Green's Function
The Green's function for the d'Alembertian is defined by the equation
where is the Dirac delta function and and are two points in Minkowski space.
A special solution is given by the retarded Green's function which corresponds to signal propagation only forward in time
where is the Heaviside step function.
Read more about this topic: D'Alembert Operator
Famous quotes containing the words green and/or function:
“As the shade went up
And the ambulance came crashing through the dust
Of the new day, the moon and the sun and the stars,
And the iceberg slowly sank
In the volcano and the sea ran far away
Yellow over the hot sand, green as the green trees.”
—John Ashbery (b. 1927)
“Nobody seriously questions the principle that it is the function of mass culture to maintain public morale, and certainly nobody in the mass audience objects to having his morale maintained.”
—Robert Warshow (1917–1955)