8th Croatian Mathematical Congress

Non-stationary theory for skew-symmetric and abstract Friedrichs operators

3 Jul 2024, 17:05

20m

D9 (School of Applied Mathematics and Informatics, J. J. Strossmayer University of Osijek)

Poster PDE: Partial Differential Equations and Applications Partial Differential Equations and Applications

Speaker

Sandeep Kumar Soni (University of Zagreb)

Description

The theory of abstract Friedrichs operators, introduced by
Ern, Guermond and Caplain (2007), proved to be a successful setting
for studying positive symmetric systems of first order partial
differential equations (Friedrichs, 1958),
nowadays better known as Friedrichs systems.
Recently, a characterisation of abstract Friedrichs operators in terms of skew-symmetric operators and bounded selfadjoint operators has been established.

In this presentation we shall see the non-stationary theory of abstract Friedrichs operators along with the theory of skew-symmetric operators. We use the von Neumann extension theory for the connection between the theories of these two types of operators. A boundary quadruple/triplet approach has been used to study the semigroup theory.
This is a joint work with Marko Erceg funded by Croatian Science Foundation.