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Related papers: On the Chern numbers of a smooth threefold

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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

We prove that if $X---> X^+$ is a threefold terminal flip, then $c_1(X).c_2(X)\leq c_1(X^+).c_2(X^+)$ where $c_1(X)$ and $c_2(X)$ denote the Chern classes. This gives the affirmative answer to a Question by Xie \cite{Xie2}. We obtain the…

Algebraic Geometry · Mathematics 2017-01-26 Jheng-Jie Chen

Let C be a smooth curve on an index 1 terminal 3-fold. We investigate the existence of extremal terminal divisorial contractions Y-->X that contract an irreducible surface E to C. We consider cases in respect to the singularities of the…

Algebraic Geometry · Mathematics 2007-05-23 Nikolaos Tziolas

In 1954 Hirzebruch asked which linear combinations of Chern numbers are topological invariants of smooth complex projective varieties. We give a complete answer to this question in small dimensions, and also prove partial results without…

Geometric Topology · Mathematics 2008-04-18 D. Kotschick

We show that 3-fold terminal flips and divisorial contractions may be factored into a sequence of flops, blow-downs to a smooth curve in a smooth 3-fold or divisorial contractions to points with minimal discrepancies.

Algebraic Geometry · Mathematics 2013-04-23 Jungkai Alfred Chen

Topological invariants, such as the Chern number, characterise topological phases of matter. Here we provide a method to detect Chern numbers in systems with two distinct species of fermion, such as spins, orbitals or several atomic states.…

Let X be a smooth threefold. We show that if $X_i\dashrightarrow X_{i+1}$ is a flip which appears in the $K_X$-MMP, then $c_1(X_i)^3-c_1(X_{i+1})^3$ is bounded by a constant depending only on $b_2(X)$.

Algebraic Geometry · Mathematics 2024-11-12 Paolo Cascini , Hsin-Ku Chen

In this paper the three-dimensional divisorial contractions $f\colon Y\to (X\ni P)$ are classified provided that $\Exc f=E$ is an irreducible divisor, $f(E)=P$, the variety $Y$ has canonical singularities and $(X\ni P)$ is a toric terminal…

Algebraic Geometry · Mathematics 2014-11-24 S. A. Kudryavtsev

We prove that each divisorial contraction to a curve between terminal threefolds is a weighted blow-up under a suitable embedding. Moreover, we give a classification of the weighted blow-ups assuming that the curve is smooth.

Algebraic Geometry · Mathematics 2024-11-26 Hsin-Ku Chen , Jheng-Jie Chen , Jungkai A. Chen

We determine all Chern numbers of smooth complex projective varieties of dimension at least four which are determined up to finite ambiguity by the underlying smooth manifold. We also give an upper bound on the dimension of the space of…

Algebraic Geometry · Mathematics 2018-10-31 Stefan Schreieder , Luca Tasin

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

Following the first paper, we continue to study Mori extractions from singular curves centred in a smooth 3-fold. We treat the case where the divisorial extraction exists in relative codimension at most 3.

Algebraic Geometry · Mathematics 2016-09-09 Tom Ducat

In this paper we study the concept of characteristic numbers and Chern slopes in the context of curve configurations in the real and complex projective plane. We show that some extremal line configurations inherit the same asymptotic…

Algebraic Geometry · Mathematics 2023-04-20 Adam Czapliński , Piotr Pokora

We prove that a rational linear combination of Chern numbers is an oriented diffeomorphism invariant of smooth complex projective varieties if and only if it is a linear combination of the Euler and Pontryagin numbers. In dimension at least…

Geometric Topology · Mathematics 2011-11-24 D. Kotschick

Combinatorial ideas are developed in this article to study Chern numbers on ample and numerically effective vector bundles. An effective lower bound for Chern numbers of ample vector bundles is established, which makes some progress towards…

Differential Geometry · Mathematics 2025-07-30 Ping Li

The theory of the higher Chern numbers in the presence of strong disorder is developed. Sharp quantization and homotopy invariance conditions are provided. The relevance of the result to the field of strongly disordered topological…

Mathematical Physics · Physics 2013-11-14 Emil Prodan , Bryan Leung , Jean Bellissard

The use of the physical variables in the fashion of Dirac in the three-dimensional Chern-Simons theories is presented. Our previous results are reinterpreted in a new aspect.

High Energy Physics - Theory · Physics 2007-05-23 Mu-In Park

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

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 investigate properties and describe examples of tilt-stable objects on a smooth complex projective threefold. We give a structure theorem on slope semistable sheaves of vanishing discriminant, and describe certain Chern classes for which…

Algebraic Geometry · Mathematics 2012-09-14 Jason Lo , Yogesh More
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