PubMed Health⌕ Search

Biomedical subjects

Roy Maartens

Publications and source records attributed to Roy Maartens.

2 recordsLinked to original sources

Black hole mass threshold from nonsingular quantum gravitational collapse.

Quantum gravity is expected to remove the classical singularity that arises as the end state of gravitational collapse. To investigate this, we work with a toy model of a collapsing homogeneous scalar field. We show that nonperturbative semiclassical effects of loop quantum gravity cause a bounce and remove the black hole singularity. Furthermore, we find a critical threshold scale below which no horizon forms: quantum gravity may exclude very small astrophysical black holes.

Journal Article↗

Detecting extra dimensions with gravity-wave spectroscopy: the black-string brane world.

Using the black string between two branes as a model of a brane-world black hole, we compute the gravity-wave perturbations and identify the features arising from the additional polarizations of the graviton. The standard four-dimensional gravitational wave signal acquires late-time oscillations due to massive modes of the graviton. The Fourier transform of these oscillations shows a series of spikes associated with the masses of the Kaluza-Klein modes, providing in principle a spectroscopic signature of extra dimensions.

Journal Article↗