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A rigidity result for a class of compact generalized quasi-Einstein manifolds with constant scalar curvature is obtained. Moreover, under some geometric assumptions, the rigidity for the noncompact case is also proved. Considering non…

Differential Geometry · Mathematics 2021-12-09 Antonio Airton Freitas Filho , Keti Tenenblat

By a special symplectic connection we mean a torsion free connection which is either the Levi-Civita connection of a Bochner-K\"ahler metric of arbitrary signature, a Bochner-bi-Lagrangian connection, a connection of Ricci type or a…

Differential Geometry · Mathematics 2009-09-11 Michel Cahen , Lorenz J. Schwachhöfer

In this article we introduce a natural extension of the well-studied equation for harmonic maps between Riemannian manifolds by assuming that the target manifold is equipped with a connection that is metric but has non-vanishing torsion.…

Differential Geometry · Mathematics 2021-07-05 Volker Branding

The author is planning if possible classify all three-dimensional $(\kappa,\mu)$-manifolds wether contact metric, almost cosymplectic, para-contact metric, almost para-cosymplectic. Of course classification in contact or almost cosymplectic…

Differential Geometry · Mathematics 2020-06-30 Piotr Dacko

The vector space of the tensors $\mathcal F$ of type (0,3) having the same symmetries as the covariant derivative of the fundamental form of an almost contact metric manifold is considered. A scheme of decomposition of $\mathcal F$ into…

Differential Geometry · Mathematics 2011-10-20 Valentin A. Alexiev , Georgi T. Ganchev

In the first part of this series of papers we developed the invariant differentiation with respect to a Cartan connection, we described this procedure in the terms of the underlying principal connections, and we discussed applications of…

dg-ga · Mathematics 2008-02-03 Andreas Cap , Jan Slovak , Vladimir Soucek

In this paper we study some geometrical objects (d-tensors, multi-time semisprays of polymomenta and nonlinear connections) on the dual 1-jet vector bundle $J^{1*}(\cal{T}, M)\to \cal{T}\times M$. Some geometrical formulas, which connect…

Differential Geometry · Mathematics 2010-07-26 Gheorghe Atanasiu , Mircea Neagu

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

A tensor invariant is defined on a quaternionic contact manifold in terms of the curvature and torsion of the Biquard connection involving derivatives up to third order of the contact form. This tensor, called quaternionic contact conformal…

Differential Geometry · Mathematics 2010-03-12 Stefan Ivanov , Dimiter Vassilev

If the Einstein-Hilbert action ${\cal L}_{\rm EH}\propto R$ is re-expressed in Riemann-Cartan spacetime using the gauge fields of translations, the vierbein field $h^\alpha{}_\mu$, and the gauge field of local Lorentz transformations, the…

General Relativity and Quantum Cosmology · Physics 2017-08-23 H. Kleinert

In this paper, we consider the CPE conjecture in the frame-work of $K$-contact and $(\kappa, \mu)$-contact manifolds. First, we prove that if a complete $K$-contact metric satisfies the CPE is Einstein and is isometric to a unit sphere…

Differential Geometry · Mathematics 2017-11-17 Amalendu Ghosh , Dhriti Sundar Patra

We study the topology of a complete asymptotically hyperbolic Einstein manifold such that its conformal boundary has positive Yamabe invariant. We proved that all maps from such manifold into any nonpositively curved manifold are…

Differential Geometry · Mathematics 2007-05-23 Naichung Conan Leung , Tom Yau-heng Wan

We construct a canonically defined affine connection in sub-Riemannian contact geometry. Our method mimics that of the Levi-Civita connection in Riemannian geometry. We compare it with the Tanaka-Webster connection in the three-dimensional…

Differential Geometry · Mathematics 2016-04-21 Michael Eastwood , Katharina Neusser

In this article, we investigate the geometry of compact quasi-Einstein manifolds with boundary. We show that a $3$-dimensional simply connected compact quasi-Einstein manifold with boundary and constant scalar curvature is isometric, up to…

Differential Geometry · Mathematics 2026-04-10 Johnatan Costa , Ernani Ribeiro , Detang Zhou

We establish a parametric extension $h$-principle for overtwisted contact structures on manifolds of all dimensions, which is the direct generalization of the $3$-dimensional result from \cite{Eli89}. It implies, in particular, that any…

Symplectic Geometry · Mathematics 2014-10-14 Matthew Strom Borman , Yakov Eliashberg , Emmy Murphy

Generalized $(\kappa ,\mu )$ structures occur in dimension 3 only. In this dimension 3, only K-contact structures can occur as generalized Eta-Einstein. On closed manifolds, Eta-Einstein, K-contact structures which are not D-homothetic to…

Differential Geometry · Mathematics 2023-10-09 Philippe Rukimbira

A local classification of the Hermitian manifolds with flat associated connection is given. Hermitian manifolds admitting locally a conformal metric with flat associated connection are characterized by a curvature identity. Locally…

Differential Geometry · Mathematics 2011-09-15 Georgi Ganchev , Ognian Kassabov

We construct a mathematical framework for twisted N=2 supersymmetric topological quantum field theory on a 4-manifold. Supersymmetry in flat space is defined and the twist homomorphism is constructed, giving us a supermanifold that is the…

High Energy Physics - Theory · Physics 2007-05-23 Gregory Langmead

Manifolds endowed with torsion and nonmetricity are interesting both from the physical and the mathematical points of view. In this paper, we generalize some results presented in the literature. We study Einstein manifolds (i.e., manifolds…

General Relativity and Quantum Cosmology · Physics 2020-02-19 Dietmar Silke Klemm , Lucrezia Ravera

For an almost contact metric manifold $N$, we find conditions for which either the total space of an $S^1$-bundle over $N$ or the Riemannian cone over $N$ admits a strong K\"ahler with torsion (SKT) structure. In this way we construct new…

Differential Geometry · Mathematics 2010-11-19 Marisa Fernandez , Anna Fino , Luis Ugarte , Raquel Villacampa