Results 61 to 70 of about 342 (113)

On the uniqueness of a shear-vorticity-acceleration-free velocity field in space-times [PDF]

, 2019
We prove that in space-times a velocity field that is shear, vorticity and acceleration-free, if any, is unique up to reflection, with these exceptions: generalized Robertson-Walker space-times whose space sub-manifold is warped, and twisted space-times (
Mantica, Carlo Alberto, Molinari, Luca Guido, Tacchini, Adriano   +2 more
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Hyperbolic Ricci solitons on perfect fluid spacetimes [PDF]

In the present paper, we investigate perfect fluid spacetimes and perfect fluid generalized Roberston-Walker spacetimes that contain a torse-forming vector field satisfying almost hyperbolic Ricci solitons.
Abdul Haseeb, Mehdi Jafari, Nargis Jamal, Shahroud Azami   +3 more
core   +1 more source

ON RICCI SOLITONS AND SUBMANIFOLDS WITH A SEMI-SYMMETRIC NON-METRIC CONNECTION [PDF]

We consider Ricci solitons with a semi-symmetric non-metric connection. We find some properties, when the potential vector field is torse-forming.
Doğru, Yusuf
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Perfect Fluid Spacetimes Admitting Almost Riemann Solitons

Axioms
In this investigation, we examine the geometric character of almost Riemann solitons and gradient almost Riemann solitons in the context of perfect fluid solutions of the Einstein equations that admit a torse-forming vector field ζ.
Mehdi Jafari, Shahroud Azami
doaj   +1 more source

The geometric Cauchy problem for developable submanifolds

, 2019
Given a smooth distribution $\mathscr{D}$ of $m$-dimensional planes along a smooth regular curve $\gamma$ in $\mathbb{R}^{m+n}$, we consider the following problem: To find an $m$-dimensional developable submanifold of $\mathbb{R}^{m+n}$, that is, a ruled
Raffaelli, Matteo
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Natural PDE's of Linear Fractional Weingarten surfaces in Euclidean Space [PDF]

, 2012
We prove that the natural principal parameters on a given Weingarten surface are also natural principal parameters for the parallel surfaces of the given one. As a consequence of this result we obtain that the natural PDE of any Weingarten surface is the
Ganchev, Georgi, Mihova, Vesselka
core  

On pseudosymmetric manifolds

, 2015
In the literature, there are two different notions of pseudosymmetric manifolds, one by Chaki [7] and other by Deszcz [16], and there are many papers related to these notions.
Deszcz, Ryszard, Hotlos, Marin, Jelwicki, Jan, Kundu, Haradhan, Shaikh, Absos Ali   +4 more
core   +1 more source

Ricci–Bourguignon Almost Solitons with Vertical Torse-Forming Potential on Almost Contact Complex Riemannian Manifolds

Mathematics
Almost contact complex Riemannian manifolds, also known as almost contact B-metric manifolds, are equipped with Ricci–Bourguignon-like almost solitons.
Mancho Manev
doaj   +1 more source

On Decomposable Almost Pseudo Conharmonically Symmetric Manifolds [PDF]

, 2012
summary:The object of the present paper is to study decomposable almost pseudo conharmonically symmetric ...
Yilmaz, Hülya Bağdatlı
core   +1 more source

SOME RESULTS ON YAMABE SOLITONS ON NEARLY HYPERBOLIC SASAKIAN MANIFOLDS [PDF]

We classify almost Yamabe on nearly hyperbolic Sasakian manifolds whose potential vector field is torse-forming admitting semi-symmetric metric connection and quarter symmetric non-metric connection. Certain results of such solitons on CR-submanifolds of
Siddiqi, Mohd. Danish, Suthar, D. L., Yadav, Sunil Kumar   +2 more
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