Higher dimensional shear-free radiating collapse

2018 ◽  
Vol 96 (11) ◽  
pp. 1201-1204
Author(s):  
Hassan Shah ◽  
Zahid Ahmad ◽  
Suhail Khan

In this paper, shear-free gravitational collapse with heat flux is discussed by considering higher dimensional spherically symmetric space–time as interior metric and higher dimensional Vaidya space–time as exterior metric. The effects of dissipation on collapse are investigated. A simple approximate higher dimensional conformally flat model is proposed that satisfies the junction conditions. Temperature profile of the proposed model is also calculated. It is concluded that dissipation decreases the collapsing rate and temperature profile of the suggested model.

2001 ◽  
Vol 16 (25) ◽  
pp. 1629-1634 ◽  
Author(s):  
SUBENOY CHAKRABORTY ◽  
ANUSUA BAVEJA

Vacuum solutions are obtained in higher-dimensional spherically symmetric space–time with Brans–Dicke theory. Solutions are obtained assuming the metric coefficients to be in separable product form.


Pramana ◽  
1993 ◽  
Vol 40 (3) ◽  
pp. 207-212 ◽  
Author(s):  
Subenoy Chakraborty ◽  
Ashok Kr. Chakraborty

2016 ◽  
Vol 13 (02) ◽  
pp. 1650015 ◽  
Author(s):  
Carlo Alberto Mantica ◽  
Young Jin Suh

In this paper we present some new results about [Formula: see text]-dimensional pseudo-Z symmetric space-times. First we show that if the tensor Z satisfies the Codazzi condition then its rank is one, the space-time is a quasi-Einstein manifold, and the associated 1-form results to be null and recurrent. In the case in which such covector can be rescaled to a covariantly constant we obtain a Brinkmann-wave. Anyway the metric results to be a subclass of the Kundt metric. Next we investigate pseudo-Z symmetric space-times with harmonic conformal curvature tensor: a complete classification of such spaces is obtained. They are necessarily quasi-Einstein and represent a perfect fluid space-time in the case of time-like associated covector; in the case of null associated covector they represent a pure radiation field. Further if the associated covector is locally a gradient we get a Brinkmann-wave space-time for [Formula: see text] and a pp-wave space-time in [Formula: see text]. In all cases an algebraic classification for the Weyl tensor is provided for [Formula: see text] and higher dimensions. Then conformally flat pseudo-Z symmetric space-times are investigated. In the case of null associated covector the space-time reduces to a plane wave and results to be generalized quasi-Einstein. In the case of time-like associated covector we show that under the condition of divergence-free Weyl tensor the space-time admits a proper concircular vector that can be rescaled to a time like vector of concurrent form and is a conformal Killing vector. A recent result then shows that the metric is necessarily a generalized Robertson–Walker space-time. In particular we show that a conformally flat [Formula: see text], [Formula: see text], space-time is conformal to the Robertson–Walker space-time.


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