Common Integrals in Quantum Field Theory - Integrals That Can Be Approximated By The Method of Stationary Phase

Integrals That Can Be Approximated By The Method of Stationary Phase

A common integral is a path integral of the form

where is the classical action and the integral is over all possible paths that a particle may take. In the limit of small the integral can be evaluated in the stationary phase approximation. In this approximation the integral is over the path in which the action is a minimum. Therefore, this approximation recovers the classical limit of mechanics.

Read more about this topic:  Common Integrals In Quantum Field Theory

Famous quotes containing the words method, stationary and/or phase:

    Methinks the human method of expression by sound of tongue is very elementary, & ought to be substituted for some ingenious invention which should be able to give vent to at least six coherent sentences at once.
    Virginia Woolf (1882–1941)

    It is the dissenter, the theorist, the aspirant, who is quitting this ancient domain to embark on seas of adventure, who engages our interest. Omitting then for the present all notice of the stationary class, we shall find that the movement party divides itself into two classes, the actors, and the students.
    Ralph Waldo Emerson (1803–1882)

    I had let preadolescence creep up on me without paying much attention—and I seriously underestimated this insidious phase of child development. You hear about it, but you’re not a true believer until it jumps out at you in the shape of your own, until recently quite companionable child.
    Susan Ferraro (20th century)