Construction of Exotic 4-Manifolds Using Finite Order Cyclic Group Actions

Series
Geometry Topology Seminar
Time
Monday, March 2, 2026 - 2:00pm for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Nur Saglam – University of Georgia – nurmath7@uga.eduhttps://sites.google.com/view/nurmath7
Organizer
Neda Bagherifard

In this talk, we will discuss the construction of exotic 4-manifolds using Lefschetz fibrations over S^2, which are obtained by finite order cyclic group actions on Σg. We will first apply various cyclic group actions on Σg for g>0, and then extend it diagonally to the product manifolds ΣgxΣg. These will give singular manifolds with cyclic quotient singularities. Then, by resolving the singularities, we will obtain families of Lefschetz fibrations over S^2. Following the resolution process, we will determine the configurations of the singular fibers and the monodromy of the total space. In some cases, deformations of the Lefschetz fibrations give rise to nice applications using the rational blow-down operation, which provides exotic examples. This is a joint work with A. Akhmedov and M. Bhupal.