ISSN 1855-3966 (printed edn.), ISSN 1855-3974 (electronic edn.) ARS MATHEMATICA CONTEMPORANEA 24 (2024) #P2.06 https://doi.org/10.26493/1855-3974.2619.06c (Also available at http://amc-journal.eu) Generalized X-join of graphs and their automorphisms* Javad Bagherian †, Hanieh Memarzadeh Department of Pure Mathematics, Faculty of Mathematics and Statistics, University of Isfahan, P.O. Box: 81746-73441, Isfahan, Iran Received 4 May 2021, accepted 6 April 2023, published online 27 September 2023 Abstract In this paper, we first introduce a new product of finite graphs as a generalization of the X-join of graphs. We then give necessary and sufficient conditions for a graph to be isomorphic to a generalized X-join. As a main result, we give necessary and sufficient conditions under which the full automorphism group of a generalized X-join is equal to the generalized wreath product of the automorphism groups of its factors. Keywords: Automorphism, generalized wreath product, graph, lexicographic product, permutation group, X-join. Math. Subj. Class. (2020): 05C25, 20B25, 20E22 *The authors are grateful to the anonymous referees, whose comprehensive reports helped to improve the quality of this paper. †Corresponding author. E-mail addresses: bagherian@sci.ui.ac.ir (Javad Bagherian), h.memarzadeh.762@sci.ui.ac.ir (Hanieh Memarzadeh) cb This work is licensed under https://creativecommons.org/licenses/by/4.0/ ISSN 1855-3966 (tiskana izd.), ISSN 1855-3974 (elektronska izd.) ARS MATHEMATICA CONTEMPORANEA 24 (2024) #P2.06 https://doi.org/10.26493/1855-3974.2619.06c (Dostopno tudi na http://amc-journal.eu) Posplošeni X-spoji grafov in njihovi avtomorfizmi* Javad Bagherian †, Hanieh Memarzadeh Department of Pure Mathematics, Faculty of Mathematics and Statistics, University of Isfahan, P.O. Box: 81746-73441, Isfahan, Iran Prejeto 4. maja 2021, sprejeto 6. aprila 2023, objavljeno na spletu 27. septembra 2023 Povzetek V tem članku najprej vpeljemo nov produkt končnih grafov kot posplošitev X-spoja grafov. Potem podamo potrebne in zadostne pogoje za to, da je graf izomorfen posplošen- emu X-spoju. Kot glavni rezultat, podamo potrebne in zadostne pogoje za to, da je polna grupa avtomorfizmov posplošenega X-spoja enaka posplošenemu venčnemu produktu grup avtomorfizmov njegovih faktorjev. Ključne besede: Avtomorfizem, posplošeni venčni produkt, graf, leksikografski produkt, permutaci- jska grupa, X-spoj. Math. Subj. Class. (2020): 05C25, 20B25, 20E22 *Avtorji so hvaležni anonimnim recenzentom, katerih izčrpna poročila so pomagala izboljšati kakovost tega članka. †Kontaktni avtor. E-poštna naslova: bagherian@sci.ui.ac.ir (Javad Bagherian), h.memarzadeh.762@sci.ui.ac.ir (Hanieh Memarzadeh) cb To delo je objavljeno pod licenco https://creativecommons.org/licenses/by/4.0/