{ "id": "math/9607217", "version": "v1", "published": "1996-07-08T00:00:00.000Z", "updated": "1996-07-08T00:00:00.000Z", "title": "Rational curves and ampleness properties of the tangent bundle of algebraic varieties", "authors": [ "Frédéric Campana", "Thomas Peternell" ], "categories": [ "math.AG" ], "abstract": "The purpose of this paper is to translate positivity properties of the tangent bundle (and the anti-canonical bundle) of an algebraic manifold into existence and movability properties of rational curves and to investigate the impact on the global geometry of the manifold $X$. Among the results we prove are these: \\quad If $X$ is a projective manifold, and ${\\cal E} \\subset T_X$ is an ample locally free sheaf with $n-2\\ge rk {\\cal E}\\ge n$, then $X \\simeq \\EP_n$. \\quad Let $X$ be a projective manifold. If $X$ is rationally connected, then there exists a free $T_X$-ample family of (rational) curves. If $X$ admits a free $T_X$-ample family of curves, then $X$ is rationally generated.", "revisions": [ { "version": "v1", "updated": "1996-07-08T00:00:00.000Z" } ], "analyses": { "keywords": [ "rational curves", "tangent bundle", "algebraic varieties", "ampleness properties", "translate positivity properties" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1996math......7217C" } } }