English
Related papers

Related papers: K\"ahler packings and Seshadri constants on projec…

200 papers

Hypersimplices are well-studied objects in combinatorics, optimization, and representation theory. For each hypersimplex, we define a new family of subpolytopes, called r-stable hypersimplices, and show that a well-known regular unimodular…

Combinatorics · Mathematics 2016-03-17 Benjamin Braun , Liam Solus

We introduce and study the notion of atomic sheaves and complexes on higher-dimensional hyper-K\"ahler manifolds and show that they share many of the intriguing properties of simple sheaves on K3 surfaces. For example, we prove formality of…

Algebraic Geometry · Mathematics 2022-06-09 Thorsten Beckmann

We initiate the study of the norm-squared of the momentum map as a rigorous tool in infinite dimensions. In particular, we calculate the Hessian at a critical point, show that it is positive semi-definite along the complexified orbit, and…

Differential Geometry · Mathematics 2024-05-24 Tobias Diez , Tudor S. Ratiu

In this paper we study symplectic embedding questions for the $\ell_p$-sum of two discs in ${\mathbb R}^4$, when $1 \leq p \leq \infty$. In particular, we compute the symplectic inner and outer radii in these cases, and show how different…

Symplectic Geometry · Mathematics 2019-11-15 Yaron Ostrover , Vinicius G. B. Ramos

We derive necessary conditions for a complex projective structure on a complex surface to arise via the Levi-Civita connection of a (pseudo-)K\"ahler metric. Furthermore we show that the (pseudo-)K\"ahler metrics defined on some domain in…

Differential Geometry · Mathematics 2023-07-19 Thomas Mettler

We determine all complete projective special real surfaces. By the supergravity r-map, they give rise to complete projective special K\"ahler manifolds of dimension 6, which are distinguished by the image of their scalar curvature function.…

Differential Geometry · Mathematics 2017-05-17 Vicente Cortés , Malte Dyckmanns , David Lindemann

Using $\delta$-invariants and Newton--Okounkov bodies, we derive the optimal volume upper bound for K\"ahler manifolds with positive Ricci curvature, from which we get a new characterization of the complex projective space.

Differential Geometry · Mathematics 2020-09-30 Kewei Zhang

Given a semi-Riemannian $4$-manifold $(M,g)$ with two distinguished vector fields satisfying properties determined by their shear, twist and various Lie bracket relations, a family of K\"ahler metrics $g_K$ is constructed, defined on an…

Differential Geometry · Mathematics 2020-12-23 Amir Babak Aazami , Gideon Maschler

Mehta and Seshadri have proved that the set of equivalence classes of irreducible unitary representations of the fundamental group of a punctured compact Riemann surface, can be identified with equivalence classes of stable parabolic…

Algebraic Geometry · Mathematics 2020-12-29 C. Arusha , Sanjay Kumar Singh

Using dynamical stability of symplectic curvature flow, we show that on a compact Calabi-Yau manifold, any small symplectic deformation of a K\"ahler form remains K\"ahler.

Differential Geometry · Mathematics 2022-02-10 Jeffrey Streets , Gang Tian

For any given natural number $k$, this paper gives upper bounds on the radius of a packing of a complete hyperbolic surface of finite area by $k$ equal-radius disks in terms of the surface's topology. We show that the bounds given here are…

Geometric Topology · Mathematics 2018-06-11 Jason DeBlois

We study the geometry of exceptional loci of birational contractions of hyper-K\"ahler fourfolds that are of K3$^{[2]}$-type. These loci are conic bundles over K3 surfaces and we determine their classes in the Brauer group. For this we use…

Algebraic Geometry · Mathematics 2022-12-12 Bert van Geemen , Grzegorz Kapustka

We find an algorithm to compute the cohomology groups of spherical vector bundles on complex projective K3 surfaces, in terms of their Mukai vectors. In many good cases, we give significant simplifications of the algorithm. As an…

Algebraic Geometry · Mathematics 2023-02-08 Yeqin Liu

We generalize the notions of the Futaki invariant and extremal vector field of a compact K\"ahler manifold to the general almost-Kahler case and show the periodicity of the extremal vector field when the symplectic form represents an…

Differential Geometry · Mathematics 2010-04-22 Mehdi Lejmi

We study the existence of extremal K\"ahler metrics on K\"ahler manifolds. After introducing a notion of relative K-stability for K\"ahler manifolds, we prove that K\"ahler manifolds admitting extremal K\"ahler metrics are relatively…

Differential Geometry · Mathematics 2017-09-04 Ruadhaí Dervan

Motivated by the geometry of Levi degenerate CR hypersurfaces, we define a pre-K\"ahler structure on a complex manifold as a pre-symplectic structure compatible with the almost complex structure, i.e. a closed (1,1)-form. Extending Freeman…

Differential Geometry · Mathematics 2025-05-16 Omid Makhmali , David Sykes

We show that if a compact K\"ahler manifold admits a weighted extremal metric for the action of a torus, so too does its blowup at a relatively stable point that is fixed by both the torus action and the extremal field. This generalises…

Differential Geometry · Mathematics 2025-05-08 Michael Hallam

In this article we study asymptotic slopes of strongly semistable vector bundles on a smooth projective surface. A connection between asymptotic slopes and strong restriction theorem of a strongly semistable vector bundle is shown. We also…

Algebraic Geometry · Mathematics 2022-01-10 Mitra Koley , A. J. Parameswaran

A compactness theorem is proved for a family of K\"{a}hler surfaces with constant scalar curvature and volume bounded from below, diameter bounded from above, Ricci curvature bounded and the signature bounded from below. Furthermore, a…

Differential Geometry · Mathematics 2013-04-04 Hongliang Shao

This paper extends our earlier results to higher dimensions using a different approach, based on the rigidity of complex structures on certain domains.

Differential Geometry · Mathematics 2011-04-22 X-X. Chen , S. K. Donaldson
‹ Prev 1 8 9 10 Next ›