Geb. 20.30, SR. 2.058

22.01.2026

Gangotryi Sorcar  (Krea University in Sri City)

15:45

Abstract: Flag-no-square (fns) triangulations arise naturally in geometric group theory through their connection to non-positively curved cube complexes. While every manifold of dimension at most three admits an fns triangulation and no manifold of dimension at least five does, the four-dimensional case is especially subtle. In joint work with Eran Nevo and Daniel Kalmanovich, we construct new examples of closed 4-manifolds admitting flag-no-square triangulations. In particular, we show that for every sufficiently large even integer 2k, there exists an fns 4-manifold with Euler characteristic 2k, and we give bounds on the number of combinatorially distinct fns triangulations such manifolds can support.