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Related papers: Four-dimensional Fano toric complete intersections

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We present the complete classification of smooth toric Fano threefolds, known to the algebraic geometry literature, and perform some preliminary analyses in the context of brane-tilings and Chern-Simons theory on M2-branes probing…

High Energy Physics - Theory · Physics 2011-09-08 Amihay Hanany , Yang-Hui He

Our earlier proof of mirror formulas for genus 0 Gromov -- Witten invariants of Fano and Calabi -- Yau toric complete intersections is illustrated in the example of quintic 3-folds.

Algebraic Geometry · Mathematics 2007-05-23 Alexander B. Givental

We provide a complete classification of possible configurations of mutually pairwise touching infinite cylinders in Euclidian 3D space. It turns out that there is a maximum number of such cylinders possible in 3D independently on the shape…

Metric Geometry · Mathematics 2016-05-18 Peter V. Pikhitsa , Stanislaw Pikhitsa

We investigate the lines tangent to four triangles in R^3. By a construction, there can be as many as 62 tangents. We show that there are at most 162 connected components of tangents, and at most 156 if the triangles are disjoint. In…

Metric Geometry · Mathematics 2010-03-29 Hervé Brönnimann , Olivier Devillers , Sylvain Lazard , Frank Sottile

In every odd dimension $n\geq 5$ we exhibit large classes of closed $n$-dimensional manifolds which admit infinitely many different geometries of positive Ricci curvature, i.e., manifolds for which their moduli space of metrics of positive…

Differential Geometry · Mathematics 2025-11-17 Anand Dessai

A representation for compact 3-manifolds with non-empty non-spherical boundary via 4-colored graphs (i.e., 4-regular graphs endowed with a proper edge-coloration with four colors) has been recently introduced by two of the authors, and an…

Geometric Topology · Mathematics 2017-12-06 P. Cristofori , E. Fominykh , M. Mulazzani , V. Tarkaev

Complete intersections may be unexpectedly simple over fields of positive characteristic: for instance, they may be unirational despite being of general type. One explanation is given by profiles, structure that tracks the special shape of…

Algebraic Geometry · Mathematics 2025-08-13 Raymond Cheng

In this paper we classify n-dimensional Fano manifolds with index >=n-2 and positive second Chern character.

Algebraic Geometry · Mathematics 2012-06-08 Carolina Araujo , Ana-Maria Castravet

In this paper we compute the cohomology of the Fano varieties of $k$-planes in the smooth complete intersection of two quadrics in $\mathbb{P}^{2g+1}$, using Springer theory for symmetric spaces.

Algebraic Geometry · Mathematics 2020-06-23 Tsao-Hsien Chen , Kari Vilonen , Ting Xue

We solve the infinitesimal Torelli problem for $3$-dimensional quasi-smooth ${\mathbb{Q}}$-Fano hypersurfaces with at worst terminal singularities. We also find infinite chains of double coverings of increasing dimension which alternatively…

Algebraic Geometry · Mathematics 2019-02-15 Enrico Fatighenti , Luca Rizzi , Francesco Zucconi

We prove that every quaternionic-contact structure can be embedded in a quaternionic manifold and define a second fundamental form for a such embedding.

Differential Geometry · Mathematics 2007-05-23 David Duchemin

We prove that smooth Fano 5-folds with nef tangent bundles and Picard numbers greater than one are rational homogeneous manifolds.

Algebraic Geometry · Mathematics 2013-04-10 Kiwamu Watanabe

For a Fano manifold of pseudo-index at least 3 and $c_1^2-2c_2$ nef, we show irreducibility of certain spaces of curves on the Fano manifold implies the manifold is a union of rational surfaces.

Algebraic Geometry · Mathematics 2007-05-23 A. J. de Jong , Jason Michael Starr

We study some symplectic geometric aspects of rationally connected 4-folds. As a corollary, we prove that any smooth projective 4-fold symplectic deformation equivalent to a Fano 4-fold of pseudo-index at least 2 or a rationally connected…

Algebraic Geometry · Mathematics 2012-08-22 Zhiyu Tian

We describe explicitly the chamber structure of the movable cone for a general complete intersection Calabi--Yau threefold in a non-split $(n + 4)$-dimensional $\mathbb{P}^{n}$-ruled Fano manifold of index $n + 1$ and Picard number two.…

Algebraic Geometry · Mathematics 2023-11-17 Atsushi Ito , Ching-Jui Lai , Sz-Sheng Wang

In this short note we prove that in many cases the failure of a variety to be separably rationally connected is caused by the instability of the tangent sheaf (if there are no other obvious reasons). A simple application of the results…

Algebraic Geometry · Mathematics 2014-07-30 Zhiyu Tian

We give an explicit construction for the extension of a symmetric determinantal quartic K3 surface to a Fano 6-fold. Remarkably, the moduli of the 6-fold extension are in one-to-one correspondence with the moduli of the quartic surface. As…

Algebraic Geometry · Mathematics 2009-10-01 Stephen Coughlan

We construct well-formed and quasismooth terminal Fano 4-folds of index 1 in low codimension containing at worst isolated orbifold points. We provide a certain classification of these varieties where their images under the anitcanonical…

Algebraic Geometry · Mathematics 2025-06-30 Muhammad Imran Qureshi

We describe the closed cone of moving curves of smooth Fano three- and fourfolds by giving finitely many equations that cut out the cone. The equations are induced by the exceptional divisors of divisorial contractions and by nef divisors…

Algebraic Geometry · Mathematics 2009-02-03 Sammy Barkowski

We classify the polarized symplectic automorphisms of Fano varieties of smooth cubic fourfolds (equipped with the Pl\"ucker polarization) and study the fixed loci.

Algebraic Geometry · Mathematics 2013-03-15 Lie Fu