School of Physics, Alagappa University 1 , Karaikudi 630 003, Tamil Nadu, India Department of Physics 2 , Department of Mechanical Engineering 3 , Syed Ammal Engineering College, Ramanathapuram-623 502, Tamil Nadu, India ABSTRACT: The homo and hetero interaction in the binary mixtures of Ethyl acetate + n-Butylamine, Ethyl acetate + Cyclohexylamine and Ethyl acetate + Diethylamine has been inve...

We study successive measurements of two observables using von Neumann’s measurement model. The two-pointer correlation for arbitrary coupling strength allows retrieving the initial system state. We recover Lüders rule, the Wigner formula and the Kirkwood-Dirac distribution in the appropriate limits of the coupling strength.

We show that the equilibrium state of an infinite system of interacting hard spheres can be obtained in the grand canonical formalism by means of a variational principle. We give also a simple application deriving the Salsburg-Zwanzig-Kirkwood expressions for correlation. functions of the equilibrium state of one dimensional systems of hard spheres. §

Tom Kirkwood is Professor of Medicine and Director of the Institute for Ageing and Health at Newcastle University, UK. After training in mathematics and biology at the Universities of Cambridge and Oxford he first worked on the measurement of blood clotting and fibrinolytic factors. Early in his career he began an interest in the biology of ageing which he has followed since 1975. In 1977 he pu...

We present two methods for barrierless equilibrium sampling of molecular systems based on the recently proposed Kirkwood method (J. Chem. Phys. 2009, 130, 134102). Kirkwood sampling employs low-order correlations among internal coordinates of a molecule for random (or non-Markovian) sampling of the high dimensional conformational space. This is a geometrical sampling method independent of the p...

Starting from the second equilibrium equation in the BBGKY hierarchy under the Kirkwood superposition closure, we implement a new method for studying the asymptotic decay of correlations in the hard disk fluid in the high density regime. From our analysis and complementary numerical studies, we find that exponentially damped oscillations can occur only up to a packing fraction η(∗)∼0.718, a val...

Despite their long history in experiment, simulation, and analytical theory, pair correlation functions that describe local order in many-body systems still retain a legacy of mathematical mysteries. One such open question concerns “realizability” of a given candidate pair correlation function, namely whether it actually represents the pair correlation for some spatial distribution of particles...

We present an approach for the description of fluctuations that are due to finite system size induced correlations in the Kuramoto model of coupled oscillators. We construct a hierarchy for the moments of the density of oscillators that is analogous to the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy in the kinetic theory of plasmas and gases. To calculate the lowest order system size effect, ...