Adding antimatter to a matter black hole (don't think it matters actually, but this seems to be the case in question) should increase the mass and size, not decrease.
Correct, the photons produced from annihilation should match the inputs.
To decrease you'd need to add negative mass or negative energy, which aren't things we've found to exist yet.
We don't actually know _what_ will happen in the singularity of a black hole, to answer the question of if annihilation will happen there. As far as I know we don't have any model of what happens in a singularity.
Correct, the photons produced from annihilation should match the inputs.
To decrease you'd need to add negative mass or negative energy, which aren't things we've found to exist yet.
We don't actually know _what_ will happen in the singularity of a black hole, to answer the question of if annihilation will happen there. As far as I know we don't have any model of what happens in a singularity.