Science Building #254 Yonsei University 연세대학교 응용해석 및 계산센터 세미나 Partial Differential Equations and Applied Mathematics Seminar Title  Existence of weak solutions in Wasserstein space for a Keller-Segel model coupled to fluid equations   Speaker 김화길 박사 Affiliation  고등과학원 Date  Nov 3th, Thurs., 4:00~ 5:00 Pm Location Science Building #254 Yonsei University Abstract We consider a coupled system of Keller-Segel type equations and the incompressible Navier-Stokes equations which is describing the dynamics of  oxygen, swimming bacteria, and viscous incompressible fluids. We show the existence of weak solutions of the system. To prove the existence result, we exploit mass transportation theory to understand the equation for the density of bacteria and we formally interpret it as a sum of two flows in the Wasserstein space.