English
Related papers

Related papers: Higher order obstructions to the desingularization…

200 papers

There is an obstruction to the existence of K\"ahler -Einstein metrics which is used to define the GIT weight for K-stability, and it has been extended to various geometric problems. This survey paper considers such extended obstructions to…

Differential Geometry · Mathematics 2018-09-06 Akito Futaki , Hajime Ono

We show that K\"ahler-Einstein metrics with cone singularities along simple normal crossing (SNC) divisors define RCD spaces, both in the compact setting and in certain non-compact cases, thereby producing many examples of Einstein RCD…

Differential Geometry · Mathematics 2026-01-27 Martin de Borbon , Cristiano Spotti

If $M$ is the underlying smooth oriented $4$-manifold of a Del Pezzo surface, we consider the set of Riemannian metrics $h$ on $M$ such that $W^+(\omega , \omega )> 0$, where $W^+$ is the self-dual Weyl curvature of $h$, and $\omega$ is a…

Differential Geometry · Mathematics 2015-04-29 Claude LeBrun

We construct new complete Einstein metrics on smoothly bounded strictly pseudoconvex domains in Stein manifolds. This is done by deforming the K\"ahler-Einstein metric of Cheng and Yau, the approach that generalizes the works of Roth and…

Differential Geometry · Mathematics 2019-07-01 Yoshihiko Matsumoto

We present an explicit upper bound on the number of isolated homogeneous Einstein metrics on compact homogeneous spaces whose isotropy representations consist of pairwise inequivalent irreducibles. This is the BKK bound of the corresponding…

Differential Geometry · Mathematics 2025-09-15 Renato G. Bettiol , Hannah Friedman

We study locally conformal calibrated $G_2$-structures whose underlying Riemannian metric is Einstein, showing that in the compact case the scalar curvature cannot be positive. As a consequence, a compact homogeneous $7$-manifold cannot…

Differential Geometry · Mathematics 2020-08-11 Anna Fino , Alberto Raffero

Back in 1985, Wang and Ziller obtained a complete classification of all homogeneous spaces of compact simple Lie groups on which the standard or Killing metric is Einstein. The list consists, beyond isotropy irreducible spaces, of 12…

Differential Geometry · Mathematics 2023-01-03 Emilio A. Lauret , Jorge Lauret

We obtain a volume growth and curvature decay result for various classes of complete, noncompact Riemannian metrics in dimension 4; in particular our method applies to anti-self-dual or Kahler metrics with zero scalar curvature, and metrics…

Differential Geometry · Mathematics 2009-11-10 Gang Tian , Jeff Viaclovsky

It is an important problem in differential geometry to find non-naturally reductive homogeneous Einstein metrics on homogeneous manifolds. In this paper, we consider this problem for some coset spaces of compact simple Lie groups. A new…

Differential Geometry · Mathematics 2017-03-29 Zaili Yan , Shaoqiang Deng

Let (M,h) be a compact 4-dimensional Einstein manifold, and suppose that h is Hermitian with respect to some complex structure J on M. Then either (M,J,h) is Kaehler-Einstein, or else, up to rescaling and isometry, it is one of the…

Differential Geometry · Mathematics 2010-10-04 Claude LeBrun

We prove that there are infinitely many pairs of homeomorphic non-diffeomorphic smooth 4-manifolds, such that in each pair one manifold admits an Einstein metric and the other does not. We also show that there are closed 4-manifolds with…

Differential Geometry · Mathematics 2014-11-11 D. Kotschick

We refine the regularity of noncollapsed limits of 5-dimensional manifolds with bounded Ricci curvature. In particular, for noncollapsed limits of Einstein 5-manifolds, we prove that (1) tangent cones are unique of the form…

Differential Geometry · Mathematics 2026-02-17 Yiqi Huang , Tristan Ozuch

Let $M=G/K$ be a compact homogeneous space and assume that $G$ and $K$ have many simple factors. We show that the topological condition of having maximal third Betti number, in the sense that $b_3(M)=s-1$ if $G$ has $s$ simple factors, so…

Differential Geometry · Mathematics 2024-10-18 Jorge Lauret , Cynthia Will

In this paper, we establish a compactness result for a class of conformally compact Einstein metrics defined on manifolds of dimension $d\ge 4$. As an application, we derive the global uniqueness of a class of conformally compact Einstein…

Differential Geometry · Mathematics 2026-01-29 Sun-Yung A. Chang , Yuxin Ge , Xiaoshang Jin , Jie Qing

This undergraduate thesis is focused on introducing the reader to concepts related to the search for topological obstructions to the existence of compact gradient shrinking Ricci soliton metrics in dimension four. It contains a discussion…

Differential Geometry · Mathematics 2025-10-31 Cameron MacMahon

We study Einstein metrics on smooth compact 4-manifolds with an edge-cone singularity of specified cone angle along an embedded 2-manifold. To do so, we first derive modified versions of the Gauss-Bonnet and signature theorems for arbitrary…

Differential Geometry · Mathematics 2017-05-17 Michael Atiyah , Claude LeBrun

We show that there exist smooth, simply connected, four-dimensional spin manifolds which do not admit Einstein metrics, but nonetheless satisfy the strict Hitchin-Thorpe inequality. Our construction makes use of the Bauer/Furuta cohomotopy…

Differential Geometry · Mathematics 2007-05-23 Masashi Ishida , Claude LeBrun

We derive new, sharp lower bounds for certain curvature functionals on the space of Riemannian metrics of a smooth compact 4-manifold with a non-trivial Seiberg-Witten invariant. These allow one, for example, to exactly compute the infimum…

Differential Geometry · Mathematics 2009-10-31 Claude LeBrun

We introduce a large class of canonical K\"ahler metrics, called in this paper well-behaved, extending metrics induced by complex space forms. We study K\"ahler--Ricci iterations of well-behaved metrics on compact and non-compact K\"ahler…

Differential Geometry · Mathematics 2023-07-24 Andrea Loi , Giovanni Placini

For a sequence of extrinsic or intrinsic biharmonic maps $u_j: M_j\rightarrow N$ from a sequence of non-collapsed degenerating closed Einstein 4-manifolds $(M_j,g_j)$ with bounded Einstein constants, bounded diameters and bounded $L^2$…

Differential Geometry · Mathematics 2021-04-20 Youmin Chen , Miaomiao Zhu