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arXiv · 2604.23592

Gravitational Collapse of an Inhomogeneous Fluid in Rastall Theory

Akbar Jahan·Naser Sadeghnezhad·Amir Hadi Ziaie
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Abstract

We study spherically symmetric gravitational collapse of an inhomogeneous fluid with anisotropic energy momentum tensor (EMT) in Rastall gravity. Considering a linear equation of state (EoS) for the fluid profiles, i.e., $p_r=w_r\rho$ and $p_\theta=w_\theta\rho$, we try to build and investigate non-singular collapse scenarios for which, the spacetime singularity that appears in the homogeneous case~\cite{ahz2019}, is absent. We therefore set the Rastall parameter in such a way that the effective radial pressure vanishes. This helps us to obtain a class of exact nonsingular solutions in which the matter shells undergo a {collapse} process in a contracting regime, reach a bounce point, and then enter an expanding phase. We further investigate formation of trapped surfaces during the dynamical evolution of the collapsing body. {It is found} that for the obtained solutions, {the} trapped surface formation can be avoided and consequently, the bounce event is not covered by the apparent horizon. Validity of weak energy condition (WEC) is also examined for the obtained solutions.

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Akbar Jahan, Naser Sadeghnezhad, Amir Hadi Ziaie. 2026-04-26. Gravitational Collapse of an Inhomogeneous Fluid in Rastall Theory. https://doi.org/10.1007/s12648-025-03759-x

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