{ "id": "2011.07535", "version": "v1", "published": "2020-11-15T14:03:59.000Z", "updated": "2020-11-15T14:03:59.000Z", "title": "The heat equation with order-respecting absorption and particle systems with topological interaction", "authors": [ "Rami Atar" ], "categories": [ "math.PR" ], "abstract": "A PDE formulation is proposed, referred to as a heat equation with order-respecting absorption, aimed at characterizing hydrodynamic limits of a class of particle systems on the line with topological interaction that have so far been described by free boundary problems. It consists of the heat equation with measure-valued injection and absorption terms, where the absorption measure respects the usual order on $\\R$ in the sense that, for all $r\\in\\R$, it charges $(-\\iy,r)$ only at times when the solution vanishes on $(r,\\iy)$. The formulation is used to obtain new hydrodynamic limit results for two models. One is a variant of the main model studied by Carinci, De Masi, Giardin\\`a and Presutti \\cite{CDGPbook} where Brownian particles undergo injection according to a general injection measure, and removal that is restricted to the rightmost particle of the configuration. This partially addresses a conjecture of \\cite{CDGPbook}. Next a Brownian particle system is considered where the $Q$-quantile member of the population is removed until extinction, where $Q$ is a given $[0,1]$-valued continuous function of time. Here, unlike in earlier work on the subject, the removal mechanism acts on particles that are `at the boundary' but are not rightmost or leftmost. Finally, further potential uses of order-respecting absorption are mentioned.", "revisions": [ { "version": "v1", "updated": "2020-11-15T14:03:59.000Z" } ], "analyses": { "keywords": [ "heat equation", "order-respecting absorption", "topological interaction", "brownian particles undergo injection", "free boundary problems" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }