{ "id": "1603.07619", "version": "v1", "published": "2016-03-23T03:57:08.000Z", "updated": "2016-03-23T03:57:08.000Z", "title": "The number of direct-sum decompositions of a finite vector space", "authors": [ "David Ellerman" ], "categories": [ "math.CO" ], "abstract": "The theory of q-analogs develops many combinatorial formulas for finite vector spaces over a finite field with q elements--all in analogy with formulas for finite sets (which are the special case of q=1). A direct-sum decomposition of a finite vector space is the vector space analogue of a set partition. This paper develops the formulas for the number of direct-sum decompositions that are the q-analogs of the formulas for: (1) the number of set partitions with a given number partition signature; (2) the number of set partitions of an n-element set with m blocks (the Stirling numbers of the second kind); and (3) for the total number of set partitions of an n-element set (the Bell numbers).", "revisions": [ { "version": "v1", "updated": "2016-03-23T03:57:08.000Z" } ], "analyses": { "subjects": [ "05A18" ], "keywords": [ "finite vector space", "direct-sum decomposition", "set partition", "n-element set", "vector space analogue" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160307619E" } } }