A top-down approach to algebraic renormalization in regularity structures based on multi-indices

Y Bruned, P Linares - Archive for Rational Mechanics and Analysis, 2024 - Springer
We provide an algebraic framework to describe renormalization in regularity structures
based on multi-indices for a large class of semi-linear stochastic PDEs. This framework is …

The structure group for quasi-linear equations via universal enveloping algebras

P Linares, F Otto, M Tempelmayr - Communications of the American …, 2023 - ams.org
We replace trees by multi-indices as an index set of the abstract model space to tackle quasi-
linear singular stochastic partial differential equations. We show that this approach is …

Post-Lie algebras in regularity structures

Y Bruned, F Katsetsiadis - Forum of Mathematics, Sigma, 2023 - cambridge.org
In this work, we construct the deformed Butcher-Connes-Kreimer Hopf algebra coming from
the theory of Regularity Structures as the universal envelope of a post-Lie algebra. We show …

Insertion pre-Lie products and translation of rough paths based on multi-indices

P Linares - arXiv preprint arXiv:2307.06769, 2023 - arxiv.org
We use the diagram-free approach to regularity structures introduced by Otto et. al. to build
rough paths based on multi-indices. We identify the analogue of the insertion pre-Lie …

Novikov algebras and multi-indices in regularity structures

Y Bruned, V Dotsenko - arXiv preprint arXiv:2311.09091, 2023 - arxiv.org
In this work, we introduce multi-Novikov algebras, a generalisation of Novikov algebras with
several binary operations indexed by a given set, and show that the multi-indices recently …

Algebraic structures on typed decorated rooted trees

L Foissy - SIGMA. Symmetry, Integrability and Geometry: Methods …, 2021 - emis.de
Typed decorated trees are used by Bruned, Hairer and Zambotti to give a description of a
renormalisation process on stochastic PDEs. We here study the algebraic structures on …

Symmetric resonance based integrators and forest formulae

YA Bronsard, Y Bruned, G Maierhofer… - arXiv preprint arXiv …, 2023 - arxiv.org
We introduce a unified framework of symmetric resonance based schemes which preserve
central symmetries of the underlying PDE. We extend the resonance decorated trees …

Low regularity integrators via decorated trees

YA Bronsard, Y Bruned, K Schratz - arXiv preprint arXiv:2202.01171, 2022 - arxiv.org
We introduce a general framework of low regularity integrators which allows us to
approximate the time dynamics of a large class of equations, including parabolic and …

Multi‐indice BB‐series

Y Bruned, K Ebrahimi‐Fard… - Journal of the London …, 2025 - Wiley Online Library
We propose a novel way to study numerical methods for ordinary differential equations in
one dimension via the notion of multi‐indice. The main idea is to replace rooted trees in …

Regularity structures for quasilinear singular SPDEs

I Bailleul, M Hoshino, S Kusuoka - Archive for Rational Mechanics and …, 2024 - Springer
We prove the well-posed character of a regularity structure formulation of the quasilinear
generalized (KPZ) equation and give an explicit form for a renormalized equation in the full …