Compactified and reduced dynamics for locally rotationally symmetric Bianchi type IX perfect fluid models

1990 ◽  
Vol 7 (8) ◽  
pp. 1365-1385 ◽  
Author(s):  
C Uggla ◽  
H Zur-Muhlen
1986 ◽  
Vol 18 (1) ◽  
pp. 79-91 ◽  
Author(s):  
B. K. Nayak ◽  
G. B. Bhuyan

2020 ◽  
Vol 35 (20) ◽  
pp. 2050169
Author(s):  
Amjad Mahmood ◽  
Ahmad T. Ali ◽  
Suhail Khan

The purpose of this paper is to explore concircular vector fields (CVFs) of locally rotationally symmetric (LRS) Bianchi type-V spacetimes and to investigate whether these CVFs are Ricci soliton vector fields. We first obtained the concircular equations and then solved them by integrating directly. The existence of concircular symmetry imposes restrictions on the metric functions. It is shown that Bianchi type-V spacetimes admit four-, five-, six-, seven-, eight- or fifteen-dimensional CVFs. Further, we studied the Ricci soliton vector fields for all the cases where Bianchi type-V spacetimes admit CVFs. For this purpose, the obtained CVFs are substituted into Ricci soliton equations. These equations imposed further restrictions on metric functions and it is shown in each case that either all or some CVFs are also Ricci soliton vector fields. The gradient of Ricci soliton vector fields are also obtained. It is shown that the metrics that admit CVFs represent physically plausible perfect fluid models under certain conditions.


1997 ◽  
Vol 38 (5) ◽  
pp. 2611-2615 ◽  
Author(s):  
Ulf S. Nilsson ◽  
Claes Uggla

2019 ◽  
Vol 34 (36) ◽  
pp. 1975003
Author(s):  
Ashfaque H. Bokhari ◽  
A. H. Kara ◽  
B. Gadjagboui

We undertake a detailed analysis of the symmetry structures of the plane symmetric and the locally rotationally symmetric (LRS) Bianchi type I spacetimes in the [Formula: see text] gravity. In particular, we construct all the variational symmetries associated with its Lagrangian and, in some cases, construct the associated conservation laws using Noether’s theorem. Giving a comparison between isometries and variational symmetries, we give symmetry structures of some well-known spacetimes.


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