The seminar "Interactions" joins the teams of two universities: that of Cologne, and that of Marburg, therefore the name "ColMar** Interactions". The goal is to explain some very recent developments in the field of equivariant topology and equivariant symplectic geometry.

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The organisers are:

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Oliver Goertsches (goertsch@mathematik.uni-marburg.de)

Panagiotis Konstantis (pako@mathematik.uni-marburg.de)

myself (sabatini@math.uni-koeln.de)

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The talks will be on Friday from 2:30 to 3:30 PM Cologne time (CEST). See below for the list of the available Fridays.

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Every talk will be streamed on Zoom and, if the speaker is "local", the talks will be held in person.

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Talks in the winter semester 2023/2024:

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27.10.23: Nicholas Lindsay (University of Cologne), Exotic almost complex circle actions on 6-manifolds

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03.11.23: Leonor Godinho (Instituto Superior Tecnico, Lisbon), On a symplectic generalization of a Hirzebruch problem

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17.11.23: Taras Panov (Moscow State University), Holomorphic foliations on complex manifolds with torus actions

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24.11.23: Liat Kessler (University of Haifa), Extending cyclic actions to circle actions, using combinatorial, holomorphic and number-theoretic methods.

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01.12.23: Ping Li (Fudan University, Shanghai), The complex genera, symmetric functions and multiple zeta values

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15.12.23: Ana Cannas da Silva (ETH Zurich), Toric Lagrangians

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12.01.24: Yunhyung Cho (Sungkyunkwan University), Maximal tori in the Hamiltonian diffeomorphism groups and their mutations

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19.01.24: Rebecca Goldin (George Mason University), On positivity for flag manifolds and Hessenberg spaces

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Talks in the summer semester 2023:

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19.05.23: Mikiya Masuda (Osaka City University), Topology of regular semisimple Hessenberg varieties and related topics

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09.06.23: Daniele Sepe (Universidade Federal Fluminense), On some integrable systems on complexity one spaces​

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14.07.23: Seonjeong Park (Jeonju University), Classification of toric Schubert varieties

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Talks in the winter semester 2022/2023:

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11.11.22: Jeffrey Carlson (Imperial College London), The topology of Gelfand–Zeitlin fibers

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25.11.22: Maarten Mol (MPI Bonn), Stratification of the transverse momentum map

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02.12.22: Donghoon Jang (Pusan National University), Almost complex torus manifolds - graphs, Hirzebruch genera, and a problem of Petrie type

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13.01.22: Masoumeh Zarei (U. Münster), Alexandrov spaces, symmetry and positive curvature

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20.01.23: Yichen Liu (University of Illinois Urbana-Champaign), Extending complexity-1 spaces to toric manifolds

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27.01.23: Matthias Franz (University of Western Ontario), The cohomology rings of real toric spaces and smooth real toric 
varieties

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03.02.23: Shintaro Kuroki (Okayama University of Science), TBA

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* In the summer semester 2022 the seminar was organised by the University of Marburg only. Here you can find the link to the seminar website for this semester:

 

https://www.mathematik.uni-marburg.de/~pako/ColMar2022.html

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* Previous talks in the winter semester 2021/2022:

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21.10.21, 14:30-16:00: Nicholas Lindsay (U. of Cologne), "Hamiltonian S^1-actions on complete intersections"

17.11.21, 12:30-14:00: Anton Ayzenberg (HSE University), "Face posets of equivariantly formal torus actions"

09.12.21, 14:30-16:00: Chris McDaniel (Endicott College), "A GKM Description for the Equivariant Coinvariant Ring of a Pseudo Reflection Group"

16.12.21, 14:30-16:00: Lisa Jeffrey (U. of Toronto), "Poisson maps between character varieties: gluing and capping"

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* Link to talks in the academic year 2020/2021:

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https://www.silvia-sabatini.com/seminar-interactions-ws2021

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** It is also worth noticing that in Italian "colmare" means "to bridge", and we like bridges, because they allow interactions...

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