{ "id": "2006.16072", "version": "v1", "published": "2020-06-29T14:25:07.000Z", "updated": "2020-06-29T14:25:07.000Z", "title": "Spatial graph as connected sum of a planar graph and a braid", "authors": [ "Valeriy G. Bardakov", "Akio Kawauchi" ], "comment": "14 pages, 14 figures", "categories": [ "math.GT", "math.GR" ], "abstract": "In this paper we show that every finite spatial graph is a connected sum of a planar graph, which is a forest, i.e. disjoint union of finite number of trees and a tangle. As a consequence we get that any finite spatial graph is a connected sum of a planar graph and a braid. Using these decompositions it is not difficult to find a set of generators and defining relations for the fundamental group of compliment of a spatial graph in 3-space $\\mathbb{R}^3$.", "revisions": [ { "version": "v1", "updated": "2020-06-29T14:25:07.000Z" } ], "analyses": { "subjects": [ "57M07", "57M25" ], "keywords": [ "planar graph", "connected sum", "finite spatial graph", "disjoint union", "finite number" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }