On Wed, Sep 22, 2010 at 9:18 PM, smichr <[email protected]> wrote: >> http://theoretical-physics.net/dev/src/quantum/qed.html#magnetic-mome... >> > > Just a note: In the section after "Neither the ultraviolet nor the > infrared divergence ..." a theta in the integrand starts appearing. > I'm not sure what that is. Should it be delta? (Is delta the dirac > delta function?)
It's the Heaviside step function. See here for some details how it is connected to delta(x): http://theoretical-physics.net/dev/src/math/other.html (go the the end of the section, just above "Distributions"). I was thinking about this, that it might get confusing to the reader, maybe I could add there a reference to the definition, or something, as some people use H(x) for the step function. Ondrej -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
