A simple perturbation of Vafa-Witten equations and a transversality result
Bo Dai, Ren Guan
TL;DR
The paper studies a simple perturbation of the Vafa-Witten equations on closed 4-manifolds with $SU(2)$ or $SO(3)$ bundles. It shows that for generic perturbations $\tau$, the full-rank part of the perturbed moduli space is a smooth, oriented, zero-dimensional manifold by proving transversality of the parameterized map $F$. The key analytic step is establishing the surjectivity of $dF_{(\tau,A,B,C)}$ at zeros with $B$ of rank $3$ via an $L^2$-adjoint analysis and unique continuation, which implies transversality and enables Sard-Smale genericity. This provides a solid analytic foundation for rank-3 Vafa-Witten moduli spaces and supports potential invariants defined from the perturbed theory.
Abstract
We consider a simple perturbation of the Vafa-Witten equations, and prove that for generic perturbation parameter, the full rank part of the perturbed Vafa-Witten moduli space satisfies transversality condition, when the structure group is $SU(2)$ or $SO(3)$.
