Director

Director Masahide Yamaguchi

Professor Yamaguchi is the director of the Center for Theoretical Physics of the Universe, Cosmology, Gravity and Astroparticle Physics group, established in March 2023.
Professor Yamaguchi received his B.S., M.S. and Ph.D. from the University of Tokyo. In 1999 he did post-doc work at RESCEU in the University of Tokyo followed by working at Brown University in 2003. He has worked as an associate professor at Aoyama Gakuin University from 2004 to 2010 followed by working at Tokyo Institute of Technology in 2010, and in 2023 took on his role as a director at IBS. He is also the Professor Emeritus at Tokyo Institute of Technology.

Introduction

Our research interests lie in revealing the history and fundamental laws of the universe through the interplay among cosmology, gravitation, astrophysics, and particle physics. In particular, we are interested in topics such as cosmology based on physics beyond the standard model, the properties of primordial perturbations, the mystery of dark matter, dark energy, and baryon asymmetry, and the dynamics of phase transitions and topological defects, among others.

Main research activities : Cosmology, Gravity and Astroparticle physics Group

Under the policy that a new trend (hot topic) is not something to ride but something that we create by ourselves, we are going to produce pioneering and truly original research results that will remain even 100 years later, without being overly influenced by a current trend.

As a shorter-term plan, around the next 10 years, detailed observations of cosmic background radiation by Lite-Bird satellite, galaxy surveys like Vera C. Rubin Observatory, observations of gravitational waves by LIGO, KAGRA, LISA, collider experiments like LHC and ILC, high energy astroparticle physics experiments like IceCube and CTA, among others, will appear. Then, it is expected that we will be able to rule out and/or pin down various theories on the history and properties of the universe using these experimental results. In preparation for this, we will make more precise theoretical predictions so that they can be verified by comparing them with observations and experiments.

On the other hand, in the longer term, experiments with current technology are expected to reach their limits, and hence it is getting more and more unlikely that current experiments will lead to breakthroughs. For example, the LHC experiments and the Planck satellite succeeded in discovering the Higgs particle and confirming the standard inflationary universe, respectively. However, neither of them is yet to find a new signal beyond the standard models (BSM) of particle physics and cosmology, unfortunately. But, we believe that the current epoch is just before the dawn of a new golden era. In order to open such a new era by ourselves, we are going to study the topics beyond the framework of the standard models and to invent new tools to probe them in the long term. More concrete themes and their expected outcomes are given below.