Can dark energy or dark matter affect black holes I was wondering if black holes are the greatest force of gravity how does other highly spoken about concepts such as dark energy or dark matter compare. Can a black hole absorb dark energy or dark matter? I though dark matter held galaxies together. If a black hole could absorb the dark matter would that be a problem: i.e. the universe getting smaller?
Dark matter can, and probably does, fall into black holes and affects them just as any other form of matter or energy falling into them does. It doesn't fall in a huge amount because, like anything else approaching a black hole it usually isn't aimed straight in, but rather misses a bit and swings by and escapes again. Unlike normal matter, dark matter experiences almost no friction or collisions from other stuff near the black hole (it goes straight through everything, including itself, we think) so it doesn't get caught in the accretion disk or anything. Dark matter falling into the central SMBH doesn't do much to galaxy, because its mass is still there pulling on the stars and so on just as it did before it fell in.

Dark energy is another story. In most of the various competing theories in which it exists, it is an energy inherent in space. Every cubic meter of space contains a certain (small) amount of dark energy, which can't move around or anything. It shows up as something like a pressure, causing space to tend to expand whenever there isn't a larger force (like the gravity of nearby masses) causing it to contract.