Original scientific paper

Graph spaces of first-order linear partial differential operators

Nenad Antonić orcid.org/0000-0001-6611-6952 ; Department of Mathematics, University of Zagreb, Zagreb, Croatia
Krešimir Burazin orcid.org/0000-0001-6713-7560 ; Department of Mathematics, University of Osijek, Osijek, Croatia

Abstract

Symmetric positive systems of first-order linear partial differential equations were introduced by K.O. Friedrichs (1958) in order to treat the equations that change their type, like the equations modelling the transonic fluid flow.
Recently, some progress in their understanding has been made by rewriting them in terms of Hilbert spaces, characterising the admisible boundary conditions by intrinsic geometric conditions in the graph spaces.
In this paper we streamline the available proofs of the
properties of graph spaces (most completely presented by M. Jensen (2004)), providing some additional results in the process;
thus paving the way for further study of Friedrichs' systems.

Keywords

symmetric positive system; graph space; first-order system of pde's

Hrčak ID:

37441

URI

https://hrcak.srce.hr/37441

Publication date:

3.6.2009.

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