S. M. Roy

Bell Inequalities in Phase Space and their Violation in Quantum Mechanics (2005)

We study the problem of constructing a probability density in 2N-dimensional phase space which reproduces a given collection of $n$ joint probability distributions as marginals. Only distributions...

Auberson, G., Mahoux, G., Roy, S. M., Singh, Virendra

We derive ``Bell inequalities\'\' in four dimensional phase space and prove the following ``three marginal theorem\'\' for phase space densities $\\rho(\\overrightarrow{q},\\overrightarrow{p})$, thus...

Unitarity bounds on elastic absorptive parts in terms of the diffraction peak width (2005)

Auberson, G, Roy, S M

McDowell and Martin (1964) derived a lower bound on the forward logarithmic slope b of the absorptive contribution to the elastic differential cross-section d sigma /sup A//dt of two spinless...

Marginal distributions in $(\bf 2N)$-dimensional phase space and the quantum $(\bf N+1)$ marginal theorem (2004)

N-Partite Separability Inequalities Exponentially Stronger Than Local Reality inequalities (2004)

We study the problem of constructing a probability density in 2N-dimensional phase space which reproduces a given collection of $n$ joint probability distributions as marginals. Only distributions...

Upper bounds on the fine structure constant and on nucleon magnetic moments in terms of Compton scattering cross-section (2004)

For an N-partite quantum system we show that separability implies inequalities on Bell correlations which are stronger than the local reality inequalities by a factor 2^{(N-1)/2}.

Roy, S M, Vengurlekar, A S

A scaling property of shrinking diffraction peaks (2004)

Auberson, G, Roy, S M

Marginal distributions in $(\\bf 2N)$-dimensional phase space and the quantum $(\\bf N+1)$ marginal theorem (2004)

Marginal distributions in $(\\bf 2N)$-dimensional phase space and the quantum $(\\bf N+1)$ marginal theorem (2004)

We study the problem of constructing a probability density in 2N-dimensional phase space which reproduces a given collection of $n$ joint probability distributions as marginals. Only distributions...

Bell Inequalities in Phase Space and their Violation in Quantum Mechanics (2002)

We study the problem of constructing a probability density in 2N-dimensional phase space which reproduces a given collection of $n$ joint probability distributions as marginals. Only distributions...

Auberson, G., Mahoux, G., Roy, S. M., Singh, Virendra

We derive ``Bell inequalities'' in four dimensional phase space and prove the following ``three marginal theorem'' for phase space densities $\rho(\overrightarrow{q},\overrightarrow{p})$, thus...

Bell Inequalities in Phase Space and their Violation in Quantum Mechanics (2002)

Auberson, G., Mahoux, G., Roy, S. M., Singh, Virendra

We derive ``Bell inequalities\'\' in four dimensional phase space and prove the following ``three marginal theorem\'\' for phase space densities $\\rho(\\overrightarrow{q},\\overrightarrow{p})$, thus...

Bell Inequalities in Phase Space and their Violation in Quantum Mechanics (2002)

Auberson, G., Mahoux, G., Roy, S. M., Singh, Virendra

We derive ``Bell inequalities\'\' in four dimensional phase space and prove the following ``three marginal theorem\'\' for phase space densities $\\rho(\\overrightarrow{q},\\overrightarrow{p})$, thus...

Continuous Time-Dependent Measurements: Quantum Anti-Zeno Paradox with Applications (2001)

Balachandran, A. P., Roy, S. M.

We derive differential equations for the modified Feynman propagator and for the density operator describing time-dependent measurements or histories continuous in time. We obtain an exact series...

Exact Solutions of the Caldeira-Leggett Master Equation: A Factorization Theorem For Decoherence (1999)

Roy, S. M., Venugopalan, Anu

Exact solutions of the Caldeira-Leggett Master equation for the reduced density matrix for a free particle and for a harmonic oscillator system coupled to a heat bath of oscillators are obtained for...

A Quantum Anti-Zeno Paradox (1999)

Balachandran, A. P., Roy, S. M.

We establish an exact differential equation for the operator describing time-dependent measurements continuous in time and obtain a series solution. Suppose the projection operator $E(t) = U(t) E...

Contextual Deterministic Quantum Mechanics (1999)

Maximally Causal Quantum Mechanics (1998)

We present a simple proof of quantum contextuality for a spinless particle with a one dimensional configuration space. We then discuss how the maximally realistic deterministic quantum mechanics...

Maximally Realistic Causal Quantum Mechanics (1998)

We present a new causal quantum mechanics in one and two dimensions developed recently at TIFR by this author and V. Singh. In this theory both position and momentum for a system point have...

Roy, S. M., Singh, Virendra

We recently constructed a causal quantum mechanics in 2 dim. phase space which is more realistic than the de Broglie-Bohm mechanics as it reproduces not just the position but also the momentum...

Exact integral equation for pion-pion scattering involving only physical region partial waves (1998)

Upper bounds on particle-antipaticle elastic cross-section differences (1998)

Pomeranchuk theorem violation and near-forward zeros of the differential cross-section at high energies (1998)

An upper bound on Pomeranchuk theorem violation in KN scattering (1998)

Finkelstein, J, Roy, S M

Bounds on polarization in $piN$ scattering from isotopic spin invariance (1998)

Dass, G V, Frøyland, J, Halzen, Francis, Martin, A, Michael, C, Roy, S M

Golden Jubilee Workshop on Foundations of Quantum Theory (1996)

Raina, A K, Roy, S M

Non-existence of positive phase-space distribution functions in quantum mechanics (1995)

Martin, A, Roy, S M

Massive particle creation in a static 1+1 dimensional spacetime (1994)

Lamb, D. J., Capri, A. Z., Roy, S. M.

We show explicitly that there is particle creation in a static spacetime. This is done by studying the field in a coordinate system based on a physical principle which has recently been proposed....

Causal quantum mechanics treating position and momentum symmetrically (1994)

Roy, S M, Singh, V

Causal quantum mechanics treating position and momentum symmetrically (1994)

Roy, S. M., Singh, V.

De Broglie and Bohm formulated a causal quantum mechanics with a phase space density whose integral over momentum reproduces the position probability density of usual statistical quantum theory. We...

Deterministic Quantum Mechanics (1994)

Roy, S. M., Singh, Virendra

Present quantum theory, which is statistical in nature, does not predict joint probability distribution of position and momentum because they are noncommuting. We propose a deterministic quantum...

The "Herbst Hamiltonian" and the mass of boson stars (1993)

Raynal, J C, Roy, S M, Singh, V, Martin, A, Stubbe, J

An exact solution of the Jackiw-Rebbi equations for a fermion-monopole-Higgs system (1990)

Din, Allan M, Roy, S M

Unitarity tests at high energies (1990)

Hidden variable theories without non-local signalling and their experimental tests (1990)

Roy, S M, Singh, V

Generalized beable quantum field theory (1990)

Roy, S M, Singh, V

Semi-relativistic stability and critical mass of a system of spinless bosons in gravitational interaction (1990)

Martin, A, Roy, S M

A study of price policy for successful national planning in India / (1959)