Kinetic Wedge Layers and Diffusive Limit of Neutron Transport in Polygonal Domains
Abstract
We study the diffusive limit of the steady neutron transport equation with velocity-dependent in-flow boundary data in polygonal domains. On a bounded convex polygon, we construct an approximation by the interior solution, flat side layers, and wedge layers, and prove an algebraic error estimate in L∞. We also give a complete formulation and well-posedness theory for the kinetic wedge layer, including its algebraic decay. The proof combines a characteristic stability estimate, a weighted Mellin mapping theorem, a two-depth construction and matching scheme, and a shifted superharmonic barrier for the wedge corrector. We also prove the L2 diffusive limit at rate O(ε1/2) on general bounded simple polygons, including those with reentrant vertices.
Related
- On convex envelopes of bilinear terms over polygonal domains
- Identification of generic polygonal domains by integral-geometric invariants
- Maximal Lp-Lq regularity of finite element methods for stochastic parabolic equations in polygonal domains
- On the diffusive-mean field limit of a kinetic weakly interacting particle system
- Diffusive-dispersive traveling waves and kinetic relations. Generic flux with multiple inflection points
BibTeX
@misc{ouyang2026kinetic,
title = {{Kinetic Wedge Layers and Diffusive Limit of Neutron Transport in Polygonal Domains}},
author = {Zhimeng Ouyang and Lei Wu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.00698},
eprint = {2609.00698},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.00698},
}
RIS
TY - UNPB
TI - Kinetic Wedge Layers and Diffusive Limit of Neutron Transport in Polygonal Domains
AU - Zhimeng Ouyang
AU - Lei Wu
PY - 2026
DA - 2026/10/03
PB - arXiv
DO - 10.48550/arxiv.2609.00698
UR - https://arxiv.org/abs/2609.00698
AB - We study the diffusive limit of the steady neutron transport equation with velocity-dependent in-flow boundary data in polygonal domains. On a bounded convex polygon, we construct an approximation by the interior solution, flat side layers, and wedge layers, and prove an algebraic error estimate in L^∞. We also give a complete formulation and well-posedness theory for the kinetic wedge layer, including its algebraic decay. The proof combines a characteristic stability estimate, a weighted Mellin mapping theorem, a two-depth construction and matching scheme, and a shifted superharmonic barrier for the wedge corrector. We also prove the L^2 diffusive limit at rate O(ε^1/2) on general bounded simple polygons, including those with reentrant vertices.
ER -