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Related papers: On Bismut Flat Manifolds

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We compute the full holonomy group of compact Lorentzian manifolds with parallel Weyl tensor, which are neither conformally flat nor locally symmetric, for the case where the fundamental group is contained in a distinguished subgroup G of…

Differential Geometry · Mathematics 2012-05-23 Daniel Schliebner

We investigate Bismut--Ambrose--Singer (BAS) manifolds, namely Hermitian manifolds whose Bismut connection has parallel torsion and parallel curvature. We first establish a canonical reduction theorem for complete, simply-connected BAS…

Differential Geometry · Mathematics 2026-05-05 Giuseppe Barbaro , Francesco Pediconi

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

Let $(M^n, g)$ be a compact K\"ahler manifold with nonpositive bisectional curvature. We show that a finite cover is biholomorphic and isometric to a flat torus bundle over a compact K\"ahler manifold $N^k$ with $c_1 < 0$. This confirms a…

Differential Geometry · Mathematics 2014-04-30 Gang Liu

We pursuit the research line proposed in \cite{YZ-Gflat} about the classification of Hermitian manifolds whose $s$-Gauduchon connection $\nabla^s =(1-\frac{s}{2})\nabla^c + \frac{s}{2}\nabla^b$ is flat, where $s \in \mathbb{R}$ and…

Differential Geometry · Mathematics 2023-03-31 Luigi Vezzoni , Bo Yang , Fangyang Zheng

The Lichnerowicz conjecture asserts that all harmonic manifolds are either flat or locally symmetric spaces of rank 1. This conjecture has been proved by Z.I. Szabo for harmonic manifolds with compact universal cover. E. Damek and F. Ricci…

Differential Geometry · Mathematics 2013-02-18 Gerhard Knieper , Norbert Peyerimhoff

An old conjecture in non-K\"ahler geometry states that, if a compact Hermitian manifold has constant holomorphic sectional curvature, then the metric must be K\"ahler (when the constant is non-zero) or Chern flat (when the constant is…

Differential Geometry · Mathematics 2025-10-01 Shuwen Chen , Fangyang Zheng

We consider non-Kaehler compact complex manifolds which are homogeneous under the action of a compact Lie group of biholomorphisms and we investigate the existence of special (invariant) Hermitian metrics on these spaces. We focus on a…

Differential Geometry · Mathematics 2016-08-30 Fabio Podestà

We consider homogeneous hypercomplex manifolds with a transitive action of a compact Lie group and we give a characterization of invariant HKT metrics on them. On every such hypercomplex manifold we prove the existence of an invariant…

Differential Geometry · Mathematics 2026-04-27 Lucio Bedulli , Lorenzo Marcocci

We prove that a compact contact threefold which is bimeromorphically equivalent to a Kaehler manifold and not rationally connected is the projectivised tangent bundle of a Kaehler surface.

Algebraic Geometry · Mathematics 2010-05-11 Kristina Frantzen , Thomas Peternell

This is a slightly altered version of the authors thesis from 2014. In the first main part we show that the quotient space of a compact, simply connected and nonnegatively curved Riemannian 4-manifold by an effective, isometric…

Differential Geometry · Mathematics 2015-10-07 Wolfgang Spindeler

We examine the class of compact Hermitian manifolds with constant holomorphic sectional curvature. Such manifolds are conjectured to be K\"ahler (hence a complex space form) when the constant is non-zero and Chern flat (hence a quotient of…

Differential Geometry · Mathematics 2022-10-18 Wu Zhou , Fangyang Zheng

We give a mathematical exposition of the Page metric, and introduce an efficient coordinate system for it. We carefully examine the submanifolds of the underlying smooth manifold, and show that the Page metric does not have positive…

Differential Geometry · Mathematics 2019-04-11 Mustafa Kalafat , Caner Koca

We prove that the universal covering of a complete locally symmetric normal metric contact pair manifold is a Calabi-Eckmann manifold. Moreover we show that a complete, simply connected, normal metric contact pair manifold such that the…

Differential Geometry · Mathematics 2011-10-31 G. Bande , D. E. Blair

We ask about the simply connected compact smooth 6-manifolds which can support structures of Calabi-Yau threefolds. In particular, we study the interesting case of Calabi-Yau threefolds $X$ with second betti number 3. We have a cup-product…

Algebraic Geometry · Mathematics 2023-05-16 P. M. H. Wilson

We classify compact surfaces with torsion-free affine connections for which every geodesic is a simple closed curve. In the process, we obtain completely new proofs of all the major results concerning the Riemannian case. In contrast to…

Differential Geometry · Mathematics 2007-05-23 Claude LeBrun , L. J. Mason

We study two natural problems concerning the scalar and the Ricci curvatures of the Bismut connection. Firstly, we study an analog of the Yamabe problem for Hermitian manifolds related to the Bismut scalar curvature, proving that, fixed a…

Differential Geometry · Mathematics 2022-12-13 Giuseppe Barbaro

We consider the unique Hermitian connection with totally skew-symmetric torsion on a Hermitian manifold. We prove that if the torsion is parallel and the holonomy is Sp(n)U(1), considered as a subgroup of U(2n) x U(1), then the manifold is…

Differential Geometry · Mathematics 2007-05-23 Bogdan Alexandrov

For a compact connected Lie group $G$ acting as isometries on a compact orientable Riemannian manifold $M^{n+1},$ and cohomogeneity not equal to 0 or 2, we prove the existence of a nontrivial embedded $G$-invariant minimal hypersurface,…

Differential Geometry · Mathematics 2020-07-07 Zhenhua Liu

We prove that the normal metric contact pairs with orthogonal characteristic foliations, which are either Bochner flat or locally conformally flat, are locally isometric to the Hopf manifolds. As a corollary we obtain the classification of…

Differential Geometry · Mathematics 2015-03-31 Gianluca Bande , David E. Blair , Amine Hadjar