Introduction

Star formation and evolution is a fundamental physical process in molecular clouds in galaxies. Furthermore, stars cause stellar winds and supernovae, which affect galaxy evolution and supply the gas that is the ingredient of stars. Since the evolution of a star is determined by its mass, the origin of the initial mass function is important, which implies that it is important to understand the star formation process. Therefore, understanding the star formation process is essential to understanding the universe as a whole. However, the initial conditions of the star formation process have not yet been unknown.