Canonical torsion linking pairings and explicit TMF state spaces of closed 3-manifolds
Ruiliang Li
TL;DR
The paper provides a complete, computable framework for the TMF-valued GKMP state spaces of closed 3-manifolds by introducing Canon(A), a canonical, Kirby-stable invariant of the torsion linking form. It builds a realization dictionary 𝓡 from canonical tokens to TMF-modules, yielding Z_TMF(Y) ≃ 𝓡(Canon(A)) and revealing a prime-local, assembly-like structure of state spaces. The authors identify the Hopf elements ν and η in the TMF-stem as invariants arising from CP² and S²×S², and establish a rank-one time-reversal duality L(−n) ≃ L(n)ᵛ[1], giving a deep duality picture. Together, these results provide a computable, canonical, and structurally rich description of GKMP TMF-state spaces with clear connections to classical invariants and dualities, enabling practical calculations and conceptual insight into TMF TQFTs.
Abstract
We study the TMF-valued $(3+1)$-dimensional TQFT of Gukov--Krushkal--Meier--Pei and give an explicit description of the TMF-module state space assigned to a closed $3$-manifold. Our starting point is the torsion linking pairing on $H_1$, viewed as a discriminant form. We construct a canonical, computable package of invariants for torsion linking pairings (uniformly for odd and $2$-primary parts), and from it a canonical tokenization together with an explicit symmetric integral matrix representative realizing the same stable class. This yields an explicit model for the GKMP state space in terms of a rank-one TMF-module $L_b$ with a canonical degree shift determined by signature data. As applications we identify the values on $CP^2$ and, conditional on a natural functoriality/duality statement in GKMP, on $S^2\times S^2$ with the Hopf elements $\pmν$ and $η$, respectively. Finally, we establish a rank-one time-reversal duality $L_{(-n)}\simeq L_{(n)}^\vee[1]$ for all integers $n$.
