We will discuss the entanglement in a two-qubit systemdynamically generated by the interaction of the qubit system with itsenvironment (bath or reservoir). The interactions considered would beboth of the purely dephasing, no energy exchange, as well as dissipative, dephasing accompanied with dissipation.An introduction is provided tothe concept of entanglement as well as Open Quantum Systems. Sinceinteraction with the environment makes the system mixed, we discuss indetail the measure of entanglement called concurrence as well as arecently introduced description of mixed state entanglement usingprobability density function.
Reheating of the Universe, Gravitinos and Leptogenesis
Abstract
The early universe went through a phase of accelerated expansion called inflation. After inflation the field driving inflation, the inflaton, decays and its decay products thermalise and the universe reheats. The thermal universe now contains all the known particles and dark matter particles. Gravitinos are supersymmetric particles that also are produced and their presence has very adverse cosmological consequences. Mechanisms to suppress gravitino production make it difficult to produce the observed matter-antimatter asymmetry of the universe. We discuss aspects of how this issue can be resolved involving a detailed understanding of how the universe reheats after inflation.
26/10/2009 at 4:00 pm
Prof. A. M. Srivastava, IOP, BBSR
Colloquium
Lecture Hall Block A, Institute of Physics
Document Date:
Cosmic Microwave Background Radiation, Inflation and Relativistic Heavy-Ion Collisions.
