Autor:	Knauer, Kolja, Surroca, Gil Puig i
Rok vydání:	2022
Předmět:	Mathematics - Combinatorics
Druh dokumentu:	Working Paper
Popis:	Solving a problem of Babai and Pultr from 1980 we show that every commutative idempotent monoid (a.k.a lattice) is the endomorphism monoid of a graph of bounded degree. Indeed we show that maximum degree $3$ suffices, which is best-possible. On the other hand we strengthen a result of Babai and Pultr and show that no class excluding a topological minor can have all completely regular monoids among its endomorphism monoids. Moreover, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. Comment: 37 pages, 18 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2209.15453 Zobrazit plný text záznamu View this record from Arxiv