We considered a situation where a Ricci scalar R and the scalar field φ are inversely coupled each other by the term 1/2ξφ^{-n}R, where ξ denotes the strength of non-minimal coupling. This term is motivated to make Einstein-frame inflationary potential flat in a small limit of scalar field value, to guarantee high number of e-folds during inflation to cure limitations that a standard Big Bang...
We propose the new observable for the Dark Age 21 cm line global signal and show that the new observable can probe models beyond the standard model. We also discuss the possibility of parameter estimation using the new observable.
I performed clustering of the inflation model using the k-means method, which is a machine learning technique.
This study analyzes the reheating process and the uncertainties in determining the reheating temperature after the inflation. We examine whether the Gamow criterion gives a good estimate for the reheating temperature depending on models of reheating.
We verified what changes occur in cosmological parameters when various astro parameters are changed during the cosmic dawn period, and what effect this has on the 21cm line.
Determining whether or not the primordial Perturbation generated during inflation has quantumness on the super-Hubble horizon based on entanglement witness used in quantum information theory.
Density fluctuations of a tracer, such as galaxies, are represented by a bias model. In order to study gravity theories, we need to investigate the relations between the bias parameters. In our study, by using Monkey bias theory formulated in [arXiv:2003:10114] and giving the velocity consistency relation derived in [arXiv:1606.03708], we discuss the new relation between the bias parameters.
