Seminar
Logic Seminar
The Logic seminar is held on Wednesdays, usually at 12-14. If not separately specified, the talks always start at a quarter past.
We occasionally have online talks - the permanent Zoom room for the seminar is: https://helsinki.zoom.us/j/62891400777?pwd=UldCeThTaTJVQjUzUFo4S2ErcndNQT09 (Meeting ID: 628 9140 0777, Passcode: 164195)
The seminar is led by prof. Juha Kontinen and Åsa Hirvonen.
Schedule of the fall term 2026
Extra seminar: Wed 12.8.2026 12-14, C124
Ulla Karhumäki: Permutation groups definable in tame theories
Abstract: I will give an overview about results on (definably) primitive permutation groups in model theory. In particular, I will present the classification of pseudo-finite primitive permutation groups of finite SU-rank. If time permits I will also discuss a related result on generically (n+2)-transitive permutation groups definable in a model of ACF. This is joint work with Nicholas Ramsey.
Wed 2.9.2026 12-14, C124
Anssi Yli-Jyrä: Graph-encoding languages as a special case of 2-stack visibly pushdown languages
Abstract: Visibly pushdown languages (VPL) are known for their attractive closure and decidability properties, unlike their multi-stack generalization, which has already undecidable emptiness. This presentation views an existing sequential encoding (Yli-Jyrä 2019, FSMNLP) for ordered graphs as a two-stack visibly pushdown language (2MVPL). The emergent special structure of graph-encoding languages motivates a decomposition of the pertinent computations and a new model, recurrent incidence automaton, and their languages (RIL). The closure and decision properties of this model and its three restrictions (DRIL, UARIL, GRIL) are studied in relation to VPLs and 2MVPLs.
Tue 8.9.2026 14-16, C323 (Note the unusual day, time, and place)
Timon Barlag: TBA
Wed 16.9.2026 12-14, C124
Tianwei Zhang: TBA
Wed 23.9.2026 12-14, C124
Wed 30.9.2026 12-14, C124
Minna Hirvonen: TBA
Wed 7.10.2026 12-14, C124
Juan Pablo Quijano: TBA
Wed 14.10.2026 12-14, C124
Wed 21.10.2026 12-14, C124
Exam week, no seminar
Wed 28.10.2026 12-14, C124
Wed 4.11.2026 12-14, C124
Miguel Moreno: TBA
Wed 11.11.2026 12-14, C124
Jean-Charles Belouard: TBA
Wed 18.11.2026 12-14, C124
Wed 25.11.2026 12-14, C124
Wed 2.12.2026 12-14, C124
Wed 9.12.2026 12-14, C124
Wed 16.12.2026 12-14, C124
Exam week, no seminar