4-dimensional Skein modules, Handle attachments, and Tangles
Gage Martin, Mary Stelow, Mira Wattal
TL;DR
We address the problem of describing how skein lasagna modules $S^\star(X; L)$ behave under fundamental 4-manifold handle attachments by establishing a general gluing formula and then deducing explicit $1$-, $2$-, and $3$-handle attachment rules for arbitrary functorial link theories $H^\star$. The core method is a gluing theorem expressing $S^\star(X; T_1\cup_P T_2) \cong S^\star(X_1; Y; T_1) \otimes_{S^\star(Y; P)} S^\star(X_2; Y; T_2)$, with a constructive map built from fillings and an inverse obtained by cutting along the gluing interface. The main contributions are: (i) a unified framework for $1$-, $2$-, $3$-handle formulae applicable to any $H^\star$ satisfying minimal monoidal and cobordism-extension properties; (ii) explicit reductions to known formulas recovering Manolescu-Neithalath, Ren-Willis, Chen, and related results in $H^\star$, KhR$_n$, Kh, and Lee theories; (iii) explicit algebra/module constructions controlling gluing and actions. This approach advances 4-manifold studies by providing a versatile toolkit for cutting-and-pasting skein-theoretic invariants and clarifies the structural reasons behind previously observed similarities among different 2-handle formulae.
Abstract
Skein lasagna modules are a recent tool developed for the study of 4-manifolds. We provide general formula for 1-, 2-, and 3-handle attachments for skein modules defined with any functorial link theory in $S^3 \times I$ generalizing existing formula of Chen, Manolescu-Neithalath, Manolescu-Walker-Wedrich, and Ren-Willis. These formula are derived from a complete description of the gluing homomorphism on skein modules. For this description, we introduce a variation of these skein modules in the presence of distinguished 3-manifolds in the boundary. A similar construction was recently introduced independently by Blackwell-Krushkal-Luo.
