Heat kernel estimate on weighted Riemannian manifolds under lower $N$-Ricci curvature bounds with $ε$-range and it's application
Wen-Qi Li, Zhikai Zhang
TL;DR
The paper develops a comprehensive framework for parabolic and spectral analysis on weighted Riemannian manifolds under lower $N$-Ricci curvature bounds in the $\varepsilon$-range. By combining Lu–Ohta’s volume comparison with Fujitani’s local Sobolev inequality, it obtains a local $φ$-heat kernel estimate, from which Gaussian upper and lower bounds for the $φ$-heat kernel are deduced via Davies’ estimates and Li–Yau-type inequalities. These bounds yield a suite of consequences, including an $L^{1}_{φ}$ Liouville theorem for $φ$-subharmonic functions, $L^{1}_{φ}$-uniqueness of the $φ$-heat equation, and eigenvalue estimates for the weighted Laplacian $Δ_{φ}$, alongside a Li–Yau gradient estimate under a weighted $L^{p}$-norm bound on $| abla φ|^{2}$. The results address open questions about negative-dimension regimes in $N$-Ricci curvature and unify several curvature-bound frameworks through the $ε$-range, offering new tools for analysis on smooth metric measure spaces.
Abstract
In this paper, we establish a parabolic Harnack inequality for positive solutions of the $φ$-heat equation and prove Gaussian upper and lower bounds for the $φ$-heat kernel on weighted Riemannian manifolds under lower $N$-Ricci curvature bound with $\varepsilon$-range. Building on these results, we demonstrate: The $L^1_φ$-Liouville theorem for $φ$-subharmonic functions, $L^1_φ$-uniqueness property for solutions of the $φ$-heat equation and lower bounds for eigenvalues of the weighted Laplacian $Δ_φ$. Furthermore, leveraging the Gaussian upper bound of the weighted heat kernel, we construct a Li-Yau-type gradient estimate for the positive solution of weighted heat equation under a weighted $L^p(μ)$-norm constraint on $|\nablaφ|^2$.
