Hello all, I will be learning about the path integral formulation, among other topics, in an advanced QM class during this upcoming semester, so I read ahead a little. I understand that, essentially, the propagator between two points in spacetime is the normalized sum of exp(i*2pi*S/h) over all spacetime paths connecting the points, where S is the action of the path. I became curious if there is a way of assigning a probability amplitude to paths in spacetime; in effect, finding an expression that says which paths are more likely than others, similar to the way the Schrodinger equation says which positions of a particle are more likely. My textbook seemed silent on this point, and I think it is a theoretically interesting question. Thanks!