A semigroup approach to the reconstruction theorem and the multilevel Schauder estimate for singular modelled distributions
Masato Hoshino, Ryoji Takano
TL;DR
The paper develops a semigroup-based approach to singular modelled distributions within Hairer’s regularity-structure framework, proving reconstruction and multilevel Schauder estimates for the singular setting. By defining Besov norms via a G-type semigroup {Q_t} and incorporating temporal weights, it extends the analytic core to regions with boundary/boundary-like singularities and non-translation-invariant operators. The authors provide an alternative, semigroup-driven derivation of reconstruction and MSE with global bounds, and demonstrate a locally well-posed PAM theory in this context, including a spacetime renormalization that yields a convergent renormalized solution for a PAM with spatially varying diffusion. These results enable local-in-time analysis of subcritical singular SPDEs with boundaries or nonuniform coefficients and establish convergence of mollified models to renormalized limits, broadening applicability to non-translation-invariant problems in stochastic PDEs.
Abstract
We extend the semigroup approach used in [23,21] to provide alternative proofs of the reconstruction theorem and the multilevel Schauder estimate for singular modelled distributions. As an application of them, we construct the local-in-time solution of the two dimensional parabolic Anderson model with a non-translation invariant differential operator.
