Displaying similar documents to “Seshadri positive curves in a smooth projective 3 -fold”

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.

Geometric genera for ample vector bundles with regular sections.

Antonio Lanteri (2000)

Revista Matemática Complutense

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Let X be a smooth complex projective variety of dimension n ≥ 3. A notion of geometric genus p(X,E) for ample vector bundles E of rank r < n on X admitting some regular sections is introduced. The following inequality holds: p(X,E) ≥ h(X). The question of characterizing equality is discussed and the answer is given for E decomposable of corank 2. Some conjectures suggested by the result are formulated.

Seshadri positive submanifolds of polarized manifolds

Lucian Bădescu, Mauro Beltrametti (2013)

Open Mathematics

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Let Y be a submanifold of dimension y of a polarized complex manifold (X, A) of dimension k ≥ 2, with 1 ≤ y ≤ k−1. We define and study two positivity conditions on Y in (X, A), called Seshadri A-bigness and (a stronger one) Seshadri A-ampleness. In this way we get a natural generalization of the theory initiated by Paoletti in [Paoletti R., Seshadri positive curves in a smooth projective 3-fold, Atti Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei (9) Mat. Appl., 1996, 6(4),...

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 .