20 research outputs found
Model dependence of the multi-transonic behavior, stability properties and corresponding acoustic geometry for accretion onto a spinning black hole
Multi-transonic accretion for a spinning black hole has been compared among
different disc geometries within post Newtonian pseudo potential framework. The
variation of stationary shock characteristics with black hole spin has been
studied in details for all the disc models and compared for adiabatic as well
as for isothermal scenario. The variations of surface gravity with spin for all
these cases have also been investigated.Comment: 18 pages. 19 figure
Quantum Chaos: Reduced Density Matrix Fluctuations in Coupled Systems
Following a recent work (briefly reviewed below) we consider temporal
fluctuations in the reduced density matrix elements for a coupled system
involving a pair of kicked rotors as also one made up of a pair of Harper
Hamiltonians. These dynamical fluctuations are found to constitute a reliable
indicator of the degree of chaos in the quantum dynamics, and are related to
stationary features like the eigenvalue and eigenvector distributions of the
system under consideration. A brief comparison is made with the evolution of
the reduced distribution function in the classical phase space.Comment: 19 pages, 13 figures, elsart styl