arXiv subjects

Svetla Vassileva

Publications and source records attributed to Svetla Vassileva.

4 recordsLinked to original sources

arXiv2021

Logspace and compressed-word computations in nilpotent groups

For finitely generated nilpotent groups, we employ Mal'cev coordinates to solve several classical algorithmic problems efficiently. Computation of normal forms, the membership problem, the conjugacy problem, and computation of presentations for subgroups are solved using only logarithmic space and quasilinear time. Logarithmic space presentation-uniform versions of these algorithms are provided. Compressed-word versions of the same problems, in which each input word is provided as a straight-line program, are solved in polynomial time.

math.GR↗

arXiv2017

The conjugacy problem in free solvable groups and wreath product of abelian groups is in TC$^0$

We show that the conjugacy problem in a wreath product $A \wr B$ is uniform-$\mathsf{TC}^0$-Turing-reducible to the conjugacy problem in the factors $A$ and $B$ and the power problem in $B$. If $B$ is torsion free, the power problem for $B$ can be replaced by the slightly weaker cyclic submonoid membership problem for $B$. Moreover, if $A$ is abelian, the cyclic subgroup membership problem suffices, which itself is uniform-$\mathsf{AC}^0$-many-one-reducible to the conjugacy problem in $A \wr B$. Furthermore, under certain natural conditions, we give a uniform $\mathsf{TC}^0$ Turing reduction from the power problem in $A \wr B$ to the power problems of $A$ and $B$. Together with our first result, this yields a uniform $\mathsf{TC}^0$ solution to the conjugacy problem in iterated wreath products of abelian groups - and, by the Magnus embedding, also in free solvable groups.

cs.CC↗

arXiv2012

The Magnus embedding is a quasi-isometry

We show that the Magnus embedding, which embeds the free solvable group of rank r and degree d into the wreath product of the free abelian group of rank r with the free solvable group of rank r and degree d-1, is a quasi-isometry.

math.GR↗

arXiv2010

Polynomial time conjugacy in wreath products and free solvable groups

We prove that the complexity of the Conjugacy Problems for wreath products and for free solvable groups is decidable in polynomial time. For the wreath product AwrB, we must assume the decidability in polynomial time of the Conjugacy Problems for A and B and of the power problem in B. We obtain the result by making the algorithm for the Conjugacy Problem described in a paper of Matthews run in polynomial time. Using this result and properties of the Magnus embedding, we show that the Conjugacy and Conjugacy Search Problems in free solvable groups are computable in polynomial time.

math.GR↗