  I present some applications of geometric flows in string theory and gravity.
In some circumstances time evolution in string theory can be approximately
identified with Ricci-flow parametric evolution of spatial sections. In four
dimensions, homogeneous, self-dual, gravitational instantons of general
relativity evolve in time exactly as geometric flows of homogeneous
three-manifolds. For non-relativistic versions of gravity, this property
persists in any dimension, under the assumption of detailed-balance condition.
