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Related papers: Notes on Fano varieties of complete intersections

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The purpose of this note is to show that the subvarieties of small degree inside a general hypersurface of large degree come from intersecting with linear spaces or other varieties.

Algebraic Geometry · Mathematics 2025-10-15 Nathan Chen , David Yang

In this paper we address Fano foliations on complex projective varieties. These are foliations whose anti-canonical class is ample. We focus our attention on a special class of Fano foliations, namely del Pezzo foliations on complex…

Algebraic Geometry · Mathematics 2012-01-27 Carolina Araujo , Stéphane Druel

For Fano varieties of various singularities such as canonical and terminal, we construct examples with large Fano index. By low-dimensional evidence, we conjecture that our examples have the largest Fano index for all dimensions.

Algebraic Geometry · Mathematics 2023-08-15 Chengxi Wang

We study the geometry of fanning curves in the Grassmann manifold of n-dimensional subspaces of $\mathbb{R}^{kn}$; we construct a complete system of invariants which solve the congruence problem. The geometry of the invariants themselves…

Differential Geometry · Mathematics 2016-10-25 Carlos E. Durán , Cíntia R. de A. Peixoto

It is proven that any structure of a fibre space into varieties of Kodaira dimension zero on a generic Fano complete intersection of index one and dimension $M$ in ${\mathbb P}^{M+k}$ for $M\geq 2k+1$ is a pencil of hyperplane sections. We…

Algebraic Geometry · Mathematics 2011-10-11 Aleksandr Pukhlikov

We prove the birational rigidity of Fano complete intersections of index 1 with a singular point of high multiplicity, which can be close to the degree of the variety. In particular, the groups of birational and biregular automorphisms of…

Algebraic Geometry · Mathematics 2017-11-07 Aleksandr V. Pukhlikov

Let X be a subvariety of $P^n$ defined by equations of degrees $ d =(d_1,...,d_s)$, over an algebraically closed field k of any characteristic. We study properties of the Fano scheme $F_r(X)$ that parametrizes linear subspaces of dimension…

alg-geom · Mathematics 2008-02-03 O. Debarre , L. Manivel

On a general hypersurface of degree $d\leq n$ in $\mathbb P^n$ or $\mathbb P^n$ itself, we prove the existence of curves of any genus and high enough degree depending on the genus passing through the expected number $t$ of general points or…

Algebraic Geometry · Mathematics 2022-11-22 Ziv Ran

In this note we collect some results on the deformation theory of toric Fano varieties.

Algebraic Geometry · Mathematics 2022-06-22 Andrea Petracci

We study a wide class of affine varieties, which we call affine Fano varieties. By analogy with birationally super-rigid Fano varieties, we define super-rigidity for affine Fano varieties, and provide many examples and non-examples of…

Algebraic Geometry · Mathematics 2019-02-20 Ivan Cheltsov , Adrien Dubouloz , Jihun Park

It is known that a necessary condition for the existence of K\"ahler-Ricci solitons is the vanishing of the modified Futaki invariant introduced by Tian-Zhu. In a recent work of Berman-Nystr\"om, it was generalized for (singular) Fano…

Differential Geometry · Mathematics 2016-06-10 Ryosuke Takahashi

Determining when the birational automorphism group of a Fano variety is finite is an interesting and difficult problem. The main technique for studying this problem is by the Noether-Fano method. This method has been effective in studying…

Algebraic Geometry · Mathematics 2022-05-20 David Stapleton , Nathan Chen

We overview some recent results on Fano varieties giving evidence of their rigid nature under small deformations.

Algebraic Geometry · Mathematics 2009-11-04 Tommaso de Fernex , Christopher Hacon

We prove that a smooth well formed Picard rank one Fano complete intersection of dimension at least 2 in a toric variety is a weighted complete intersection.

Algebraic Geometry · Mathematics 2023-02-08 Victor Przyjalkowski , Constantin Shramov

Using an alternate description of support varieties of pairs of modules over a complete intersection, we give several new applications of such varieties, including results for support varieties of intermediate complete intersections.…

Commutative Algebra · Mathematics 2015-09-28 Petter Andreas Bergh , David A. Jorgensen

We study the cones of q-ample divisors on smooth complex varieties. In favourable cases, we identify a part where the closure of this cone and the nef cone have the same boundary. This is especially interesting for Fano (or almost Fano)…

Algebraic Geometry · Mathematics 2016-02-17 Robert Laterveer

A perfect PAC field containing an algebraically closed field is known to be $C_1$, i.e., every degeneration of a Fano complete intersection has a point. We prove that also every degeneration of a separably rationally connected variety has a…

Algebraic Geometry · Mathematics 2007-05-23 Jason Michael Starr

We introduce a canonical strip hypothesis for Fano varieties. We show that the canonical strip hypothesis for a Fano variety implies that the zeros of the Hilbert polynomial of embedded Calabi--Yau and general type hypersurfaces are located…

Algebraic Geometry · Mathematics 2009-03-13 V. Golyshev

We get sharp degree bound for generic smoothness and connectedness of the space of conics in low degree complete intersections which generalizes the old work about Fano scheme of lines on Hypersurfaces.

Algebraic Geometry · Mathematics 2013-07-25 Hong R. Zong

Under a hypothesis on $k$, $d$ and $n$ that is almost the best possible, we prove that for every smooth degree $d$ hypersurface in $P^n$, the $k$-plane sections dominate the moduli space of degree $d$ hypersurface in $P^k$. Using this we…

Algebraic Geometry · Mathematics 2007-05-23 Jason Michael Starr