{ "id": "1512.07944", "version": "v1", "published": "2015-12-25T02:25:29.000Z", "updated": "2015-12-25T02:25:29.000Z", "title": "Graphs and Metric 2-step Nilpotent Lie Algebras", "authors": [ "Rachelle DeCoste", "Lisa DeMeyer", "Meera Mainkar" ], "categories": [ "math.DG" ], "abstract": "Dani and Mainkar introduced a method for constructing a 2-step nilpotent Lie algebra $\\mathfrak{n}_G$ from a simple directed graph $G$ in 2005. There is a natural inner product on $\\mathfrak{n}_G$ arising from the construction. We study geometric properties of the associated simply connected 2-step nilpotent Lie group $N$ with Lie algebra $\\mathfrak{n}_G$. We classify singularity properties of the Lie algebra $\\mathfrak{n}_G$ in terms of the graph $G$. A comprehensive description is given of graphs $G$ which give rise to Heisenberg-like Lie algebras. Conditions are given on the graph $G$ and on a lattice $\\Gamma \\subseteq N$ for which the quotient $\\Gamma \\backslash N$, a compact nilmanifold, has a dense set of smoothly closed geodesics.", "revisions": [ { "version": "v1", "updated": "2015-12-25T02:25:29.000Z" } ], "analyses": { "subjects": [ "22E25", "53C30", "53C22" ], "keywords": [ "nilpotent lie algebra", "nilpotent lie group", "natural inner product", "study geometric properties", "simple directed graph" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }