Inverted equation of state and general approach to vacuum-like configurations
arXiv:2509.00899
Abstract
We consider spherically symmetric static black hole configurations that obey the vacuum equation of state: , where is the radial pressure, being energy density. We find in a closed form the metric for an arbitrary equation of state for tangential pressure . The corresponding formulas enable us to embrace compact Schwarzschild-like configurations and dispersed systems. They include metrics with a regular center and singular ones. In a particular case, the metric of the Kiselev black hole is reproduced.
10 pages. Matches published version including new title