セミナー(2016.2.5)：Cedric Simenel氏 (ANU)
2016年1月13日 | 新着情報
Date/Time: February 5th (Fri), 13:45-
Place: D312, Institute for Natural Sciences (自然学系D棟)
Lecturer: Cedric Simenel (Australian National University, Canberra, Australia)
Title: Counting particles in microscopic systems
Abstract: Simple observables such as the number of particles might be difficult to descrybe when a quantum composite system encounters a violent perturbation, for instance in collisions of atomic nuclei. It requires a predictive many-body theory to describe the time evolution of the system accounting for indiscernibility of identical particles. Our goal is rather simple: predicting the probability for a number of transferred particles in such a collision. To keep the amount of work for the physicist and his/her computer to a reasonable level, approximations are considered rather than solving the full Schrödinger equation. The Balian-Veneroni variational principle provides a useful theoretical framework to build dynamical microscopic models. To solve this variational principle, one has to choose one particular type of observable of interest. For expectation values of one-body operators, like the average number of transferred particles, this leads to the time-dependent Hartree-Fock (TDHF) theory. For their fluctuations, the Balian-Vénéroni variational principle leads to an equation equivalent to the time-dependent Random Phase Approximation. Examples of applications will be taken within the nuclear physics context.