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University of Illinois Urbana-Champaign

Questions around symplectic capacities

Abstract

dc:description

One major question in the study of symplectic capacities is the strong Viterbo conjecture: all normalized symplectic capacities agree on convex domains. This conjecture has spurred extensive research and numerous interesting results about this conjecture have been established. In this thesis, we contribute to this area by focusing on the comparison of symplectic capacities. We explore the interplay between symplectic and convex geometry. More specifically, we study convex bodies in \RR2n with the property that their mean width, one of the most fundamental measurements in convex geometry, cannot be decreased by the action of natural classes of symplectomorphisms. Our main finding is that toric symmetry is a preferred feature of convex bodies that are in optimal symplectic position with respect to the mean width. We then study an S1-equivariant version of Varolgunes' relative symplectic cohomology. As an application, we construct a relative version of the Gutt-Hutchings capacities and a relative version of the symplectic (co)homology capacity. We show that these relative symplectic capacities can detect the diplaceability and the heaviness of compact subsets of a symplectic manifold. We also compare the first relative Gutt-Hutchings capacity and the relative symplectic (co)homology capacity and prove that they are equal to each other under a natural convexity assumption.

Degree

thesis:*
Name thesis:degree_name
Ph.D.
Level thesis:degree_level
Dissertation
Discipline thesis:degree_discipline
Mathematics
Grantor
University of Illinois Urbana-Champaign
Year dc:date
2025

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Ahn, Jonghyeon
Contributors dc:contributor
  • Kerman, Ely
  • Pascaleff, James
  • Fernandes, Rui
  • Hind, Richard

Subjects

dc:subject × 1

Rights

dc:rights
Statement dc:rights
  • Copyright 2025 Jonghyeon Ahn
Language dc:language
en, eng

Identifiers

dc:identifier.*
Handle dc:identifier
https://hdl.handle.net/2142/129426

Chain of custody

source
Harvested from
University of Illinois - Urbana-Champaign
Base URL
www.ideals.illinois.edu/oai-pmh
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Ahn, Jonghyeon. Questions around symplectic capacities. Dissertation thesis, University of Illinois Urbana-Champaign, 2025. https://hdl.handle.net/2142/129426