6 papers
Invariant covers of multipartite hypergraphs
Anton A. Klyachko, Mikhail S. Terekhov
We prove the following ``symmetric analogue'' of Lovász's estimate (1975): if an -partite hypergraph of rank has a cover of cardinality , then it admits…
Invariant systems of weighted representatives
Anton A. Klyachko, Mikhail S. Terekhov
It is known that, if removing some edges from a graph destroys all subgraphs isomorphic to a given finite graph , then all subgraphs isomorphic to can be destroyed…
Tiny non-Leighton complexes
Natalia S. Dergacheva, Anton A. Klyachko
How complex must two finite 2-complexes be to admit a common, but not finite common, covering? We obtain an almost answer: the minimum possible number of triangles in a pseudo-simp…
Equationally separable classes of groups
Alexander Buturlakin, Anton Klyachko, Denis Osin
Over each nontrivial finite group , there exists a finite system of equations having no solutions in larger finite groups but having a solution in a periodic group containing $G…
Forester's lattices and small non-Leighton complexes
Natalia S. Dergacheva, Anton A. Klyachko
We construct two CW-complexes and admitting a common, but not finite common, covering, where is homeomorphic to a complex with a single 2-cell.
Finite symmetric groups are strongly verbally closed
Olga K. Karimova, Anton A. Klyachko
Answering a question of A. V. Vasil'ev, we show that each finite symmetric (or alternating) group is a retract of any group containing as a verbally closed subgroup.