Results 11 to 20 of about 567 (106)

A New Class of Almost Ricci Solitons and Their Physical Interpretation. [PDF]

Int Sch Res Notices, 2016
We establish a link between a connection symmetry, called conformal collineation, and almost Ricci soliton (in particular Ricci soliton) in reducible Ricci symmetric semi‐Riemannian manifolds. As a physical application, by investigating the kinematic and dynamic properties of almost Ricci soliton manifolds, we present a physical model of imperfect ...
Duggal KL.
europepmc   +2 more sources

The threat of an indigenous medicinal plant encroacher: Artemisia afra in Klipriviersberg Nature Reserve, Johannesburg, South Africa

African Journal of Ecology, Volume 60, Issue 4, Page 1133-1142, December 2022., 2022
Abstract Artemisia afra was identified as an encroaching shrub in the Klipriviersberg Nature Reserve (KNR). Ecological factors that influence the encroachment of A. afra and its population structure were unknown, making it difficult to monitor and control the spread of the plant.
Kgalalelo T. A. Setshedi, Solomon W. Newete, Ed T. F. Witkowski   +2 more
wiley   +1 more source

ρ‐Einstein Solitons on Warped Product Manifolds and Applications

Journal of Mathematics, Volume 2022, Issue 1, 2022., 2022
The purpose of this research is to investigate how a ρ‐Einstein soliton structure on a warped product manifold affects its base and fiber factor manifolds. Firstly, the pertinent properties of ρ‐Einstein solitons are provided. Secondly, numerous necessary and sufficient conditions of a ρ‐Einstein soliton warped product manifold to make its factor ρ ...
Nasser Bin Turki, Sameh Shenawy, H. K. EL-Sayied, N. Syied, C. A. Mantica, Antonio Masiello   +5 more
wiley   +1 more source

Conformally Flat Pseudoprojective Symmetric Spacetimes in fR,G Gravity

Advances in Mathematical Physics, Volume 2022, Issue 1, 2022., 2022
Sufficient conditions on a pseudoprojective symmetric spacetime (PPS)n whose Ricci tensor is of Codazzi type to be either a perfect fluid or Einstein spacetime are given. Also, it is shown that a (PPS)n is Einstein if its Ricci tensor is cyclic parallel. Next, we illustrate that a conformally flat (PPS)n spacetime is of constant curvature.
Uday Chand De, Sameh Shenawy, Abdallah Abdelhameed Syied, Nasser Bin Turki, Sergey Shmarev   +4 more
wiley   +1 more source

Design Optimization of an Integrated E‐Type Multilink Suspension Wheel‐Side Drive System and Improvement of Vehicle Ride Comfort

Shock and Vibration, Volume 2021, Issue 1, 2021., 2021
Distributed‐drive electric vehicles constitute an important research direction for the future development of electric vehicles. In this regard, the integrated suspension wheel‐side drive system has considerable development potential because it can address the lack of driving smoothness and the grounding deterioration caused by the excessive unsprung ...
Wen Lu, Wenbo Li, Xinbo Chen, Mohamed A. A. Abdelkareem   +3 more
wiley   +1 more source

Certain Class of Almost α‐Cosymplectic Manifolds

Journal of Mathematics, Volume 2021, Issue 1, 2021., 2021
This paper concerned with almost α‐cosymplectic manifolds satisfying conformally flat condition. Firstly, we investigate Kaehler integral submanifolds of almost α‐cosymplectic manifolds. Next, we study conformally flat almost α‐cosymplectic manifolds of dim ≥ 5 whose integral submanifolds are Kaehler.
Sermin Öztürk, Hakan Öztürk, Carmelo Antonio Finocchiaro   +2 more
wiley   +1 more source

Approximate Lie Symmetry Conditions of Autoparallels and Geodesics

Abstract and Applied Analysis, Volume 2020, Issue 1, 2020., 2020
This paper is devoted to the study of approximate Lie point symmetries of general autoparallel systems. The significance of such systems is that they characterize the equations of motion of a Riemannian space under an affine parametrization. In particular, we formulate the first‐order symmetry determining equations based on geometric requirements and ...
Sameerah Jamal, Shi Liang Wu
wiley   +1 more source

PROPER CURVATURE COLLINEATIONS IN NONSTATIC SPHERICALLY SYMMETRIC SPACE–TIMES [PDF]

International Journal of Modern Physics A, 2008
A study of nonstatic spherically symmetric space–times according to their proper curvature collineations is given by using the rank of the 6×6 Riemann matrix and direct integration techniques. Studying proper curvature collineations in each case of the above space–times it is shown that when the above space–times admit proper curvature collineations ...
Shabbir, Ghulam, Ramzan, M.
openaire   +1 more source

Matter collineations of Spacetime Homogeneous G\"odel-type Metrics [PDF]

, 2003
The spacetime homogeneous G\"odel-type spacetimes which have four classes of metrics are studied according to their matter collineations. The obtained results are compared with Killing vectors and Ricci collineations.
Ahsan Z, Ahsan Z, Banerjee A, Bokhari A H, Calvão M O, Camci U, Camci U, Carot J, Carot J, Coley A A, Collinson C D, Davis W R, Gödel K, Hall G S, Hall G S, Katzin G H, M Sharif, Melfo A, Núbar nez L, Raychaudhuri A K, Rebouças M J, Rebouças M J, Rebouças M J, Rebouças M J, Sharif M, Sharif M, Sharif M, Som M M, Teixeira A F F, Tsamparlis M, U Camci, Yavuz dot I   +31 more
core   +3 more sources

Homotheties of a Class of Spherically Symmetric Space‐Time Admitting G3 as Maximal Isometry Group

Advances in Mathematical Physics, Volume 2018, Issue 1, 2018., 2018
The homotheties of spherically symmetric space‐time admitting G4, G6, and G10 as maximal isometry groups are already known, whereas, for the space‐time admitting G3 as isometry groups, the solution in the form of differential constraints on metric coefficients requires further classification. For a class of spherically symmetric space‐time admitting G3
Daud Ahmad, Kashif Habib, Kaliyaperumal Nakkeeran   +2 more
wiley   +1 more source