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- Bradley, Michael, et al.
(author)
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Quadrupole moment of slowly rotating fluid balls
- 2009
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In: Physical Review D. Particles and fields. - 0556-2821 .- 1089-4918. ; 79:4, s. 044018-1-044018-13
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Journal article (peer-reviewed)abstract
- In this paper we use the second order formalism of Hartle to study slowly and rigidly rotating stars with focus on the quadrupole moment of the object. The second order field equations for the interior fluid are solved numerically for different classes of possible equations of state and these solutions are then matched to a vacuum solution that includes the general asymptotically flat axisymmetric metric to second order, using the Darmois-Israel procedure. For these solutions we find that the quadrupole moment differs from that of the Kerr metric, as has also been found for some equations of state in other studies. Further we consider the post-Minkowskian limit analytically. In the paper we also illustrate how the relativistic multipole moments can be calculated from a complex gravitational potential.
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- Bradley, Michael, et al.
(author)
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Slowly rotating fluid balls of Petrov type D
- 2007
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In: Physical Review D. Particles and fields. - 0556-2821 .- 1089-4918. ; 75:2, s. 024013-024026
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Journal article (peer-reviewed)abstract
- The second order perturbative field equations for slowly and rigidly rotating perfect fluid balls of Petrov type D are solved numerically. It is found that all the slowly and rigidly rotating perfect fluid balls up to second order, irrespective of Petrov type, may be matched to a possibly nonasymptotically flat stationary axisymmetric vacuum exterior. The Petrov type D interior solutions are characterized by five integration constants, corresponding to density and pressure of the zeroth order configuration, the magnitude of the vorticity, one more second order constant, and an independent spherically symmetric second order small perturbation of the central pressure. A four-dimensional subspace of this five-dimensional parameter space is identified for which the solutions can be matched to an asymptotically flat exterior vacuum region. Hence these solutions are completely determined by the spherical configuration and the magnitude of the vorticity. The physical properties, like equation of state, shape, and speed of sound, are determined for a number of solutions.
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- Bradley, Michael, et al.
(author)
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The quadrupole moment of slowly rotating stars
- 2012
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In: Proceedings of the twelfth Marcel Grossman meeting on general relativity. - Singapore : World Scientific. - 9789814374514 - 9789814458030 ; , s. 1883-1886
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Conference paper (peer-reviewed)abstract
- The second order field equations for slowly and rigidly rotating stars are solved numerically for different possible equations of state and these solutions are then matched to the general asymptotically flat axisymmetric vacuum metric to second order in the rotational parameter. For these solutions we find that the quadrupole moment differs from that of the Kerr metric. Further we consider the post-Minkowskian limit analytically.
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6. |
- Bradley, Michael, et al.
(author)
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The quadrupole moment of slowly rotating stars
- 2010
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In: Journal of Physics: Conference Series. - : IOPScience. - 1742-6596.
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Conference paper (peer-reviewed)abstract
- The second order field equations for the interior of slowly and rigidly rotating stars are solved numerically for different classes of possible equations of state and these solutions are then matched to the general asymptotically flat axisymmetric vacuum metric to second order in the rotational parameter. For these solutions we find that the quadrupole moment differs from that of the Kerr metric. Further we consider the post-Minkowskian limit analytically.
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