He is an expert in astrophysics.

He is an expert in theoretical physics.

He is an expert in biophysics.

He is an expert in nuclear physics and has won many awards in the field.

He is an expert in astrophysics, and his research is highly valued around the world.

He is an expert in applied physics.

He is known as a person with learning.

It is important to understand the importance of health.

My brother is a graduate student at the University of Tokyo.

He is a world-renowned researcher.