4 papers
Legendrian and Lagrangian higher torsion
Daniel Alvarez Gavela, Kiyoshi Igusa, Michael Sullivan
Let be a closed manifold. We introduce a family of Legendrian isotopy invariants for Legendrians in , which we collectively call Legendrian higher torsion. Given a choice…
Pseudo-torsion classes
Kiyoshi Igusa, Ray Maresca
For a finite dimensional algebra , we consider a torsion class in -, which is not necessarily finitely generated. We construct a wall-and-chamber structure for …
Derived delooping levels and finitistic dimension
Ruoyu Guo, Kiyoshi Igusa
In this paper, we develop new ideas regarding the finitistic dimension conjecture, or the findim conjecture for short. Specifically, we improve upon the delooping level by introduc…
Bijection between positive clusters and projectively signed exceptional sequences
Shujian Chen, Kiyoshi Igusa
In 2017, Igusa and Todorov gave a bijection between signed exceptional sequences and ordered partial clusters. In this paper, we show that every term in an exceptional sequence is…