A. Moldenhauer

activity

20152025

collaborators

5 papers

math.GR2025

Subgroups of Cyclically Amalgamated Free Products

Martin Kreuzer, Anja Moldenhauer, Gerhard Rosenberger

Given a group $G = H_{1} *_{A} H_{2}$ which is the free product of two finitely generated groups $H_{1}$ and $H_{2}$ with amalgamation over a cyclic subgroup $A$ which is malnormal in $G$ …

math.GR2025

Trace Minimization and Roots in $PSL (2, R)$

Martin Kreuzer, Anja Moldenhauer, Gerhard Rosenberger

Suppose that $A, B \in PSL (2, R)$ generate a non-elementary Fuchsian group. Let $m, n \in N_{+}$ , and let $R, S \in PSL (2, R)$ such that $R^{m} = A$ and $S…

math.GR2016

Cryptosystems Using Automorphisms of Finitely Generated Free Groups

Anja I. S. Moldenhauer, Gerhard Rosenberger

This paper introduces a newly developed private key cryptosystem and a public key cryptosystem. In the first one, each letter is encrypted with a different key. Therefore, it is a…

math.NT2015

On the generalized Hurwitz equations and the Baragar-Umeda equations

Benjamin Fine, Gabriele Kern-Isberner, Anja I. S. Moldenhauer +1

We consider the generalized Hurwitz equation $a_{1} x_{1}^{2} + \dots + a_{n} x_{n}^{2} = d x_{1} \dots x_{n} - k$ and the Baragar-Umeda equation $a x^{2} + b y^{2} + c z^{2} = d x y z + e$ for solvability in integers.

math.GR2015

Cryptographic protocols based on Nielsen transformations