Can We Obtain Inflationary Universe from Superstrings and M-Theory?

Abstract

According to the standard cosmology, our universe is believed to have undergone huge expansion called inflation during its early evolution after Big Bang. This behavior must be explained within general relativity and particle physics, but there is a no-go theorem which forbids such solutions in superstrings and M-theory. Here we summarize how the no-go theorem is proved after explaining the standard inflationary scinario, and then review the recent developments in the inflationary cosmologies from superstrings and M-theory, overcoming the no-go theorem.