Is the wave function of quantum mechanics considered to be the quint-essential invariant object? Is it the wave function that must not change with space, time, gravitational field, etc? It would seem to me that the relative probabilities that things happen is the thing that can not change with perspective (space or time, etc). But I am challenged by considering Hawking radiation and Unruh radiation, where things happen at all only for accelerated observers. This would tell me (if I'm understanding it correctly) that even relative probabilities change for different observers. Or is it that these types of radiation always take place, and the relative probability of what kinds of particles are more likely to appear is still the same only more frequent with time for some observers?