Time symmetry in wave function collapse

Understand

The notion of a physical collapse of the wave function is embodied in dynamical collapse models.

• These involve a modification of the unitary evolution of the wave function such as to give a dynamical account of collapse.
• The resulting dynamics is at first sight time asymmetric for the simple reason that the wave function depends on those collapse events in the past but not those in the future.
• Here we show that dynamical wave function collapse models admit a general description that has no inbuilt direction of time.