| 释义 |
Jordan's LemmaJordan's lemma shows the value of the Integral
 | (1) |
along the Real Axis is 0 for ``nice'' functions which satisfy . This isestablished using a Contour Integral which satisfies
 | (2) |
To derive the lemma, write
and define the Contour Integral
 | (5) |
Then
Now, if , choose an such that , so
 | (7) |
But, for ,
 | (8) |
so
As long as , Jordan's lemma
 | (10) |
then follows.See also Contour Integration References
Arfken, G. Mathematical Methods for Physicists, 3rd ed. Orlando, FL: Academic Press, pp. 406-408, 1985. |