A black hole cosmology is a cosmological model in which the observable universe is the interior of a black hole. Such models were originally proposed by theoretical physicist Raj Pathria, and concurrently by mathematician I. J. Good.

Any such model requires that the Hubble radius of the observable universe be equal to its Schwarzschild radius, that is, the product of its mass and the Schwarzschild proportionality constant. This is indeed known to be nearly the case; however, most cosmologists consider this close match a coincidence.

In the version as originally proposed by Pathria and Good, and studied more recently by, among others, Nikodem Popławski, the observable universe is the interior of a black hole existing as one of possibly many inside a larger parent universe, or multiverse.

Read more