2024/06/20 by Nickolas Andres Castro, Castro, Nickolas Andres, Jason Joseph +3
Decision Sciences · #57M05 #57M50 #Algebraic Topology (math.AT) #FOS: Mathematics #Geometric Topology (math.GT) #M7K40 #Optimal Experimental Design Methods
paper · pdf · doi:10.48550/arxiv.2406.14530
openalex publication_date 2024/06/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Trisections of closed 4-manifolds, first defined and studied by Gay and Kirby, have proved to be a useful tool in the systematic analysis of 4-manifolds via handlebodies. Subsequent work of Abrams, Gay, and Kirby established a connection with the algebraic notion of a group trisection, which strikingly defines a one-to-one correspondence. We generalize the notion of a group trisection to the non-closed case by defining and studying relative group trisections. We establish an analogous one-to-one correspondence between relative trisections and relative group trisections up to equivalence. The key lemma in the construction may be of independent interest, as it generalizes the classical fact that there is a unique handlebody extension of a surface realizing a given surjection. Moreover, we establish a functorial relationship between relative trisections of manifolds and groups, extending work of Klug in the closed case.