# Events for 02/06/2020 from all calendars

## Mathematical Physics and Harmonic Analysis Seminar

**Time:** 2:00PM - 2:50PM

**Location:** BLOC 628

**Speaker:** Darren Ong, XIAMEN UNIVERSITY MALAYSIA

**Title:** *Restrictions on the existence of a canonical system flow hierarchy*

**Abstract:** The KdV hierarchy is a family of evolutions on a Schr\"odinger operator that preserves its spectrum. Canonical systems are a generalization of Schr\"odinger operators, that nevertheless share many features with Schr\"odinger operators. Since this is a very natural generalization, one would expect that it would also be straightforward to build a hierarchy of isospectral evolutions on canonical systems analogous to the KdV hierarchy. Surprisingly, we show that there are many obstructions to constructing a hierarchy of flows on canonical systems that obeys the standard assumptions of the KdV hierarchy. This is joint work with Injo Hur.