This seminar is organized by the Applied Algebra Group at TU Berlin. Anyone interested is welcome to join us. We meet roughly every second week. A detailed schedule can be seen below and will be updated throughout the semester.
Upcoming Talks
November 12, 2025 14:00 MA 650: Kevin Li (FU Berlin)
Title: On higher coherence of RAAGs
Abstract: A group is called coherent if every finitely generated subgroup is
finitely presented. It is a classical result of Droms that a RAAG is coherent
if and only if the defining graph is chordal. I will explain its proof and our
attempt to generalise it to higher coherence. Ongoing joint work with Luis
Jorge Sánchez Saldaña.
Past Talks
October 29, 2025 14:30 MA 650: Mireille Soergel (TUB)
Title: Dual Artin groups
Abstract: In 1998 when considering a new approach to the word and conjugacy problem in Braid groups, Birman-Ko-Lee introduce a new presentation for the braid group. This is now referred to as the dual presentation. Such dual presentations can be defined for all Artin groups. I will introduce standard and dual Artin groups and talk about some open conjectures.
October 29, 2025 13:45 MA 366: Tamara Imanuel
Title: Das Konjugationsproblem in RAAGs: Theorie und Algorithmus
October 22, 2025 14:30 MA 650: Sobhi Massalha (TUB)
Title: Sentences over Random Groups
Abstract: Around 2013, a natural conjecture by Julia Knight anticipated
that given a first order sentence, its truth value over a random group in
the few relators model, is equivalent to its truth value over non-abelian
free groups.
Our work extends the framework of this conjecture to random groups in the
Gromov Density Model, at optimal density d<1/2.
We prove the conjecture for sentences that belong to the Boolean algebra
of universal sentences, as well as for sentences of minimal rank with
arbitrary number of quantifiers, for random groups of density d<1/2.
In this talk, we will present our results and, as time permits, outline
the key strategies and ideas involved in the proofs.
October 8, 2025 10:45 MA 366: Alex Levine (University of East Anglia)
Title: The Diophantine problem in Thompson's group F
Abstract: We discuss equations in groups, and when there exists an algorithm that can decide if a given system of equations admits a solution. We mention some recent work on Thompson's groups F and T. Based on joint work with Luna Elliott.
October 8, 2025 10:00 MA 366: Nico Waldau (TU Berlin)
Title: Tits-Alternative für hyperbolische Gruppen