{ "id": "1709.01227", "version": "v1", "published": "2017-09-05T03:50:10.000Z", "updated": "2017-09-05T03:50:10.000Z", "title": "Electrical networks and hyperplane arrangements", "authors": [ "Bob Lutz" ], "comment": "19 pages, 4 figures", "categories": [ "math.CO" ], "abstract": "This paper connects the theory of hyperplane arrangements to the theory of linear resistor networks with fixed boundary voltages. Given a graph $G$, a set $\\partial V\\subsetneq V$, and a function $u:\\partial V\\to\\mathbb{R}$, our main object of study is the arrangement $\\mathcal{A}_{G,u}$ obtained from the real graphic arrangement $\\mathcal{A}_G$ by fixing the coordinate $x_j$ to $u(j)$ for all $j\\in\\partial V$. First, fixed-energy harmonic functions in the sense of Abrams and Kenyon are shown to be critical points of master functions in the sense of Varchenko. Second, the basic graph-theoretic descriptions of $\\mathcal{A}_G$ are generalized to $\\mathcal{A}_{G,u}$. It is also proven that the arrangements $\\mathcal{A}_{G,u}$ are equivalent to the $\\psi$-graphical arrangements introduced recently by Stanley.", "revisions": [ { "version": "v1", "updated": "2017-09-05T03:50:10.000Z" } ], "analyses": { "subjects": [ "52C35", "34B45", "05C15" ], "keywords": [ "hyperplane arrangements", "electrical networks", "real graphic arrangement", "basic graph-theoretic descriptions", "linear resistor networks" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }