Results 41 to 50 of about 313 (89)

On a class of exact locally conformal cosymlectic manifolds

International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 2, Page 267-278, 1996., 1994
An almost cosymplectic manifold M is a (2m + 1)‐dimensional oriented Riemannian manifold endowed with a 2‐form Ω of rank 2m, a 1‐form η such that Ωm Λ η ≠ 0 and a vector field ξ satisfying iξΩ = 0 and η(ξ) = 1. Particular cases were considered in [3] and [6].
I. Mihai, L. Verstraelen, R. Rosca
wiley   +1 more source

On the Potential Vector Fields of Soliton-Type Equations

Axioms
We highlight some properties of a class of distinguished vector fields associated to a (1,1)-tensor field and to an affine connection on a Riemannian manifold, with a special view towards the Ricci vector fields, and we characterize them with respect to ...
Adara M. Blaga
doaj   +1 more source

Ricci‐Bourguignon Solitons With Certain Applications to Relativity

Journal of Mathematics, Volume 2025, Issue 1, 2025.
This article concerns with the investigation of Ricci‐Bourguignon solitons and gradient Ricci‐Bourguignon solitons in perfect fluid space‐times and generalised Robertson–Walker space‐times. First, we deduce the criterion for which the Ricci‐Bourguignon soliton in a perfect fluid space‐time is steady, expanding or shrinking. Then, we establish that if a
Krishnendu De, Mohammad Nazrul Islam Khan, Uday Chand De, Yanlin Li, Pramita Mishra   +4 more
wiley   +1 more source

On the Invariant Theory of Weingarten Surfaces in Euclidean Space

, 2008
We prove that any strongly regular Weingarten surface in Euclidean space carries locally geometric principal parameters. The basic theorem states that any strongly regular Weingarten surface is determined up to a motion by its structural functions and ...
Baran H, Baran H Marvan M, Bonnet O, Bonnet O, Bryant R, Eisenhart L, Enneper A, Enneper A, Enneper A, Finkel F, Georgi Ganchev, Gray A, Kenmotsu K, Kruppa E, Serret J, Sturm C, Sturm C, Sturm C, Vesselka Mihova, von Lilienthal R   +19 more
core   +2 more sources

η-Ricci solitons in (ε)-almost paracontact metric manifolds [PDF]

, 2018
The object of this paper is to study η -Ricci solitons on ( ε ) -almost paracontact metric manifolds. We investigate η -Ricci solitons in the case when its potential vector field is exactly the characteristic vector field ξ of the ( ε ) -almost ...
Adara Monica Blaga, Bilal Eftal Acet, Feyza Esra Erdoğan, Selcen Yüksel Perktaş   +3 more
core   +2 more sources

Geometric Classifications of Perfect Fluid Space‐Time Admit Conformal Ricci‐Bourguignon Solitons

Journal of Mathematics, Volume 2024, Issue 1, 2024.
This paper is dedicated to the study of the geometric composition of a perfect fluid space‐time with a conformal Ricci‐Bourguignon soliton, which is the extended version of the soliton to the Ricci‐Bourguignon flow. Here, we have delineated the conditions for conformal Ricci‐Bourguignon soliton to be expanding, steady, or shrinking.
Noura Alhouiti, Soumendu Roy, Santu Dey, Fatemah Mofarreh, Akram Ali, Yanlin Li, Francisco J. Garcia-Pacheco   +6 more
wiley   +1 more source

The Z‐Tensor on Almost Co‐Kählerian Manifolds Admitting Riemann Soliton Structure

Advances in Mathematical Physics, Volume 2024, Issue 1, 2024.
A Riemann soliton (RS) is a natural generalization of a Ricci soliton structure on pseudo‐Riemannian manifolds. This work aims at investigating almost co‐Kählerian manifolds (ACKM) 2n+1 whose metrics are Riemann solitons utilizing the properties of the Z‐tensor.
Sunil Kumar Yadav, Sameh Shenawy, Nasser Bin Turki, Rajendra Prasad, Mohammad Mirzazadeh   +4 more
wiley   +1 more source

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
core   +1 more source

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
core   +2 more sources