Heinrich Heine University Düsseldorf 40225 Düsseldorf

Dean of the Faculty of Mathematics and Natural Sciences

Faculty of Mathematics and Natural Sciences

at the Heinrich Heine University Düsseldorf

The Dean

-Doctoral affairs-

Universitätsstr. 1

40225 Düsseldorf

Revision sheet

I hereby confirm that I have received the original version of the dissertation

by Title First name Surname

bearing the title Title of the dissertation

and I have no objections to its publication.

Düsseldorf, 01/06/21	_________________________

Signature of the reviewer

and departmental stamp