundary condition admits quantum states with non-equispaced energy levels. Such a spectrum generically consists of infinitely many positive...
Novel Quantum States of the Rational Calogero Models Without the Confining Interaction (2002)
Basu-Mallick, B., Ghosh, Pijush K., Gupta, Kumar S.
We show that the N-particle A_{N-1} and B_N rational Calogero models without the harmonic interaction admit a new class of bound and scattering states. These states owe their existence to the...
Near-Horizon Conformal Structure and Entropy of Schwarzschild Black Holes (2002)
Near-horizon conformal structure of a massive Schwarzschild black hole of mass M is analyzed using a scalar field as a simple probe of the background geometry. The near-horizon dynamics is governed...
Black Hole Decay as Geodesic Motion (2002)
Gupta, Kumar S., Sen, Siddhartha
We show that a formalism for analyzing the near-horizon conformal symmetry of Schwarzschild black holes using a scalar field probe is capable of describing black hole decay. The equation governing...
Gupta, Kumar S., Sen, Siddhartha
We study the excitations of a massive Schwarzschild black hole of mass M resulting from the capture of infalling matter described by a massless scalar field. The near-horizon dynamics of this system...
Bound States in One-Dimensional Quantum N-Body Systems with Inverse Square Interaction (2001)
Basu-Mallick, B., Gupta, Kumar S.
We investigate the existence of bound states in a one-dimensional quantum system of $N$ identical particles interacting with each other through an inverse square potential. This system is equivalent...
Near-Horizon Conformal Structure of Black Holes (2001)
Birmingham, Danny, Gupta, Kumar S., Sen, Siddhartha
The near-horizon properties of a black hole are studied within an algebraic framework, using a scalar field as a simple probe to analyze the geometry. The operator H governing the near-horizon...
Quantum Field Theories on Null Surfaces (2000)
We study the behaviour of quantum field theories defined on a surface $S$ as it tends to a null surface $S_n$. In the case of a real, free scalar field theory the above limiting procedure reduces the...
Gupta, Kumar S., Momen, M. Arshad, Schechter, J., Subbaraman, A.
We investigate the heavy baryons which arise as solitonic excitations in a ``heavy meson" chiral Lagrangian which includes the light vector particles. It is found that the effect of the light vectors...