Spherical symmetric dust collapse in a Vector-Tensor gravity

Abstract

There is a viable vector-tensor gravity (VTG) theory, whose vector field produces repulsive forces leading to important effects. In the background universe, the effect of these forces is an accelerated expansion identical to that produced by vacuum energy (cosmological constant). Here, we prove that another of these effects arises for great enough collapsing masses which lead to Schwarzschild black holes and singularities in general relativity (GR). For these masses, pressure becomes negligible against gravitational attraction and the complete collapse cannot be stopped in the context of GR; however, in VTG, a strong gravitational repulsion could stop the falling of the shells towards the symmetry center. A certain study of a collapsing dust cloud is then developed and, in order to undertake this task, the VTG equations in comoving coordinates are written. In this sense and, as it happens in general relativity for a pressureless dust ball, three different solutions are found. These three situations are analyzed and the problem of the shell crossings is approached. The apparent horizons and trapped surfaces, whose analysis will lead to diverse situations, depending on certain theory characteristic parameter value, are also examined.

arXiv comment22 pages, 1 table

References in corpus (14)

• The Confrontation between General Relativity and Experiment
• Masses, Radii, and Equation of State of Neutron Stars
• Black Holes
• A New Open-Source Code for Spherically-Symmetric Stellar Collapse to Neutron Stars and Black Holes
• Relativistic Structure, Stability and Gravitational Collapse of Charged Neutron Stars
• Numerical simulations of stellar collapse in scalar-tensor theories of gravity
• Shell crossing in generalized Tolman-Bondi spacetimes
• Avoidance of singularities in spherically symmetric charged dust
• Numeric simulation of relativistic stellar core collapse and the formation of Reissner-Nordstrom space-times
• Cosmological perturbations in extended electromagnetism. General gauge invariant approach
• Cosmology in a certain vector-tensor theory of gravitation
• More about a successful vector-tensor theory of gravitation
• On the horizons in a viable vector-tensor theory of gravitation
• The charged dust solution of Ruban -- matching to Reissner--Nordström and shell crossings

Cited by in corpus (1)

• Vector Field Dynamics: Field Equations and Energy Tensor