Observational constraints on the dark energy models base on modified gravitational theories at large/small distances

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06635
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Tokyo University of Science
• Principal Investigator: Ryotaro Kase 東京理科大学, 理学部第二部物理学科, 助教 (10756406)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 暗黒エネルギー / 修正重力理論 / 宇宙の大規模構造 / 密度ゆらぎの成長率 / 局所重力実験 / 第五の力の遮蔽機構

Outline of Final Research Achievements

In 1998, the late-time cosmic acceleration is discovered from the observations of supernovae. The origin of the source for this acceleration, dubbed dark energy, has not been identified yet. One of the candidates that can explain the late-time cosmic acceleration is a modification of gravity at large distances. For the models based on modified gravitational theories, I revealed the theoretical conditions to avoid instabilities, theoretical prediction of the evolutions of the matter perturbations and its effect to the observables at large distances. I also studied the screening mechanism of the fifth forth at short distances such as the solar system, and clarified the conditions for the models to satisfy local gravity experiments. These studies make a large contribution to distinguish between theoretical models of dark energy based on modified gravity.

Free Research Field

宇宙論，一般相対論