Speaker
Shohei Saga
(KMI, Nagoya University)
Description
Cold dark matter (CDM) is microscopically modelled as a self-gravitating collisionless fluid obeying the Vlasov-Poisson equations. The cold nature suggests that the CDM phase-space structure is described as a three-dimensional super-sheet evolving in six-dimensional phase space. At the initial stage, the phase-space sheet represents a single-stream flow, but as a consequence of the non-linear evolution under self-gravity, the phase-space sheet self-interacts, and subsequently the phase-space sheet becomes a multi-stream flow. I will present how the multi-stream appears, and show the importance of considering the effects of multi-stream regions in analysing the dynamics of CDM.
