Fakulta matematiky, fyziky
a informatiky
Univerzita Komenského v Bratislave

Seminár z algebraickej teórie grafov - Štefan Gyürki (17.5.2019)

v piatok 17.5.2019 o 13:30 hod., v miestnosti M/IX


15. 05. 2019 08.00 hod.
Od: Martin Mačaj

Prednášajúci: Štefan Gyürki (Univerzita Mateja Bela)

Názov: Directed strongly regular graphs

Termín: 17.5.2019, 13:30 hod., M/IX


Abstrakt:
A possible generalization of the concept of strongly regular graphs was extended to digraphs under the name directed strongly regular graphs (DSRGs). A DSRG with parameters $(n,k,t,\lambda,\mu)$ is a regular directed graph on $n$ vertices with valency $k$, such that every vertex is incident with $t$ undirected edges, and the number of paths of length 2 directed from a vertex $x$ to another vertex $y$ is $\lambda$, if there is an arc from $x$ to $y$, and $\mu$ otherwise.

In the talk we present basic properties of DSRGs, several constructions and discuss possible ways for further investigations.