My basic understanding of the Unruh effect is that an accelerating observer will experience black-body radiation proportional to the magnitude of the local acceleration, while an observer in an inertial frame will not.
If A is in an inertial frame and observes B in an accelerated frame, A must observe the effect of Unruh radiation on B?
For example B could transmit a signal at A, the increased temperature in B's reference relative to A would cause additional thermal noise in the signal. I have assumed this is true.
If A observed B falling into a gravitational well and hence being accelerated from A's perspective, would A observe the effects of Unruh radiation on B? I have assumed this to be true.
As the acceleration at the singularity of a black-hole is infinite, is it true that any path approaching it will pass through a region where the magnitude of the acceleration is high enough to cause the Unruh radiation to thermalise everything, as the temperature can get arbitrarily high? If B was falling into a black hole, would A observe this 'Unruh thermalisation'?