Geometric invariants of TDLC completions
Ilaria Castellano (Politecnico di Torino)
- https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/mathe/veranstaltungen/wissenschaftliche_veranstaltungen/oberseminar_algebra_geometrie_topologie/termine/castellano
- Geometric invariants of TDLC completions
- 2025-11-18T16:00:00+01:00
- 2025-11-18T17:30:00+01:00
- Ilaria Castellano (Politecnico di Torino)
18.11.2025 von 16:00 bis 17:30 (Europe/Berlin / UTC100)
Let 𝛤 be a Hausdorff topological group and 𝛬 an open commensurated subgroup of 𝛤. A TDLC completion (short for totally disconnected locally compact completion) of (𝛤,𝛬) is a pair (𝐺,𝜙) where: 𝐺 is a TDLC group, 𝜙:𝛤→𝐺 is a continuous homomorphism with dense image and 𝛬=𝜙⁻¹(𝐿) for some compact open subgroup 𝐿⊆𝐺. One important example is given by Schlichting completions. Recently, Bonn and Sauer investigated how the compactness properties behave under Schlichting completion. They showed that, from this point of view, the Schlichting completion of a pair (𝛤,𝛬) acts precisely as if it were the quotient of 𝛤 by 𝛬. Motivated by this result, José Pedro Quintanilha and I set out to explore whether a similar phenomenon holds for the 𝛴-sets. In this talk, I will present the main result along with some applications (if time permits).