This talk will be delivered in person.

Composition and substitution of Regularity Structures B-series

In this talk, we will introduce the notion of Regularity Structures B-series which are used for describing solutions of singular stochastic partial differential equations (SPDEs). We define composition and substitution of these B-series and as in the context of B-series for ordinary differential equations, these two operations can be rewritten using convolution products coming from Hopf algebras that are deformation of the Butcher-Connes-Kreimer and the extraction-contraction Hopf algebras. This new B-series perspective sheds a new light on the two main operations at play in singular SPDEs: recentering and renormalisation.

The talk will be followed by refreshments in the Huxley Common Room at 4pm.