# Could black holes be driving the expanding universe (dark energy)?

I would like to start be saying I'm no Physicist.

Anyway, my question is: Could black holes be driving the expanding universe (dark energy)?

When I think of the image that the effect of massive objects have on space/time (gravity) and the so-called curvature it creates, it makes sense to me as far as moons, planets, stars etc.

But what interests me is, what is the extent that a black hole has on space/time curvature?

Rather than stretching space/time down into a well, could the stretching be happening in reverse so to speak? Is it mathematically possible to estimate all the black holes and their sizes and to account for this much stretching/energy?

Okay, I see where my wording has gone wrong to the question I was initially trying to ask. The question was not about the 'curvature' of space/time but rather the 'creating' of space/time with black holes. Kind of like space/time fabric creating/expanding machines. The systems that gravitate towards each other, such as the Milky Way and Andromeda would not seem to be affected or stretched apart due to gravitational forces but everything outside of these gravitational forces would expand away.

Take a sun for instance, it has a finite impact on the curvature of space/time fabric, but take that same sun and make it a black hole and the impact on the curvature of space/time seems different to me at or in the event horizon. Infinite stretching so to speak. With the results of the fabric expanding outward in all directions.

• The gravity of a black hole is completely indistinguishable from the object that it came from at a large distance. If the sun were a black hole with the sun's mass, the orbits of the planets would be essentially the same (minus the absence of minor tidal effects on Mercury or so). In essence, if the effect that you are thinking of did exist, it shouldn't just be tied to black holes but to all matter density. The way dark energy is currently part of general relativity, however, makes it a completely independent quantity of the total mass density. One might think of modified theories, though. Commented Apr 27, 2015 at 3:41
• I left out other matter densities because we know what effect they have on space/time (at the core of a star). There seems to be a finite curvature. However, what has happened to space/time past an event horizon? Is there still a finite curvature there? Commented Apr 27, 2015 at 3:57
• It's not clear what happens on the other side of event horizons, or whether that's even a physically defined volume. Far outside their event horizons, black holes should behave like ordinary matter, though, so it's not obvious how local physics would distinguish whether test masses are being attracted (or repelled) by either a mass of ordinary matter or a black hole. Once we leave standard theory, though, one could imagine adding long distance repellent terms. Did you look at modified theories of gravity, yet? Commented Apr 27, 2015 at 4:19
• It's great to see that so many others have wondered the same thing, and I'm glad you managed to get genuine replies and not rude comments such as "Non-physicists should never ever ask physics questions, go read a book" or just unexplained downvotes Commented Oct 20, 2016 at 14:46
• I've just posted a similar question ("Has a setting in black hole cosmogenesis been considered as an explanation for dark energy?"), based on three papers by Poplawski ("Cosmology with torsion", "Four fermion interaction from torsion as dark energy", and "Non-parametric reconstruction of an inflaton potential"). No straight answer yet, and the "Four fermion" paper's a little too sophisticated for me to put it together solidly with the other two. (I'm not a physicist, either.) You may want to have a look at my question and, especially, at any answer it might get. Commented Feb 3, 2018 at 5:41