My first thought is to look at matrix representations.Getterdog said:Summary:: Sum and product of Dirac operators
Looking at. <psi|AB|theta>, under what conditions would this be equal to <psi|A|theta> * <psi|B|theta> I’m just getting into perturbation theory
and am running into confusing notation. Thanks john
Perturbation theory is a mathematical method used to approximate solutions to complex problems by breaking them down into simpler, more manageable parts. It involves introducing a small parameter (known as the perturbation parameter) into the equations and then solving for the solutions in terms of this parameter.
Perturbation theory works by expanding the equations of a problem in terms of the perturbation parameter. This results in a series of equations, with each term representing a different level of approximation. The higher the order of the term, the more accurate the approximation will be.
Perturbation theory is commonly used in physics, engineering, and other scientific fields to solve problems that are too complicated or difficult to solve exactly. It is particularly useful for problems involving small changes or disturbances to a known system.
Perturbation theory is only applicable to problems where the perturbation parameter is small. If the perturbation is too large, the series of equations will not converge and the results will be inaccurate. Additionally, perturbation theory assumes that the system is linear, which may not always be the case.
Perturbation theory can involve complex mathematical notation, which can be confusing for those not familiar with it. It is important to understand the notation in order to properly apply perturbation theory and interpret the results. Therefore, it is common for those learning perturbation theory to have questions about the notation used.