Chaotic dynamics around astrophysical objects with nonisotropic stresses
- Escuela de Fisica, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia) and Departamento de Fisica, Universidad Nacional de Colombia, Santa fe de Bogota D.C. (Colombia)
The existence of chaotic behavior for the geodesics of the test particles orbiting compact objects is a subject of much current research. Some years ago, Gueron and Letelier [Phys. Rev. E 66, 046611 (2002)] reported the existence of chaotic behavior for the geodesics of the test particles orbiting compact objects like black holes induced by specific values of the quadrupolar deformation of the source using as models the Erez--Rosen solution and the Kerr black hole deformed by an internal multipole term. In this work, we are interested in the study of the dynamic behavior of geodesics around astrophysical objects with intrinsic quadrupolar deformation or nonisotropic stresses, which induces nonvanishing quadrupolar deformation for the nonrotating limit. For our purpose, we use the Tomimatsu-Sato spacetime [Phys. Rev. Lett. 29 1344 (1972)] and its arbitrary deformed generalization obtained as the particular vacuum case of the five parametric solution of Manko et al. [Phys. Rev. D 62, 044048 (2000)] characterizing the geodesic dynamics throughout the Poincare sections method. We found only regular motion for the geodesics in the Tomimatsu-Sato {delta}=2 solution. Additionally, using the deformed generalization of Tomimatsu-Sato {delta}=2 solution given by Manko et al. we found chaotic motion for oblate deformation instead of prolate deformation, which is in contrast to the results by Gueron and Letelier. It opens the possibility that the particles forming the accretion disk around a large variety of different astrophysical bodies (nonprolate, e.g., neutron stars) could exhibit chaotic dynamics. We also conjecture that the existence of an arbitrary deformation parameter is necessary for the existence of chaotic dynamics.
- OSTI ID:
- 20935203
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 75, Issue 2; Other Information: DOI: 10.1103/PhysRevD.75.023008; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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