English
Related papers

Related papers: On the Relation Between $G_2^*$ Structures and Alm…

200 papers

Almost paracontact almost paracomplex Riemannian manifolds of the lowest dimension 3 are considered. Such structures are constructed on a family of Lie groups and the obtained manifolds are studied. Curvature properties of these manifolds…

Differential Geometry · Mathematics 2021-05-21 Mancho Manev , Veselina Tavkova

We study 5-dimensional Riemannian manifolds that admit an almost contact metric structure. In particular, we generalize the class of quasi-Sasaki manifolds and characterize these structures by their intrinsic torsion. Among other things, we…

Differential Geometry · Mathematics 2012-11-14 Christof Puhle

We study generalized almost contact structures on odd-dimensional manifolds. We introduce a notion of integrability and show that the class of these structures is closed under symmetries of the Courant-Dorfman bracket, including T-duality.…

Differential Geometry · Mathematics 2015-12-11 Marco Aldi , Daniele Grandini

In this paper eleven basic classes of almost paracontact manifolds are introduced and some examples are constructed.

Differential Geometry · Mathematics 2009-03-20 Galia Nakova , Simeon Zamkovoy

The goal of this paper, using lifting theory it is to produce almost paracomplex struc- tures on the tangent bundle of almost Lorentzian r-paracontact manifold endowed with almost Lorentzian r-paracontact structure. Finally, we discuss the…

Differential Geometry · Mathematics 2009-03-03 Mehmet Tekkoyun

We overview the properties of non-infinitesimal deformations of G2-structures on seven-manifolds, and in particular, focus on deformations that lie in the seven-dimensional representation of G2 and are thus defined by a vector. We then…

Differential Geometry · Mathematics 2013-01-22 Sergey Grigorian

In this paper, left-invariant almost contact metric structures on three-dimensional non-unimodular Lie groups are investigated. It is proved that for every Riemannian Lie group, there is one of these structures. In addition, left-invariant…

Differential Geometry · Mathematics 2020-02-12 Pejhman Vatandoost-Miandehi , A. Razavi

A dualistic structure on a smooth Riemaniann manifold $M$ is a triple $(M,g,\nabla)$ with $g$ a Riemaniann metric and $\nabla$ an affine connection, generally assumed to be torsionless. From $g$ and $\nabla$, the dual connection $\nabla^*$…

Differential Geometry · Mathematics 2022-09-21 E. Gnandi , S. Puechmorel

We study almost bi-paracontact structures on contact manifolds. We prove that if an almost bi-paracontact structure is defined on a contact manifold $(M,\eta)$, then under some natural assumptions of integrability, $M$ carries two…

Differential Geometry · Mathematics 2013-06-18 Beniamino Cappelletti Montano

In this paper, we define almost paracontact and normal almost paracontact Finsler structures on a vector bundle and find some conditions for integrability of these structures. We define paracontact metric, para- Sasakian and K-paracontact…

Differential Geometry · Mathematics 2013-02-05 E. Peyghan , A. Tayebi , E. Sharahi

It is provided an overview of existed results concerning classification of contact metric, almost cosymplectic and almost Kenmotsu $(\kappa,\mu)$-manifolds. In the case of dimension three it is described in full details structure of contact…

Differential Geometry · Mathematics 2020-09-23 Piotr Dacko

This article deals with 3-forms on 6-dimensional manifodls, the first dimension where the classification of 3-forms is not trivial. There are three classes of multisymplectic 3-forms there. We study the class which is closely related to…

Differential Geometry · Mathematics 2007-05-23 Martin Panak , Jiri Vanzura

The algebra of exterior differential forms on a regular 3-Sasakian 7-manifold is investigated, with special reference to nearly-parallel $G_2$ 3-forms. This is applied to the study of 3-forms invariant under cohomogeneity-one actions by…

Differential Geometry · Mathematics 2025-08-04 Simon Salamon , Ragini Singhal

The object of investigation are the almost contact manifolds with B-metric in the lowest dimension three, constructed on Lie algebras. It is considered a relation between the classes in the Bianchi classification of three-dimensional real…

Differential Geometry · Mathematics 2014-12-30 Hristo Manev

Parabolic almost conformally symplectic structures were introduced in the first part of this series of articles as a class of geometric structures which have an underlying almost conformally symplectic structure. If this underlying…

Differential Geometry · Mathematics 2018-09-21 Andreas Cap , Tomas Salac

In this paper we consider a manifold $(M,\nabla )$ with a symmetric linear connection $\nabla $ which induces on the cotangent bundle $T^*M$ of $M$ a semi-Riemannian metric $\overline g$ with a neutral signature. The metric $\overline g$ is…

Differential Geometry · Mathematics 2018-03-28 Cornelia-Livia Bejan , Galia Nakova

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

We give simple characterizations of contact 1-forms in terms of Dirac structures. We also relate normal almost contact structures to the theory of Dirac structures.

Differential Geometry · Mathematics 2016-08-16 David Iglesias-Ponte , Aïssa Wade

Relevant to top-down ${\cal M}$-theory dual of large-$N$ thermal QCD-like theories at intermediate coupling, induced by the $G_2$ structure supported by the closed $M_7$ - a warped product of the ${\cal M}$-theory circle and a…

High Energy Physics - Theory · Physics 2025-07-22 Aalok Misra , Gopal Yadav

On 5-dimensional almost contact B-metric manifolds, the form of any K\"ahler-type tensor (i.e. a tensor satisfying the properties of the curvature tensor of the Levi-Civita connection in the special class of the parallel structures on the…

Differential Geometry · Mathematics 2015-05-06 Mancho Manev , Miroslava Ivanova