Table of Contents
Fetching ...

Almost TQFTs via colored ribbon graphs

William Davis, Olivia Dumitrescu

Abstract

In this paper, we introduce ribbon TQFTs via Edge Contraction/Construction Axioms of colored ribbon graphs as an extension of the 2D TQFT axioms for ribbon graphs formulated in arXiv:1508.05922. We investigate nearly Frobenius structures and Almost TQFTs defined in arXiv:1907.05470 together with ribbon TQFTs. We give a classification result for ribbon TQFTs that extends the one obtained for Frobenius algebras in arXiv:1508.05922. In particular, the Edge Contraction/Construction Axioms of colored ribbon graphs in this work become equivalent to the functorial Axioms of TQFTs governed by the sewing principle of Atiyah and Segal discussed in arXiv:2510.03128 and arXiv:1907.05470. As an application, we obtain that the recursion of generalized Catalan numbers can be twisted by Almost TQFT for co-unital nearly Frobenius algebra.

Almost TQFTs via colored ribbon graphs

Abstract

In this paper, we introduce ribbon TQFTs via Edge Contraction/Construction Axioms of colored ribbon graphs as an extension of the 2D TQFT axioms for ribbon graphs formulated in arXiv:1508.05922. We investigate nearly Frobenius structures and Almost TQFTs defined in arXiv:1907.05470 together with ribbon TQFTs. We give a classification result for ribbon TQFTs that extends the one obtained for Frobenius algebras in arXiv:1508.05922. In particular, the Edge Contraction/Construction Axioms of colored ribbon graphs in this work become equivalent to the functorial Axioms of TQFTs governed by the sewing principle of Atiyah and Segal discussed in arXiv:2510.03128 and arXiv:1907.05470. As an application, we obtain that the recursion of generalized Catalan numbers can be twisted by Almost TQFT for co-unital nearly Frobenius algebra.
Paper Structure (24 sections, 27 theorems, 90 equations, 28 figures)

This paper contains 24 sections, 27 theorems, 90 equations, 28 figures.

Key Result

Theorem 1.1

Let $A$ be a nearly Frobenius algebra with coproduct $\delta$ and the Euler map $\mathbf{E}$. Then the ribbon TQFT defined in def:ribbonTQFT associated to a colored cell graph $\gamma$ of type $(g,n,m)$ with $n,m\geq 1$, is independent of the graph and is given by Where $\delta^0$ is the identity map (for the case where $m=1$).

Figures (28)

  • Figure 1: Pairs of pants decomposition of Riemann surfaces leading to topological recursion
  • Figure 2: Generating set of morphisms in the category $\mathbf{2Cob}$
  • Figure 3: Commutativity and cocommutativity relations of the twist.
  • Figure 4: Relations involving sewing discs
  • Figure 5: Associativity and coassociativity relations of cobordisms.
  • ...and 23 more figures

Theorems & Definitions (81)

  • Theorem 1.1
  • Theorem 1.2
  • Theorem 1.3
  • Corollary 1.4
  • Definition 2.1
  • Remark 2.2
  • Remark 2.3
  • Theorem 2.4
  • Definition 3.1
  • Remark 3.2
  • ...and 71 more