[pointlessone]

I thought infalling matter radiates because of friction in accretion disc. Does a similar structure form in a much denser interior of a star?

[pdonis]

Matter falling into a spinning black hole surrounded mostly by vacuum forms an accretion disc. But friction and heating and radiation will occur in infalling matter no matter how it is falling in. A black hole inside a star would probably not just have an accretion disc, it would have accretion happening in all directions. But the accretion would still involve friction and heating and radiation.

[hinkley]

Would there be a disk at the center of a star? Not a lot of angular momentum there.