Speaker: Rhiannon Dougall
Title:
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Speaker: Susanna Terron
Title: Thompson representatives and connected sum
Abstract: In 2017 Vaughan Jones introduced a construction associating links to elements of Thompson’s group F and its generalisation F3. He then proved that all links can be obtained in such a way, opening the way to new possible connections between these objects.
In this talk I will present Jones’ construction and extend it to obtain a surjective map into the set of pointed links. I’ll then define a new algebraic structure by endowing F3 with a monoid operation, which turns our map into a surjective monoid homomorphism, with image the monoid of pointed links with operation connected sum. As a consequence, we obtain a standard form for connected sum representatives, which can then be extended to obtain representatives for a certain family of links that we will refer to as tree links.
This is based on the following paper: https://arxiv.org/abs/2511.21259
Speaker: Giovanni Forni
Title: Periodic orbits and weak chaos in polygons
Abstract: We will survey results on the dynamics in billiards in polygons, including a recent result on existence of periodic orbits and joint work with Francisco Arana-Herrera and Jon Chaika on the weak mixing property.
