SMS scnews item created by Hannah Bryant at Tue 14 Sep 2021 1514
Type: Seminar
Modified: Tue 14 Sep 2021 1514
Distribution: World
Expiry: 5 Oct 2021
Calendar1: 5 Oct 2021 1600-1730
CalLoc1: Online via Zoom
Auth: hannahb@10.48.28.36 (hbry8683) in SMS-SAML

# SMRI Algebra and Geometry Online: Gardam -- Solving semidecidable problems in group theory

SMRI Algebra and Geometry Online
’Solving semidecidable problems in group theory’
Giles Gardam (University of Muenster)

Tuesday October 5th, 4:00pm-5:30pm (AEDT)
Register:
https://uni-sydney.zoom.us/meeting/register/tZAvduysqjkiG9SObYuyc-VEMPyPVTQkbQ0W

Abstract: Group theory is littered with undecidable problems. A classic example is
the word problem: there are groups for which there exists no algorithm that can
decide if a product of generators represents the trivial element or not. Many
problems (the word problem included) are at least semidecidable, meaning that there
is a correct algorithm guaranteed to terminate if the answer is "yes", but with no
guarantee on how long one has to wait. I will discuss strategies to try and tackle
various semidecidable problems computationally with the key example being the
discovery of a counterexample to the Kaplansky unit conjecture.

Biography: Giles Gardam is a research associate at the University of MÃ¼nster working
in geometric group theory. He studied mathematics and computer science at the
University of Sydney, receiving his Bachelor’s degree in 2012, and completed his
doctorate at Oxford in 2017. He was then a postdoc at the Technion before starting
at Muenster in 2019.

Note: These seminars will be recorded, including participant questions (participants