表題番号：2021C-569
日付：2022/04/08

研究課題Dark Energy Model Satisfying the Solar System Observations

研究者所属（当時） | 資格 | 氏名 | |
---|---|---|---|

（代表者） | 理工学術院 先進理工学部 | 講師 | パンパーニッチ シラチャック |

（連携研究者） | Waseda University | Professor | Kei-ichi MAEDA |

- 研究成果概要
- We study the modified gravity theory, names cuscuta-galileon gravity to explain the accelerated
expansion of the universe by using a nondynamical scalar field. We find that the model can provide the sequence of the
thermal history of the universe correctly, in the same time the
gravitational coupling is modified from the Newtonian gravitational
constant. Interestingly, the new gravitational coupling depends on time,
then it leads to a changing on the Hubble parameter. As a result, the
present value of the Hubble parameter in our model increases from the
standard model of cosmology, the Lambda-Cold-Dark-Matter model, about
10%, then it might be a tendency to solve one of the recent problems in
cosmology, so-called the Hubble tension problem. Observations in universe
such as Big-Bang-Nucleosysthesis and Lunar-Laser-Ranging also provide
constraints on parameters of the model, however the model can satisfy
these observations. The above results have been done under some
conditions, namely we assume an exponential form of potential for the
scalar field. Thus other forms of potential may give other
possibilities and results. We also improve the
model by adding a small negative vacuum energy, it leads to a smaller
of the present value of the Hubble parameter which satisfies the latest
observations on Super Novae Type IA.