Physics
Scientific paper
Jun 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002phrvd..65l4028b&link_type=abstract
Physical Review D, vol. 65, Issue 12, id. 124028
Physics
1
Relativistic Stars: Structure, Stability, And Oscillations, Stellar Characteristics And Properties
Scientific paper
A well known result of a theorem due to Buchdahl, for a regular fluid sphere with a mass density which does not increase outwards, is that the ratio of its gravitational mass M to the coordinate radius R satisfies the inequality GM/R<=4/9. This restriction arises from the condition that the isotropic pressure does not become infinity at the center of the sphere to prevent collapse. Buchdahl has also derived an inequality for the value of the central pressure of the sphere which we use to show that the minimum value for this pressure corresponds to a fluid of constant density. Then, using these results and the energy condition (\|p(r)\|<=βρ(r)/3), we find new bounds for the mass to radius ratio given by 2GM/R<=S(ξ), where S(ξ) is a nondecreasing function of its argument ξ=βρc/3ρ¯, where ρc is the central density of the star and ρ¯ its mean density. For a constant density star, and β=3 (which corresponds to the dominant energy condition), we have S(1)=3/4, which implies an upper limit for the gravitational redshift factor for light coming from the surface of the star given by z<=1. We reobtain, for a general model and the values β=3, ρc-->∞, Buchdahl's limit; however, a comparison of our results with a previous inequality found by Buchdahl shows that for any values of β and the ratio ρc/ρ¯ our bound of the mass to radius ratio is more strict.
Barraco Daniel
Hamity Victor Hugo
No associations
LandOfFree
Maximum mass of a spherically symmetric isotropic star does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Maximum mass of a spherically symmetric isotropic star, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Maximum mass of a spherically symmetric isotropic star will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1200087