{ "id": "1310.8563", "version": "v4", "published": "2013-10-31T15:55:45.000Z", "updated": "2013-12-15T14:36:04.000Z", "title": "The images of non-commutative polynomials evaluated on $2\\times 2$ matrices over an arbitrary field", "authors": [ "Sergey Malev" ], "categories": [ "math.AG" ], "abstract": "Let $p$ be a multilinear polynomial in several non-commuting variables with coefficients in an arbitrary field $K$. Kaplansky conjectured that for any $n$, the image of $p$ evaluated on the set $M_n(K)$ of $n$ by $n$ matrices is either zero, or the set of scalar matrices, or the set $sl_n(K)$ of matrices of trace $0$, or all of $M_n(K)$. This conjecture was proved for $n=2$ when $K$ is closed under quadratic extensions. In this paper the conjecture is verified for $K=\\mathbb{R}$ and $n=2$, also for semi-homogeneous polynomials $p$, with a partial solution for an arbitrary field $K$.", "revisions": [ { "version": "v4", "updated": "2013-12-15T14:36:04.000Z" } ], "analyses": { "keywords": [ "arbitrary field", "non-commutative polynomials", "conjecture", "multilinear polynomial", "scalar matrices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1310.8563M" } } }