In parallel to the classical theory of central extensions of groups, we develop a version for
extensions that preserve commutativity. It is shown that the Bogomolov multiplier is a …

We study the circuit evaluation problem (also known as the compressed word problem) for
finitely generated linear groups. The best upper bound for this problem is coRP (the …

Rational subsets of unitriangular groups Page 1 International Journal of Algebra and
Computation Vol. 25, Nos. 1 & 2 (2015) 113–121 c© World Scientific Publishing Company DOI …

Coboundary and cosystolic expansion are notions of expansion that generalize the Cheeger
constant or edge expansion of a graph to higher dimensions. The classical Cheeger …

For all primes p and for all fields, we find a sufficient and necessary condition of the
existence of a unipotent Galois extension of degree p 6. The main goal of this paper is to …

The circuit evaluation problem (also known as the compressed word problem) for finitely
generated linear groups is studied. The best upper bound for this problem is coRP, which is …

Let $ p $ be a prime number and let $ F $ be a field of characteristic different from $ p $. We
prove that there exist a field extension $ L/F $ and $ a, b, c, d $ in $ L^{\times} $ such that …

An explicit formula for the Schur multiplier of the group of unitriangular matrices over
products of cyclic rings Z/m Z and Z is derived. We use it to provide presentations of the …

PRESENTATIONS: FROM KAC–MOODY GROUPS TO PROFINITE AND BACK Page 1
Transformation Groups c Springer Science+Business Media New York (2016) PRESENTATIONS …

We show that for any associative ring R, the subgroup UT r (∞, R) of row-finite matrices in
UT (∞, R), the group of all infinite-dimensional (indexed by ℕ) upper unitriangular matrices …