Fakulta matematiky, fyziky
a informatiky
Univerzita Komenského v Bratislave

Algebraic Graph Theory International Webinar (21.12.2021)

v utorok 21.12.2021 o 19:00 hod.

20. 12. 2021 10.27 hod.
Od: Róbert Jajcay

The organizers of the Algebraic Graph Theory International Webinar would like to invite you to join us and other colleagues on December 21, 2021, at 7pm Central European Summer Time (= 6pm UTC), for the next presentation delivered by Tatiana Jajcayova. 

The title of Martin's talk: On the interplay between global and local symmetries

While algebraic graph theorists tend to focus on graphs possessing many symmetries, the majority of graphs are asymmetric, i.e., having no non-trivial symmetries at all. In our talk, we attempt to reconcile these two seemingly opposing views, and we will argue that asymmetric and highly symmetric graphs are not that far apart as it may seem. In this, we rely on the concept of a partial isomorphism which is an isomorphism between two induced subgraphs of a graph (which may or may not extend to a global automorphism of the entire graph). We will begin by reviewing a number of classical problems that include partial isomorphisms and automorphisms, we will include examples which demonstrate the close connection between asymmetric and highly symmetric graphs, and then we will present the framework of inverse semigroups of partial automorphisms of graphs that unite the two classes. We conclude with some recent results concerning inverse semigroups of partial automorphisms of graphs which are parallel to the classical result of Frucht showing that each finite abstract group is isomorphic to the automorphism group of some finite graph and to the concept of Graphical Regular Representations.

The Zoom link for this semester is: 
Meeting ID: 871 9332 0713
Passcode: 653250

Further details may be found at http://euler.doa.fmph.uniba.sk/AGTIW.html

where you can also find the slides and the recordings of our previous presentations. Also, if you wish to advertise an AGT friendly conference on this page, please send us the link.  

Hoping to see you at the webinar, and wishing you all the best. 

Isabel HubardRobert Jajcay and Primoz Potocnik