gremezd
Apr11-09, 05:12 PM
How do we get this identity:
\frac{1}{x+i\epsilon}=P \frac{1}{x} - i\pi\delta (x),
where P denotes principle value..? And how do we define this principle value of \frac{1}{x}?
Or is it maybe just a simple definition?
\frac{1}{x+i\epsilon}=P \frac{1}{x} - i\pi\delta (x),
where P denotes principle value..? And how do we define this principle value of \frac{1}{x}?
Or is it maybe just a simple definition?