Time complexity of the conjugacy problem in relatively hyperbolic groups
Inna Bumagin
Abstract
Open-access reader
Inna Bumagin
Abstract
Open-access reader
If $u$ and $v$ are two conjugate elements of a hyperbolic group then the length of a shortest conjugating element for $u$ and $v$ can be bounded by a linear function of the sum of their lengths, as was proved by Lysenok. Bridson and Haefliger showed that in a hyperbolic group the conjugacy problem can be solved in polynomial time. We extend these results to relatively hyperbolic groups. In particular, we show that both the conjugacy problem and the conjugacy search problem can be solved in polynomial time in a relatively hyperbolic group, whenever the corresponding problem can be solved in polynomial time in each parabolic subgroup. We also prove that if $u$ and $v$ are two conjugate hyperbolic elements of a relatively hyperbolic group then the length of a shortest conjugating element for $u$ and $v$ is linear in terms of their lengths.
A significance statement is not available in the OpenAlex record.
A contribution statement is not available in the OpenAlex record.
Method details are not available in the OpenAlex metadata.
Findings are not separately available in the OpenAlex metadata.
Limitations are not available in the OpenAlex metadata.
Application details are not available in the OpenAlex metadata.
If $u$ and $v$ are two conjugate elements of a hyperbolic group then the length of a shortest conjugating element for $u$ and $v$ can be bounded by a linear function of the sum of their lengths, as was proved by Lysenok. Bridson and Haefliger showed that in a hyperbolic group the conjugacy problem can be solved in polynomial time. We extend these results to relatively hyperbolic groups. In particular, we show that both the conjugacy problem and the conjugacy search problem can be solved in polynomial time in a relatively hyperbolic group, whenever the corresponding problem can be solved in polynomial time in each parabolic subgroup. We also prove that if $u$ and $v$ are two conjugate hyperbolic elements of a relatively hyperbolic group then the length of a shortest conjugating element for $u$ and $v$ is linear in terms of their lengths.
Key concepts: Conjugacy class, Conjugacy problem, Mathematics, Relatively hyperbolic group, Hyperbolic group, Element (criminal law), Polynomial, Group (periodic table)