Heat kernel-based p-energy norms on metric measure spaces
Jin Gao, Zhenyu Yu, Junda Zhang
TL;DR
The paper develops a unified framework for comparing heat kernel–based $p$-energies and Besov–Korevaar–Schoen energies on metric measure spaces, including fractals and fractal glue-ups. It introduces weak-monotonicity properties $(KE)_p$, $(NE)_p$, and $(VE)_p$ and proves their equivalences under two-sided heat kernel estimates, while also delivering BBM-type characterizations for $p eq 2$ and automatic monotonicity for $p=2$ in the Dirichlet-form setting. Under (UHE) and (LHE), it shows that heat-kernel energies and Besov–KS energies are equivalent, yielding BBM-type convergence and Gagliardo–Nirenberg inequalities on nested fractals and their blow-ups. The framework extends classical BBM results from smooth manifolds to fractal spaces, providing a robust bridge between probabilistic heat-kernel methods and deterministic Besov/Korevaar–Schoen approaches in fractal analysis, with explicit applications to nested fractals and fractal glue-ups.
Abstract
We investigate heat kernel-based and other $p$-energy norms (1<p<\infty) on bounded and unbounded metric measure spaces, in particular, on nested fractals and their blowups. With the weak-monotonicity properties for these norms, we generalise the celebrated Bourgain-Brezis-Mironescu (BBM) type characterization for p\neq2. When there admits a heat kernel satisfying the two-sided estimates, we establish the equivalence of various $p$-energy norms and weak-monotonicity properties, and show that these weak-monotonicity properties hold when p=2 (in the case of Dirichlet form). Our paper's key results concern the equivalence and verification of various weak-monotonicity properties on fractals. Consequently, many classical results on p-energy norms hold on nested fractals and their blowups, including the BBM type characterization and Gagliardo-Nirenberg inequality.
