{ "id": "math/0512291", "version": "v5", "published": "2005-12-13T23:00:14.000Z", "updated": "2006-01-10T06:37:36.000Z", "title": "Some bounds on convex combinations of $ω$ and $χ$ for decompositions into many parts", "authors": [ "Landon Rabern" ], "categories": [ "math.CO" ], "abstract": "A \\emph{$k$--decomposition} of the complete graph $K_n$ is a decomposition of $K_n$ into $k$ spanning subgraphs $G_1,...,G_k$. For a graph parameter $p$, let $p(k;K_n)$ denote the maximum of $\\displaystyle \\sum_{j=1}^{k} p(G_j)$ over all $k$--decompositions of $K_n$. It is known that $\\chi(k;K_n) = omega(k;K_n)$ for $k \\leq 3$ and conjectured that this equality holds for all $k$. In an attempt to get a handle on this, we study convex combinations of $\\omega$ and $\\chi$; namely, the graph parameters $A_r(G) = (1-r) \\omega(G) + r \\chi(G)$ for $0 \\leq r \\leq 1$. It is proven that $A_r(k;K_n) \\leq n + {k \\choose 2}$ for small $r$. In addition, we prove some generalizations of a theorem of Kostochka, et al. \\cite{kostochka}.", "revisions": [ { "version": "v5", "updated": "2006-01-10T06:37:36.000Z" } ], "analyses": { "keywords": [ "decomposition", "graph parameter", "study convex combinations", "complete graph", "equality holds" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math.....12291R" } } }