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Related papers: (a, 1)f structures on product of spheres

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In this paper we study almost complex and almost para-complex Cayley structures on six-dimensional pseudo-Riemannian spheres in the space of purely imaginary octaves of the split Cayley algebra $\mathbf{Ca}'$. It is shown that the Cayley…

Differential Geometry · Mathematics 2018-07-24 N. K. Smolentsev

There are introduced and studied a pair of associated Schouten-van Kampen affine connections adapted to the paracontact distribution and an almost paracontact almost paracomplex Riemannian structure generated by the pair of associated…

Differential Geometry · Mathematics 2021-05-21 Hristo Manev , Mancho Manev

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

In the paper, we first study more general models, where $F$ has constant rank and is based on weak metric structures (introduced by the first author and R. Wolak), which generalize almost complex and almost contact metric $f$-contact…

Differential Geometry · Mathematics 2025-12-24 Vladimir Rovenski , Milan Zlatanović

Is is known that the loop space associated to a Riemannian manifold admits a quasi-symplectic structure. This article shows that this structure is not likely to recover the underlying Riemannian metric by proving a result that is a strong…

Symplectic Geometry · Mathematics 2010-09-16 Vicente Munoz , Francisco Presas

In this paper we obtain the structure equation of a contact-complex Riemannian submersion and give some applications of this equation in the study of almost cosymplectic manifolds with Kaehler fibres.

Differential Geometry · Mathematics 2011-06-01 Stere Ianus , Adrian Mihai Ionescu , Raluca Mocanu , Gabriel Eduard Vilcu

There are studied in details 5-dimensional pseudo-Riemannian manifolds equipped with the structure analogous to the almost cosymplectic (almost coKaehler) structure. The curvature by assumption commutes with the structure affinor and all…

Differential Geometry · Mathematics 2013-08-30 Piotr Dacko

We investigate 7 dimensional almost para-contact metric structures induced by the 3-forms of $G_2^*$ Structures. We calculate the projections that determine to which class the almost para-contact structure belongs, by using the properties…

Differential Geometry · Mathematics 2020-07-30 Sirin Aktay

In this paper we construct and study almost paracontact metric structures $(\varphi ,\xi ,\eta ,g)$ on a 3-dimensional Walker manifold $(M,g)$ with respect to a local basis only by the coordinate functions of a unit space-like vector field…

Differential Geometry · Mathematics 2025-09-29 Galia Nakova , Cornelia-Livia Bejan

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 describe the automorphisms of a singular multicontact structure, that is a generalisation of the Martinet distribution. Such a structure is interpreted as a para-CR structure on a hypersurface M of a direct product space R^2 x R^2. We…

Differential Geometry · Mathematics 2014-09-09 Alessandro Ottazzi , Gerd Schmalz

We define and study natural $\mathrm{SU}(2)$-structures, in the sense of Conti-Salamon, on the total space $\cal S$ of the tangent sphere bundle of any given oriented Riemannian 3-manifold $M$. We recur to a fundamental exterior…

Differential Geometry · Mathematics 2020-10-19 R. Albuquerque

We consider a complete, totally umbilical hypersurface $M$ of Riemannian space $(\hat{R}^n, \hat{g})$ induced by a Minkowski space $(R^n, F)$. Under certain conditions we prove that $M$ is isometric to a "round" hypersphere of the $(n +…

Differential Geometry · Mathematics 2014-06-03 Tran Quoc Binh

In this paper, almost product-like Riemannian manifolds are investigated. Basic properties on tangential hypersurfaces of almost product-like Riemannian manifolds are obtained. Some examples of tangential hypersurfaces are presented. Some…

Differential Geometry · Mathematics 2022-12-08 Esra Erkan , Kazuhiko Takano , Mehmet Gulbahar

We study the properties of a generalized metallic, a generalized product and a generalized complex structure induced on the generalized tangent bundle of $M$ by a metallic Riemannian structure $(J,g)$ on $M$, providing conditions for their…

Differential Geometry · Mathematics 2025-08-04 Adara M. Blaga , Antonella Nannicini

We give some concrete examples of moduli spaces of connections. Precisely, we explain how to explicitly construct the moduli spaces of rank 2 fuchsian systems and logarithmic connections on the Riemann sphere with 4 poles. The former ones…

Classical Analysis and ODEs · Mathematics 2015-03-24 Frank Loray

Some geometric structures with associated Riemannian metrics have been considered in the book.

Differential Geometry · Mathematics 2008-05-23 Alexander A. Ermolitsky

We consider for structure groups ${\rm SU}(n)\,\subset\, {\rm SL}(n,\mathbb C)$ a densely defined toric structure on the moduli of framed parabolic sheaves on a three-punctured sphere, which degenerates to an actual toric structure. In…

Algebraic Geometry · Mathematics 2023-02-03 Indranil Biswas , Jacques Hurtubise

Two-dimensional almost-Riemannian structures are generalized Riemannian structures on surfaces for which a local orthonormal frame is given by a Lie bracket generating pair of vector fields that can become collinear. We study the relation…

Differential Geometry · Mathematics 2016-11-25 Andrei Agrachev , Ugo Boscain , Grégoire Charlot , Roberta Ghezzi , Mario Sigalotti

We discover a fundamental exterior differential system of Riemannian geometry; indeed, an intrinsic and invariant global system of differential forms of degree $n$ associated to any given oriented Riemannian manifold $M$ of dimension $n+1$.…

Differential Geometry · Mathematics 2022-11-02 Rui Albuquerque