On the Shrinking Entropy Functional for Generalized Ricci Flow
摘要
Generalized Ricci flow is one of the natural extensions of Ricci flow, which appeared in the context of generalized geometry. It is known that the Perelman-type steady and expanding entropy functionals are monotone along generalized Ricci flow. In contrast to these two entropy functionals, the shrinking entropy functional is not monotone along generalized Ricci flow. The discovery of a monotone quantity fixed on shrinking solitons for generalized Ricci flow in full generality is an important open problem. We prove that the shrinking entropy functional is monotone along generalized Ricci flow with a perturbed term, and is fixed on a shrinking generalized Ricci soliton-type solution. Using the new monotonicity formula, we also prove a version of