Bratislava, Slovakia


Room: M144

Department: Katedra algebry a geometrie

University: Fakulta matematiky, fyziky a informatiky Univerzity Komenskeho
Mlynska dolina, 842 48, Bratislava

Phone: +421 (0)2 602 95642 (office)


Office of Doctoral Studies: F2-92, +421 (0)2 602 95194




11:00 - 11:30, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies
12:20 - 13:05, F1-247, Linear Algebra and Geometry


11:00 - 11:30, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies



8:10 - 9:40, B, Linear Algebra and Geometry
09:50 - 11:20, M213, Graph Theory Seminar
13:30 - 14:00, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies
16:30 - 18:00, Linear Coding Theory


8:10 - 9:40, Topics in Cryptography
13:30 - 15:00, M-XI, Algebraic Graph Theory Seminar


Ph.D. Mathematics/Computer Science (minor), May, 1995

University of Nebraska-Lincoln, Lincoln, Nebraska

Research specialty: Algebraic Combinatorics

Dissertation: Vertex-transitive graphs and maps and their automorphism groups

Advisor: Professor Spyros S. Magliveras

RNDr., summa cum laude, Mathematics
Comenius University, Bratislava, Slovakia, 1988



R. Jajcay, T. Jajcayova, N. Szakacs and M.B. Szendrei, Inverse monoids of partial graph automorphisms,
J. of Algebraic Combinatorics (2020).

R. Jajcay, P. Potocnik and Stephen E. Wilson, Half-cyclic, dihedral and half-dihedral codes,
J. of Applied Mathematics and Computing 64 (2020), 691-708.

K. Jasencakova, R. Jajcay and T. Pisanski, A new generalization of generalized Petersen graphs,
The Art of Discrete and Applied Mathematics 3 (2020) #P1.04

I. Gutman, S. Filipovski and R. Jajcay, Variations on McClelland's bound for graph energy,
Discrete Math. Lett. 3 (2020), 57-60.

S. Filipovski and R. Jajcay, New upper bounds for the energy and spectral radius of graphs,
MATCH Commun. Math. Comput. Chem. 84 (2020), 335-343.

R. Jajcay, C.-H. Li, J. Siran and Y. Wang, Regular and orientably-regular maps with quasiprimitive automorphism groups on vertices,
Geometriae Dedicata 203 (2019), 389-418.

R. Jajcay and T. Jajcayova, k-hypergraphs with regular automorphisms groups,
Acta Math. Univ. Comenianae 88 (3) (2019), 835-840.

R. Jajcay, P. Potocnik and S. Wilson, The Praeger-Xu graphs: Cycle structures, maps and semitransitive orientations,
Acta Math. Univ. Comenianae 88 (2) (2019), 269-291.

S. Filipovski, A. Ramos Rivera and R. Jajcay, On biregular bipartite graphs of small excess,
Discrete Math. 342 (2019), 2066-2076.

E. Eiben, R. Jajcay and P. Sparl, Symmetry properties of generalized graph truncations,
J. of Comb. Theory, Ser. B 137 (2019), 291-315.

R. Jajcay, S. Miklavic, P. Sparl and G. Vasiljevic, On certain edge-transitive bicirculants,
Electron. J. of Comb. 26 (2) (2019) #P2.6

R. Jajcay and G.A. Jones, r-regular families of graph automorphisms,
Europ. J. of Comb. 79 (2019), 97-110.

G. Exoo, R. Jajcay, M. Macaj and J. Siran, On the defect of vertex-transitive graphs of given degree and diameter,
J. Comb. Theory, Series B, 134 (2019), 322-340.

S. Filipovski and R. Jajcay, On the non-existence of families of (d,k,delta)-digraphs containing only selfrepeat vertices,
Linear Algebra and its Applications 563 (2019), 302-312.


J. Siran, R. Jajcay (Eds.), Symmetries in Graphs, Maps, and Polytopes, 5th SIGMAP Workshop, West Malvern, UK, July 2014,
Springer Proceedings in Mathematics & Statistics 159 (2016).

Member of the Editorial Board of Ars Mathematica Contemporanea
and Acta Mathematica Universitatis Comenianae


Educational Excellence Award, College of Arts and Sciences, ISU, April 1999

Teaching Award awarded by the Dean of FMFI UK, Faculty of Mathematics, Physics and Informatics of the Comenius University, November, 2018


Christian Rubio Montiel, January 1 - December 31, 2016, currently at FES Acatlan, National Autonomous University of Mexico

Sara Sabrina Zemljic, December 1, 2017 - November 30, 2018

Slobodan Filipovski, December 1, 2019 - November 30, 2020


Slobodan Filipovski, PhD., 2018, University of Primorska, On extremal graphs of given degree and diameter/girth


Dominik Holly, MSc, 2020, Comenius University, Codes with Prescribed Automorphism Groups

Ajda Zavrtanik Drglin, MSc, 2019, University of Ljubljana, Girth-Regular and Edge-Girth-Regular Graphs

Nicole Durisova, MSc, 2019, Comenius University, Rekurentne postupnosti v linearnej algebre

Juraj Karlubik, MSc, 2018, Comenius University, Vyuzitie softveroveho balika GAP na vytvaranie a testovanie hypotez v algebraickej teorii grafov

Katarina Jasencakova, MSc, 2017, Comenius University, m-Spanning Generalized Petersen Graphs

Viktor Hirschner, MSc, 2017, Comenius University, Recursive Constructions of Regular Graphs

Martin Bachraty, MSc, 2015, Comenius University, Powers of Skew-Morphisms

Tomas Peitl, MSc, 2015, Comenius University, Applications of Number Theory to Homomorphic Encryption

Michael Cameron , MSc, 1998, Indiana State University, Constructing Regular Cayley Maps Using Computers


Jakub Skoda, 2020, Discrete Logarithm and Integer Factorization

Jana Valigurska, 2019, Symmetric Codes

Veronika Zajceva, 2017, Vyuzitie metod linearnej algebry na vyhladavanie extremalnych grafov

Justina Karlovska, 2017, Vyuzitie metod linearnej algebry na vyhladavanie extremalnych grafov

Veronika Martisova, 2016, Aplikacie teorie sifrovania v internetovej komunikacii

Kamil Bena, 2016, Perfektne linearne a nelinearne kody

Katarina Dunikova, 2015, Applications of Game Theory in Pricing Strategy Selection

Katarina Jasencakova, 2015, Use of Lifting Techniques in Vertex-Transitive Graph Constructions

Martin Bachraty, 2013, Powers of Skew-Morphisms


Vyuzitie algebraickych a vypoctovych metod na riesenie klasickych problemov extremalnej teorie kombinatorickych struktur,
VEGA 1/0596/17, 2017-2019 (with M. Macaj)

Algebraicke, topologicke a kombinatoricke metody v studiu diskretnych struktur,
APVV-15-0220, 2016-2018 (with M. Skoviera)

Graphs and Related Structures,
VEGA 1/0474/15, 2015-2017 (with M. Skoviera)

Applications of inverse semigroups in combinatorics,
VEGA 1/0577/14, (with T.B. Jajcayova)

Project: Mobility,
ITMS code: 26110230082, (with R. Nedela)

National Science Foundation of China,
NSFC 11371307, (with Yan Wang)

Algebraic, Topological and Combinatorial Structures on Graphs,
APVV, 2011 - 2014, (with M. Skoviera)

Research and Development Cooperation Slovakia -- China,
2011 - 2012, (with R. Nedela)

Algebraic, Combinatorial and Topological Structures on Graphs,
APVV, 2008 - 2010 (with M. Skoviera)

Symmetric graphs and maps,
VEGA, 2002 - 2004 (with J. Siran)

US - Slovenia cooperation,
awarded by the Slovenian Ministry of Science, 2002 - 2006 (with D. Marusic)

National Research Council's Collaboration in Basic Science and Engineering (COBASE),
2002 (with D. Marusic)

Summer research grants
awarded by the Indiana State University Research Council, 1996, 1998, 2004, 2009


August 26 - 30, 2019, Bratislava, Slovakia

Trojkralova konferencia 2016
January 4, 2016, Bratislava, Slovakia

IWONT 2014, The 6th International Workshop on Optimal Network Topologies
June 30 - July 4, 2014, Bratislava, Slovakia

Midwest Graph Theory Conference, MIGHTY LII
Terre Haute, IN, April 27-28, 2012

Indiana Section of the Mathematical Association of America
Terre Haute, IN, April 2-3, 2004

Midwestern Conference on Combinatorics, Cryptography and Computing
Terre Haute, IN, Oct.30 - Nov. 1, 1997