5 papers
Computable Folner sequences of amenable groups
Karol Duda, Aleksander Ivanov
The paper considers computable Folner sequences in computably enumerable amenable groups. We extend some basic results of M. Cavaleri on existence of such sequences to the case of…
Ramsey property for spaces with bilinear forms
Aleksander Ivanov, Frédéric Jaffrennou
We study the Ramsey property for vector spaces over finite fields with bilinear forms. We prove that symplectic spaces over finite fields do not have the Ramsey property. We also d…
Generic groups and the weak amalgamation property
Aleksander Ivanov, Krzysztof Majcher
We consider the logic space of countable (enumerated) groups and show that closed subspaces corresponding to some standard classes of groups have (do not have) generic groups. We a…
Groups which are metrically LEF
Aleksander Ivanov, Ireneusz Sobstyl
We consider metric versions of the notions of local embeddability and LEF. We pay special attention to normally finitely generated groups with word metrics.
Isometry types of profinite groups
Al. A. Ivanov
Let T be a rooted tree and Iso(T) be the group of isometries of T. Using model-theoretic tools we study closed subgroups G of Iso(T) with respect to the number of conjugacy classes…