A symmetric monoidal Frohman-Nicas TQFT for sutured manifolds

Abstract: By analyzing the decategorification of bordered sutured Heegaard Floer homology, we reinterpret and generalize the classical Frohman-Nicas TQFT for the Alexander polynomial in the setting of 3d sutured cobordisms between sutured surfaces. In this setting, the Frohman-Nicas TQFT maps for arbitrary cobordisms between surfaces, with no connectivity restrictions, get interpreted as part of an honest symmetric monoidal functor (under disjoint union) with no half-projectivity zeroes. We also relate the decategorified bordered sutured theory with $\mathrm{Spin}^c$ structures to a sutured version of Florens-Massuyeau's $G$-analogue of the Frohman-Nicas TQFT.