On the local constancy of regularized superdeterminants along special families of differential operators
Michele Schiavina, Thomas Stucker
TL;DR
The paper develops a unified framework for local constancy of regularized superdeterminants along smooth families of general codifferentials on a twisted de Rham complex. By introducing inner variations of codifferentials $\delta_\tau$ and the associated characteristic operators $D_\tau=[\delta_\tau,d_\nabla]$, the authors derive a general invariance result for the flat determinant $\mathrm{sdet}^\flat(D_\tau|_{L_\tau})$ under suitable analytic and wavefront assumptions. Special cases recover the classical invariance of analytic torsion under metric variation and, for regular contact Anosov flows, the local constancy of the value at zero of the Ruelle zeta function, linking topological and dynamical invariants through a BV-inspired gauge-fixing interpretation. The results provide a coherent method to understand Fried-type conjectures within a broader algebraic-analytic setting, and they offer a pathway to reformulate Fried's conjecture via families of codifferentials and their gauge-fixing data.
Abstract
We consider the flat-regularized determinant of families of operators of the form $D_τ=[δ_τ,d_\nabla]$, where $τ\toδ_τ$ are families of degree $-1$ maps in the twisted de Rham complex $\left(Ω^\bullet(M,E),d_\nabla\right)$ generalizing the (twisted) Hodge codifferential. We show that under suitable assumptions, both geometrical and analytical in nature, the flat-regularized determinant of $D_τ$, restricted to the subspace $\mathrm{im}(δ_τ)$, is constant in $τ$. The general result we present implies both local constancy of the Ray--Singer torsion and of the value at zero of the Ruelle zeta function for a contact Anosov flow, upon choosing $δ_τ= δ_{g_τ}$, the Hodge codifferential for a family of metrics, and $δ_τ=ι_{X_τ}$, the contraction along a family of (regular, contact) Anosov vector fields, respectively.
