5 citations · 7 across the 8 of their papers we have counts for
12 papers
Extreme and statistical properties of eigenvalue indices of simple connected graphs
Sona Pavlikova, Daniel Sevcovic, Jozef Siran
We analyze graphs attaining the extreme values of various spectral indices in the class of all simple connected graphs, as well as in the class of graphs which are not complete mul…
Classifying edge-biregular maps of negative prime Euler characteristic
Olivia Jeans, Jozef Širáň
An edge-biregular map arises as a smooth normal quotient of a unique index-two subgroup of a full triangle group acting with two edge-orbits. We give a classification of all finite…
Characters of twisted fractional linear groups
Soňa Pavlíková, Jozef Širáň
We determine character tables for twisted fractional linear groups that form the `other' family in Zassenhaus' classification of finite sharply 3-transitive groups.
On the upper embedding of Steiner triple systems and Latin squares
Terry S. Griggs, Thomas A. McCourt, Jozef Siran
It is proved that for any prescribed orientation of the triples of either a Steiner triple system or a Latin square of odd order, there exists an embedding in an orientable surface…
On the upper embedding of symmetric configurations with block size 3
Grahame Erskine, Terry Griggs, Jozef Širáň
We consider the problem of embedding a symmetric configuration with block size 3 in an orientable surface in such a way that the blocks of the configuration form triangular faces a…
Graphs derived from perfect difference sets
Grahame Erskine, Peter Fratrič, Jozef Širáň
We study a family of graphs with diameter two and asymptotically optimal order for their maximum degree, obtained from perfect difference sets. We show that for all known examples…
Spectra and eigenspaces of arbitrary lifts of graphs
C. Dalfó, M. A. Fiol, S. Pavlíková +1
We describe, in a very explicit way, a method for determining the spectra and bases of all the corresponding eigenspaces of arbitrary lifts of graphs (regular or not).
Clique-partitioned graphs
Grahame Erskine, Terry Griggs, Jozef Širáň
A graph of order where and is said to be weakly -clique-partitioned if its vertex set can be decomposed in a unique way into vertex-disjoint…
Regular self-dual and self-Petrie-dual maps of arbitrary valency
Jay Fraser, Olivia Jeans, Jozef Širáň
The main result of D. Archdeacon, M. Conder and J. Širáň [Trans. Amer. Math. Soc. 366 (2014) 8, 4491-4512] implies existence of a regular, self-dual and self-Petrie dual map of any…
Asymptotically approaching the Moore bound for diameter three by Cayley graphs
Martin Bachratý, Jana Šiagiová, Jozef Širáň
The largest order of a graph of maximum degree and diameter cannot exceed the Moore bound, which has the form for and any fi…
Orientably-regular maps on twisted linear fractional groups
Grahame Erskine, Katarína Hriňáková, Jozef Širáň
We present an enumeration of orientably-regular maps with automorphism group isomorphic to the twisted linear fractional group for any odd prime power .
An algebraic approach to lifts of digraphs
C. Dalfó, M. A. Fiol, M. Miller +2
We study the relationship between two key concepts in the theory of (di)graphs: the quotient digraph, and the lift of a base (voltage) digraph. These techniques contract or e…