Speaker: Jonathan Trejos is from Colombia. He currently holds a postdoctoral position at the Southern University of Science and Technology (SUSTech) in China, under the supervision of Professor Pedro Salomão. From 2019 to 2024, He was a PhD student at IMPA, supervised by Vinicius Ramos. His research interest is in symplectic and contact topology, with particular emphasis on symplectic embeddings, four-dimensional symplectic manifolds, and embedded contact homology (ECH).

Date: December 23, 2025

Time: 14:30-15:30 pm

Location: B1044, Zhixin Building, Shandong University

Sponsor: School of Mathematics, Shandong University

Abstract:

In the study of symplectic embeddings there are two possible approaches. One is the constructive approach, in which it is explicitly shown that a symplectic manifold can be embedded into another. The other one is the obstructive approach, in which properties between the manifolds that prevent the existence of the embedding are identified. In dimension four, ECH capacities constitute a particularly interesting example in the obstructive direction. In this lecture, we will briefly describe the relationship between ECH capacities and a class of four-dimensional symplectic manifolds known as singular toric domains. In particular, we will address the ECH capacities of concave toric domains and their relationship to certain ball-packing problems. Finally, we will briefly discuss the proof of some of these relationships.

For more information, please visit:

https://view.sdu.edu.cn/info/1020/209233.htm