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The Effects of Shear and Rotation Anisotropy Upon the Process of Gravitational Instability

A. Del Popolo·E. N. Ercan·M. Gambera
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Abstract

In this paper, we study the role of shear fields on the evolution of density perturbations embedded in a Friedmann flat background universe, by studying the evolution of a homogeneous ellipsoid model. In this context, we show that while the effect of the shear is that of increasing the growth rate of the density contrast of a mass element, the angular momentum acquired by the ellipsoid has the right magnitude to counterbalance the shear. Finally, our result show that initial asphericities and tidal interaction induce a slowing down of the collapse after the system has broken away from the general expansion, in perfect agreement with the previrialization conjecture (Peebles & Groth 1976; Davis & Peebles 1977).

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A. Del Popolo, E. N. Ercan, M. Gambera. 2002-08-19. The Effects of Shear and Rotation Anisotropy Upon the Process of Gravitational Instability. https://doi.org/10.1515/astro-2001-0407

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