English
Related papers

Related papers: On K\"ahler metrisability of two-dimensional compl…

200 papers

We search for Riemannian metrics whose Levi-Civita connection belongs to a given projective class. Following Sinjukov and Mikes, we show that such metrics correspond precisely to suitably positive solutions of a certain projectively…

Differential Geometry · Mathematics 2011-08-22 Michael Eastwood , Vladimir S. Matveev

Given a projective structure on a three-dimensional manifold, we find explicit obstructions to the local existence of a Levi-Civita connection in the projective class. These obstructions are given by projectively invariant tensors…

Differential Geometry · Mathematics 2014-10-21 Maciej Dunajski , Michael Eastwood

We carry out the programme of R. Liouville \cite{Liouville} to construct an explicit local obstruction to the existence of a Levi--Civita connection within a given projective structure $[\Gamma]$ on a surface. The obstruction is of order 5…

Differential Geometry · Mathematics 2010-02-15 Robert L. Bryant , Maciej Dunajski , Michael Eastwood

We present a number of conditions which are necessary for an n-dimensional projective structure (M,[nabla]) to include the Levi-Civita connection nabla of some metric on M. We provide an algorithm, which effectively checks if a Levi-Civita…

Differential Geometry · Mathematics 2015-05-18 Pawel Nurowski

We derive some necessary conditions on a Riemannian metric $(M, g)$ in four dimensions for it to be locally conformal to K\"ahler. If the conformal curvature is non anti--self--dual, the self--dual Weyl spinor must be of algebraic type $D$…

Differential Geometry · Mathematics 2015-05-13 Maciej Dunajski , Paul Tod

We develop in detail the theory of c-projective geometry, a natural analogue of projective differential geometry adapted to complex manifolds. We realise it as a type of parabolic geometry and describe the associated Cartan or tractor…

Differential Geometry · Mathematics 2021-06-08 David M. J. Calderbank , Michael G. Eastwood , Vladimir S. Matveev , Katharina Neusser

A metric projective structure is a manifold equipped with the unparametrised geodesics of some pseudo-Riemannian metric. We make acomprehensive treatment of such structures in the case that there is a projective Weyl curvature nullity…

Differential Geometry · Mathematics 2017-11-28 A. Rod Gover , Vladimir S. Matveev

On an almost Hermitian manifold, we have two Hermitian scalar curvatures with respect to any canonical Hermitian connection defined by P. Gauduchon. Explicit formulas of these two Hermitian scalar curvatures are obtained in terms of…

Differential Geometry · Mathematics 2019-01-30 Jixiang Fu , Xianchao Zhou

We study Hermitian metrics with a Gauduchon connection being "K\"ahler-like", namely, satisfying the same symmetries for curvature as the Levi-Civita and Chern connections. In particular, we investigate $6$-dimensional solvmanifolds with…

Differential Geometry · Mathematics 2023-03-21 Daniele Angella , Antonio Otal , Luis Ugarte , Raquel Villacampa

C-projective structures are analogues of projective structures in the complex setting. The maximal dimension of the Lie algebra of c-projective symmetries of a complex connection on an almost complex manifold of C-dimension $n>1$ is…

Differential Geometry · Mathematics 2017-04-26 Boris Kruglikov , Vladimir Matveev , Dennis The

Let $X$ be a compact K\"ahler manifold. We prove that if $X$ admits a smooth Hermitian metric $\omega$ with quasi-positive second Chern-Ricci curvature $\mathrm{Ric}^{(2)}(\omega)$, then $X$ is projective and rationally connected. In…

Differential Geometry · Mathematics 2020-06-25 Xiaokui Yang

We report on a few interrelations between bi-Hermitian metrics and locally conformally K\"ahler metrics on complex surfaces.

Differential Geometry · Mathematics 2025-01-13 Massimiliano Pontecorvo

We introduce a class of hermitian metrics with {\em Lee potential}, that generalize the notion of l.c.K. metrics with potential introduced in \cite{ov} and show that in the classical examples of Calabi and Eckmann of complex structures on…

Differential Geometry · Mathematics 2012-08-22 Florin Belgun

We review how a reduction procedure along a principal fibration and an unfolding procedure associated to a suitable momentum map allow to describe the K\"ahler geometry of a finite dimensional complex projective spaces.

Mathematical Physics · Physics 2018-09-27 Giuseppe Marmo , Alessandro Zampini

We prove that locally conformally K\"ahler metrics on certain compact complex surfaces with odd first Betti number can be deformed to new examples of bi-Hermitian metrics.

Differential Geometry · Mathematics 2014-11-18 Vestislav Apostolov , Michael Bailey , Georges Dloussky

Based on its central role in the framework of real calculi, the existence of the Levi-Civita connection for real calculi over projective modules is studied, with a special emphasis placed on the simple module of N-dimensional complex…

Quantum Algebra · Mathematics 2023-09-12 Axel Tiger Norkvist

We establish a one-to-one correspondence between K\"ahler metrics in a given conformal class and parallel sections of a certain vector bundle with conformally invariant connection, where the parallel sections satisfy a set of non--linear…

Differential Geometry · Mathematics 2025-07-30 Maciej Dunajski , A. Rod Gover

The K\"ahler cone of a compact K\"ahler manifold carries a natural Riemannian metric, given by the intersection product of its cohomology ring. We give cohomological expressions for the Levi-Civita connection and curvature tensor of this…

Algebraic Geometry · Mathematics 2020-04-16 Gunnar Þór Magnússon

A Hermitian metric on a complex manifold of complex dimension $n$ is called {\em astheno-K\"ahler} if its fundamental $2$-form $F$ satisfies the condition $\partial \overline \partial F^{n - 2} =0$. If $n =3$, then the metric is {\em strong…

Differential Geometry · Mathematics 2014-02-26 Anna Fino , Adriano Tomassini

Motivated by a recent work of Chen-Zheng [8] on Strominger space forms, we prove that a compact Hermitian surface with pointwise constant holomorphic sectional curvature with respect to a Gauduchon connection $\nabla^t $ is either K\"ahler,…

Differential Geometry · Mathematics 2022-02-15 Haojie Chen , Xiaolan Nie
‹ Prev 1 2 3 10 Next ›