Displaying similar documents to “Smoothing of rational m-ropes”

On the existence of curves in ℙ n with stable normal bundle

Edoardo Ballico, Luciana Ramella (1999)

Annales Polonici Mathematici

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We prove that for integers n,d,g such that n ≥ 4, g ≥ 2n and d ≥ 2g + 3n + 1, the general (smooth) curve C in ℙ n with degree d and genus g has a stable normal bundle N C .

Strata of smooth space curves having unstable normal bundle

Luciana Ramella (1999)

Bollettino dell'Unione Matematica Italiana

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Per d ≫ g , vengono trovate curve liscie in P 3 di grado d e genere g aventi fibrato normale instabile con grado di instabilità σ , per ogni 1 ≤ σ ≤ d - 4 . Inoltre per 4 ⁢ g - 2 ≤ σ ≤ d - 4 , viene trovata una famiglia di curve in P 3 di grado d e genere g avente fibrato normale instabile con grado di instabilità σ e formante uno strato dello schema di Hilbert della giusta dimensione che è 4 ⁢ d - g + 1 - 2 ⁢ σ .

Are rational curves determined by tangent vectors?

Stefan Kebekus, Sándor J. Kovács (2004)

Annales de l’institut Fourier

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Let X be a projective variety which is covered by rational curves, for instance a Fano manifold over the complex numbers. In this paper, we give sufficient conditions which guarantee that every tangent vector at a general point of X is contained in at most one rational curve of minimal degree. As an immediate application, we obtain irreducibility criteria for the space of minimal rational curves.

Threefolds with nef anticanonical bundles.

Thomas Peternell, Fernando Serrano (1998)

Collectanea Mathematica

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In this paper we study the global structure of projective threefolds X whose anticanonical bundle -KX is nef.