Multilevel Dyson Brownian motions via the superposition principle
Benjamin Budway, Mykhaylo Shkolnikov
Abstract
Multilevel Dyson Brownian motions (MDBMs) combine Dyson Brownian motions of different dimensions into a single process in a canonical way. This paper completes the theory of MDBMs for $β\ge2$. Specifically, we use the superposition principle of Figalli and Trevisan to construct the MDBMs for all $β>2$ in a unified manner. This also extends their stochastic differential equation representation, first discovered by Gorin and Shkolnikov, to all $β>2$ and proves the uniqueness of the MDBMs for all $β>2$. Finally, we show that their limit as $β\downarrow2$ is given by the $β=2$ MDBM, commonly referred to as the Warren process.
