{ "id": "math/0403078", "version": "v2", "published": "2004-03-03T16:47:54.000Z", "updated": "2004-12-21T17:47:59.000Z", "title": "Iteration at the boundary of the space of rational maps", "authors": [ "Laura DeMarco" ], "comment": "25 pages", "categories": [ "math.DS", "math.CV" ], "abstract": "Let $Rat_d$ denote the space of holomorphic self-maps of ${\\bf P}^1$ of degree $d\\geq 2$, and $\\mu_f$ the measure of maximal entropy for $f\\in Rat_d$. The map of measures $f\\mapsto\\mu_f$ is known to be continuous on $Rat_d$, and it is shown here to extend continuously to the boundary of $Rat_d$ in $\\bar{Rat}_d \\simeq {\\bf P}^{2d+1}$, except along a locus $I(d)$ of codimension $d+1$. The set $I(d)$ is also the indeterminacy locus of the iterate map $f\\mapsto f^n$ for every $n\\geq 2$. The limiting measures are given explicitly, away from $I(d)$. The degenerations of rational maps are also described in terms of metrics of non-negative curvature on the Riemann sphere: the limits are polyhedral.", "revisions": [ { "version": "v2", "updated": "2004-12-21T17:47:59.000Z" } ], "analyses": { "keywords": [ "rational maps", "riemann sphere", "holomorphic self-maps", "indeterminacy locus", "iterate map" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......3078D" } } }