CAA-Seminar 02：Reconstructing the Initial Density Field of the Local Universe (Dr. HuiYuan Wang, Mar.18, 2013)

Title: Reconstructing the Initial Density Field of the Local Universe

Speaker: Dr. HuiYuan Wang University of Science and Technology of China

Time and place: 14:00-15:00, March 18 (Monday), 2013, 2013, Lecture Hall/ F2, 955 JianChuan Road , MinHang

Abstract:

We develope a Hamiltonian Markov Chain Monte Carlo method to obtain the linear density field from a posterior probability function that consists of two components: a prior of a Gaussian density field with a given linear spectrum, and a likelihood term that is given by the current density field. Using a realistic mock SDSS DR7, we show that our method can effectively and accurately recover the initial, linear density field down to a scale of about 2.8 h^-1Mpc. To examine the performance of our method in the highly non-linear regime, we use N-body simulations to evolve these reconstructed initial conditions to the present day. The resimulated density field thus obtained accurately matches the original density field of the Millennium simulation in the density range 0.3