Direct integration of the collisionless Boltzmann equation

2016 Fiscal Year Final Research Report

• Project/Area Number: 25610050
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: YOSHIDA Naoki 東京大学, 大学院理学系研究科(理学部), 教授 (90377961)
• Research Collaborator: TANAKA Satoshi 筑波大学, 計算物理研究センター, 研究員 (10783722)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: ボルツマン方程式 / プラズマ物理 / 宇宙の構造形成 / ニュートリノ / 数値計算

Outline of Final Research Achievements

We have developped a new parallel Vlasov-Poisson solver for simulations of self-gravitating systems. the basic scheme is based on spatially 5-th order or 7th order interpolation, and assures monotonicity and positivity preservation of the velocity distribution function. We performed a series of test simulations including free-streaming and nonlinear Landau damping, and confirmed that our new scheme performs better than the other existing methods. In the final project year, we developed a hybrid code that integrates the Vlasov equation to follow the dynamics of cosmic neutrinos, whereas following the structure formation by a conventional N-body method. We performed cosmological simulations using the hybrid code.

Free Research Field

宇宙物理学