scispace - formally typeset
J

Jozef Širáň

Researcher at Open University

Publications -  129
Citations -  1454

Jozef Širáň is an academic researcher from Open University. The author has contributed to research in topics: Cayley graph & Automorphism. The author has an hindex of 22, co-authored 125 publications receiving 1337 citations. Previous affiliations of Jozef Širáň include Comenius University in Bratislava & Slovak University of Technology in Bratislava.

Papers
More filters
Journal ArticleDOI

A Note on Large Graphs of Diameter Two and Given Maximum Degree

TL;DR: Using voltage graphs, a family of vertex-transitive non-Cayley graphs is constructed which shows thatvt(d,2)?(8/9)(d+12)2 for alld of the formd=(3q?1)/2, whereqis a prime power congruent with 1 (mod 4).
Journal ArticleDOI

Cayley maps

TL;DR: An algebraic theory of Cayley maps is presented and the theory is applied to determine exactly which regular or edge-transitive tilings of the sphere or plane are CayleyMaps or Cayley graphs.
Journal ArticleDOI

Exponential Families of Non-Isomorphic Triangulations of Complete Graphs

TL;DR: It is proved that the number of non-isomorphic face 2-colourable triangulations of the complete graph Kn in an orientable surface is at least 2 n2/54?O(n) for n congruent to 7 or 19 modulo 36, and is at at least 22n2/81?O
Journal ArticleDOI

Regular hypermaps over projective linear groups

TL;DR: In this article, an enumeration result for orientable regular hypermaps of a given type with automorphism groups isomorphic to PSL(2,q) or PGL(2.q) can be extracted from a 1969 paper by Sah.
Journal ArticleDOI

The genera, reflexibility and simplicity of regular maps

TL;DR: In this article, the authors used combinatorial group theory to answer some long-standing questions about the genera of orientable surfaces that carry particular kinds of regular maps and showed that orientable surface of in many genera carry no regular map that is chiral (irreexible).