- #1
Goodver
- 102
- 1
Where one can find a proof of the expectation value of operator expression.
<A> = < Ψ | A | Ψ >
or
<A> = integral( Ψ* A Ψ dx )
Thanks.
<A> = < Ψ | A | Ψ >
or
<A> = integral( Ψ* A Ψ dx )
Thanks.
The expectation value of an operator is a mathematical concept used in quantum mechanics to describe the average value of a physical quantity that can be measured in a system. It is represented by the symbol 〈A〉, where A is the operator.
The expectation value of an operator is calculated by taking the inner product of the state vector with the operator applied to the state vector. It is represented by the equation 〈A〉 = 〈ψ|A|ψ〉, where ψ is the state vector.
The expectation value of an operator is significant because it provides a way to calculate the average value of a physical quantity in a quantum system. It allows us to make predictions about the outcome of measurements and understand the behavior of particles at the quantum level.
The uncertainty of an operator is related to the spread of possible outcomes of a measurement of a physical quantity in a quantum system. The expectation value, on the other hand, represents the average value of that physical quantity. The uncertainty can be calculated using the standard deviation of the measurement outcomes, which is related to the expectation value through the Heisenberg uncertainty principle.
Yes, the expectation value of an operator can change over time as the state of the system evolves. This is because the state vector, and therefore the expectation value, is dependent on time. The change in the expectation value can be described by the time-dependent Schrödinger equation.