3 ms·
I'm surely missing something in the paper, but I'm having a hard time seeing how the fact that black holes gain mass in a way that is seemingly coupled with the
by dmbche 4y ago
I'm surely missing something in the paper, but I'm having a hard time seeing how the fact that black holes gain mass in a way that is seemingly coupled with the rate of expansion of the universe mean that it's driving the expansion - couldn't the universe just be expanding, giving the black holes the energy they would need to get this large?
Super interesting papers!
- leereeves 4y agoUnfortunately the article seems to gloss over that point with just one sentence: > The conclusion is profound: Croker and Weiner had already shown that if k is 3, then all black holes in the universe collectively contribute a nearly constant dark energy density, just like measurements of dark energy suggest. That sentence contains a link to a paper[1] that's highly technical and beyond my understanding of physics, but concludes: > A population of such stellar-collapse remnants can shift in energy $\propto a^3$ while diluting in number density $\propto 1/{a}^{3}$. The population-averaged energy density is then effectively constant and readily produces the observed ${{\rm{\Omega }}}_{{\rm{\Lambda }}}$. which matches the claim in the article. But to understand why, I guess we'd have to learn general relativity to understand the math in that paper. 1: https://iopscience.iop.org/article/10.3847/1538-4357/ab32da#apjab32das5 https://iopscience.iop.org/article/10.3847/1538-4357/ab32da#...