For a while now, Peter Mayr and I have been looking at properties of direct and subdirect products in algebra, often motivated by some well known or particularly nice results from combinatorial group theory. The topics include finite generation, finite presentability, residual finiteness, infinite subdirect powers, etc. A fairly rich landscape has emerged over the years. Perhaps unsurprisingly the most general results can be obtained in the context of congruence permutable or modular varieties. This then leaves semigroups outside, and I have been working on such questions in parallel with some of my PhD students. In this talk I will try to sketch this landscape, not so much by means of a systematics introduction, but a few selected strands, results and comparisons.

Direct and subdirect products in combinatorial algebra, groups and semigroups Sponsored by the Meyer Fund

Tue, Apr. 5 3pm (MATH 350)

Topology

Marvin Qi (CU Boulder)

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This talk should cover symmetries of MTCs and the process of gauging these symmetries to create new MTCs. The emerging notion of G-crossed braided fusion categories should also be noted.

The talks are in-person with a computer pointed at the blackboard zoom option: https://cuboulder.zoom.us/j/98979344859?pwd=K3ZrTWt4Wkk1cllOQ1pkcW4vZ1FCZz09 Meeting ID: 989 7934 4859 Passcode: 787231