**Hiroyuki Tomita (Kinki University)**

**Title:** Classical analogue of weak value in stochastic process

**Abstract:**
One of the interesting notions in the recent development
of quantum physics is the weak value related to weak measurements.
We emulate the weak value by two-time conditional expectations
in a simple, classical stochastic model.
We use the well known symmetrized form of the master equation,
which is formally equivalent to the wave equation in quantum
mechanics apart from the fact that time is imaginary and wave
functions are always real.
The origin of the abnormal behaviors such as the negative probability
and the abnormal enhancement of some expectations becomes clearer
in the present case, where the two-time conditional probability
has no ambiguity of imaginary/complex values.