Incoming links: Expectation value
One dimension in position representation:
In three dimensions In position representation, we define it by using the gradient, and so we see that
Position and Momentum from Wavefunctions by Faculty of Khan (2018)
Source. Proves in detail why the momentum operator is . The starting point is determining the time derivative of the expectation value of the position operator.TODO what it means to solve an Ising model in general?
stanford.edu/~jeffjar/statmech/lec4.html gives some good notions:
- is the expectation value of the value. It is therefore a number between -1.0 an and 1.0, -1.0 means everything is always down, 0.0 means half up half down, and 1.0 means all up
- : correlation between neighboring states. TODO.