Recent content by SFXMan

Incidentally, in low-dimensional cases, these plasmons afford us a nice description when the Fermi liquid renormalisation scheme stops working, as a highly correlated 1D electron liquid can be described as a gas of non-interacting plasmons.

Can't we just construct histories in either picture and assign them probabilities (provided certain consistency conditions are met)? Each possible history would then represent a possible stochastic evolution of our system, no?

Ok I think I better understand what you are looking for. The nonunitary evolution I suggested earlier actually describes a sequence of probabilistic measurement outcomes, rather than just the outcome ##o_j##, and so it is not just a description of ##o_j##.

I might be misunderstanding the problem but: In the Schroedinger picture, we would handle uncertainty about whether a measurement has occurred by replacing a sharp wavefunction collapse with a nonunitary time-evolution into a mixed state. In the Heisenberg picture, we would presumably apply the...

Insofar as the quantum time-evolution of the microstate is a more complete description than the approximately classical time-evolution of the macrostate, yes.

Wouldn't we just stochastically evolve our operator? Consider the operator $$|o_j,t_0\rangle\langle o_j,t_0|$$ If we are interested in the likelihood of measuring ##o_j## at time ##t_2##, we would evolve our operator using normal unitary time-evolution $$U_{t_0\rightarrow t_2}$$ But if we wanted...