Topology Seminar talks at Southampton

The talks are all happening at University of Southampton (in person), on Highfield Campus (SO17 1BJ). For the building and the room, see the individual postings. Email the organiser ( d (dot) kasprowski (at) soton.ac.uk ) if you have questions.

More Pure Maths talks at Southampton: we run Pure Maths Colloquia, Pure Lunchtime Seminar, and Pure Postgraduate Seminar (link soon).

Upcoming talks

• Mon 3 Nov 2025 14:00 (in B54 / 8033 (8B)): Giovanni Italiano (Oxford): Virtual fibring of manifolds and groups
  unroll abstract

  Fibrations of hyperbolic 3-manifolds have attracted a lot of attention in the last 50 years, culminating in the Virtual Fibring Theorem of Agol in 2012, which confirmed Thurston's conjecture that all hyperbolic 3-manifolds have a finite cover that fibres over the circle. This raises the question on whether this phenomenon occurs also in higher dimensions. After a short survey about recent results, I will talk about recent progress on fibrations of Poincaré-duality groups, which is joint work with Sam Fisher and Dawid Kielak.

• Mon 10 Nov 2025 14:00 (in B54 / 8033 (8B)): Ulrich Pennig (Cardiff): TBA
  No abstract yet.
• Mon 24 Nov 2025 14:00 (in B54 / 8033 (8B)): Nansen Petrosyan (Southampton): TBA
  No abstract yet.
• Mon 8 Dec 2025 14:00 (in B54 / 8033 (8B)): Sebastian Chenery (Bristol): TBA
  No abstract yet.
• Tue 9 Dec 2025 14:00 (in B54 / 8033 (8B) (Note the unusual day)): Samik Basu (ISI Kolkata): TBA
  No abstract yet.
• Mon 2 Mar 2026 14:00 (in B54 / 8033 (8B)): Mark Hagen (Bristol): TBA
  No abstract yet.
• Mon 16 Mar 2026 14:00 (in B54 / 8033 (8B)): Daniel Marlowe (Warwick): TBA
  No abstract yet.

Recent talks

• Mon 27 Oct 2025 14:00: Lewis Stanton (Southampton): Anick's conjecture for polyhedral products
  unroll abstract

  Anick conjectured the following after localisation at any sufficiently large prime - the pointed loop space of any finite, simply connected CW complex is homotopy equivalent to a finite type product of spheres, loops on spheres, and a list of well-studied torsion spaces defined by Cohen, Moore and Neisendorfer. We study this question in the context of moment-angle complexes, a central object in toric topology which are indexed by simplicial complexes. These are a special case of a family of spaces known as polyhedral products, which unify constructions across mathematics. Recently, much work has been done to find families of simplicial complexes for which the corresponding moment-angle complex satisfies Anick's conjecture integrally. In this talk, I will survey what is known, and show that the loop space of any moment-angle complex is homotopy equivalent to a product of looped spheres after localisation away from a finite set of primes. This is then used to show Anick's conjecture holds for a much wider family of polyhedral products. This talk is based on joint work with Fedor Vylegzhanin.

• Mon 13 Oct 2025 14:00: Rudradip Biswas (Warwick): E1 rings, t-structures, and regularity
  unroll abstract

  I will start with talking about the various existing notions of regularity for E1 rings, and then move to how my work with Hongxing Chen et al (arxiv:2401.00130) introduces a notion of (categorical) regularity in the language of completions. I will talk about the motivations of this work, and the connections between our regularity and the existing notions. I will also highlight how our work is connected with solving some conjectures in algebraic geometry.

• Mon 6 Oct 2025 14:00: Sungkyung Kang (Cambridge): An exotic Dehn twist after two stabilizations
  unroll abstract

  Unlike in higher dimensions, most exotic phenomena on simply-connected 4-manifolds are unstable; they become non-exotic after finitely many stabilizations. While we now know that some of them survive one stabilization, nothing is known about their behavior when we stabilize them more than once. In this talk, we present the first example of an exotic diffeomorphism on a smooth contractible 4-manifold, given as a boundary Dehn twist along its (nontrivial) boundary, which stays exotic after two stabilizations. This is an ongoing joint work with JungHwan Park and Masaki Taniguchi.

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