# ASTRODEBATA / Ema Mlinar: Possible cosmological coupling of black holes

**Possible cosmological coupling of black holes**

*Ema Mlinar
(Fakulteta za matematiko in fiziko)*

Besides some well-established solutions for black holes, there exist many alternative ones. In the last years, a model of a black hole with a dark energy interior became popular. The mass of these black holes can couple to the cosmological scale factor, which means that the black hole would grow with time. If the model is correct, such black holes would suffice to account for all of the dark energy in the universe. In this talk I focus on observational tests of this hypothesis using supermassive black holes as well as stellar-mass ones. There is a lot of data for masses of supermassive black holes at different redshifts, which enables us to track their evolution with the scale factor. On the other hand, this is not possible for stellar-mass black holes. We can instead use X-ray binaries containing a black hole, where we ultimately use the age and the mass of the black hole to determine the coupling parameter.