English
Related papers

Related papers: Remarks on toric manifolds whose Chern characters …

200 papers

We show that any toric Fano manifold of dimension at most eight with the positive second Chern character is isomorphic to the projective space by using polymake.

Algebraic Geometry · Mathematics 2020-08-31 Yuji Sano , Hiroshi Sato , Yusuke Suyama

In this paper we address Fano manifolds with positive higher Chern characters. They are expected to enjoy stronger versions of several of the nice properties of Fano manifolds. For instance, they should be covered by higher dimensional…

In this article we give a necessary and sufficient condition to characterize projective submanifolds in ${\mathbb P}^N$ with codimensions 2 and 3. The conditions involve the Chern classes of the manifold and a very ample line bundle on the…

Differential Geometry · Mathematics 2020-07-21 Ping Li , Fangyang Zheng

In this notes we classify toric Fano 4-folds having positive second Chern Character.

Algebraic Geometry · Mathematics 2011-09-06 Edilaine Ervilha Nobili

For any $n\geq 3$, we explicitly construct smooth projective toric $n$-folds of Picard number $\geq 5$, where any nontrivial nef line bundles are big.

Algebraic Geometry · Mathematics 2008-10-24 Osamu Fujino , Hiroshi Sato

We prove that a smooth rationally connected projective threefold of Picard number two is toric if and only if it admits an int-amplified endomorphism. As a corollary, we show that a totally invariant smooth curve of a non-isomorphic…

Algebraic Geometry · Mathematics 2025-06-18 Zelong Chen , Sheng Meng , Guolei Zhong

It is known that Chern characteristic numbers of compact complex manifolds cannot have arbitrary values. They satisfy certain divisability conditions. W. Ebeling and S. M. Gusein-Zade gave a definition of Chern characteristic numbers of…

Algebraic Geometry · Mathematics 2014-08-15 A. Y. Buryak

In this paper, we investigate Fano manifolds whose Chern characters satisfy some positivity conditions. We prove that such manifolds admit long chains of higher order minimal families of rational curves and are covered by higher rational…

Algebraic Geometry · Mathematics 2024-07-19 Taku Suzuki

For every complete toric variety, there exists a projective toric variety which is isomorphic to it in codimension one. In this paper, we show that every smooth non-projective complete toric threefold of Picard number at most five becomes…

Algebraic Geometry · Mathematics 2025-07-15 Osamu Fujino , Hiroshi Sato

We give a reduction of the conjecture that for terminal projective threefolds whose anticanonical divisors are nef, the second Chern classes are pseudo-effective. On the other hand, some effective non-vanishing results are obtained as…

Algebraic Geometry · Mathematics 2016-09-07 Qihong Xie

We show that every set of numbers that occurs as the set of Chern numbers of an almost complex manifold $M^{2n}$, $n\geqslant 3$, may be realized as the set of Chern numbers of a connected almost complex manifold with an almost complex…

Algebraic Topology · Mathematics 2015-06-18 Andrey Kustarev

We first construct closed spherical CR manifolds of dimension at least five having non-trivial first Chern class with real coefficients. We next prove a constraint on Chern classes with real coefficients of (not necessarily closed)…

Differential Geometry · Mathematics 2022-10-13 Yuya Takeuchi

We show by example that the Chern numbers c_1^3 and c_1 c_2 of a complex 3-fold are not determined by the topology of the underlying smooth compact 6-manifold. In fact, we observe that infinitely many different values of a Chern number can…

Algebraic Geometry · Mathematics 2007-05-23 Claude LeBrun

We give various examples of Q-factorial projective toric varieties such that the sum of the squared torus invariant prime divisors is positive. We also determine the generators for the cone of effective $2$-cycles on a toric variety of…

Algebraic Geometry · Mathematics 2019-12-18 Hiroshi Sato , Yusuke Suyama

We show that some important classes of weak Fano $3$-folds of Picard rank $2$ do not satisfy Bott vanishing. Using this we show that any smooth projective $3$-fold $X$ of Picard rank $2$ with $-K_X$ nef which is the image of a projective…

Algebraic Geometry · Mathematics 2025-09-05 Supravat Sarkar

In this paper we show that the Chern numbers of a smooth Mori fibre space in dimension three are bounded in terms of the underlying topological manifold. We also generalise a theorem of Cascini and the second named author on the boundedness…

Algebraic Geometry · Mathematics 2019-06-05 Stefan Schreieder , Luca Tasin

General expressions are given for the coefficients of Chern forms up to the 13th order in curvature in terms of the Riemann-Christoffel curvature tensor and some of its concomitants (e.g., Pontrjagin's characteristic tensors) for…

General Relativity and Quantum Cosmology · Physics 2007-05-23 C. C. Briggs

We study motivic Chern classes of cones. First we show examples of projective cones of smooth curves such that their various $K$-classes (sheaf theoretic, push-forward and motivic) are all different. Then we show connections between the…

Algebraic Geometry · Mathematics 2020-06-22 László M. Fehér

We determine the Chern characters of two projective modules over the fuzzy sphere and calculate the corresponding topological charges (Chern numbers). These turn out to have corrections - compared to the commutative limit - induced by the…

Mathematical Physics · Physics 2007-05-23 Harald Grosse , Christian W. Rupp

This note outlines some first steps in the classification of Fano manifolds for which $c_1^2-2c_2$ is positive or nef.

Algebraic Geometry · Mathematics 2007-05-23 A. J. de Jong , Jason Michael Starr
‹ Prev 1 2 3 10 Next ›