scholarly journals Conformal Ricci Collineations of Static Spherically Symmetric Spacetimes

2008 ◽  
Vol 49 (6) ◽  
pp. 1527-1532 ◽  
Author(s):  
Ugur Camci ◽  
Asghar Qadir ◽  
K Saifullah
2019 ◽  
Vol 9 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Fawad Khan ◽  
Tahir Hussain ◽  
Ashfaque Hussain Bokhari ◽  
Sumaira Saleem Akhtar

Abstract For a perfect fluid matter, we present a study of conformal Ricci collineations (CRCs) of non-static spherically symmetric spacetimes. For non-degenerate Ricci tenor, a vector field generating CRCs is found subject to certain integrability conditions. These conditions are then solved in various cases by imposing certain restrictions on the Ricci tensor components. It is found that non-static spherically symmetric spacetimes admit 5, 6 or 15 CRCs. In the degenerate case, it is concluded that such spacetimes always admit infinite number of CRCs.


2018 ◽  
Vol 33 (34) ◽  
pp. 1850196
Author(s):  
Tahir Hussain ◽  
Sumaira Saleem Akhtar ◽  
Fawad Khan

Non-static spherically symmetric spacetimes with perfect fluid matter are considered and their homothetic Ricci collineations (HRCs) are investigated for degenerate as well as non-degenerate Ricci tensor. The present analysis shows that, for non-degenerate Ricci tensor, the possible number of HRCs admitted by these spacetimes is 5, 6 or 7, while they possess 4, 11 or otherwise infinite number of HRCs when the Ricci tensor is degenerate.


2013 ◽  
Vol 52 (10) ◽  
pp. 3534-3542 ◽  
Author(s):  
Ashfaque H. Bokhari ◽  
A. G. Johnpillai ◽  
A. H. Kara ◽  
F. M. Mahomed ◽  
F. D. Zaman

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Anslyn J. John ◽  
Chris Z. Stevens

AbstractThe Johannsen–Psaltis spacetime explicitly violates the no-hair theorem. It describes rotating black holes with scalar hair in the form of parametric deviations from the Kerr metric. In principle, black hole solutions in any modified theory of gravity could be written in terms of the Johannsen–Psaltis metric. We study the accretion of gas onto a static limit of this spacetime. We utilise a recently proposed pseudo–Newtonian formulation of the dynamics around arbitrary static, spherically symmetric spacetimes. We obtain a potential that generalises the Paczyński–Wiita potential to the static Johannsen–Psaltis metric. We also perform a fully relativistic analysis of the geodesic equations in the static Johannsen–Psaltis spacetime. We find that positive (negative) values of the scalar hair parameter, $$\epsilon _{3}$$ϵ3, lower (raise) the accretion rate. Similarly, positive (negative) values of $$\epsilon _{3}$$ϵ3 reduce (increase) the gravitational acceleration of radially infalling massive particles.


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