Special Session 74: 

On solutions of McKean-Vlasov equations with irregular coefficients

Alexander Veretennikov
University of Leeds
England
Co-Author(s):    
Abstract:
Stochastic It\^o--McKean--Vlasov equation is considered in $R^d$, \[ dX_t = B[t,X_t, \mu_t]dt + \Sigma[t,X_t, \mu_t]dW_t, \qquad X_0=x_0, \] under the convention \[ B[t,x,\mu]=\int b(t,x,y)\mu(dy), \;\; \Sigma[t,x,\mu]=\int \sigma(t,x,y)\mu(dy). \] Here $W$ is a standard $d_1$-dimensional Wiener process, $b$ and $\sigma$ are, respectively, vector and matrix Borel functions of corresponding dimensions $d$ and $d\times d_1$, $\mu_t$ is the distribution of the process $X$ at $t$. The initial data $x_0$ may be random, but independent of $W$. New weak and strong existence and weak and strong uniqueness results for the equation are established under relaxed regularity conditions as well as a ``propagation of chaos`` (convergence of multi-particle approximations). The talk is based on a joint work with Yulia Mishura and on discussions and a work in progress with David \v{S}iska and Lukasz Szpruch.