 #1
 24
 1
Hello, I'm just starting Zee's QFT in a Nutshell, I'm a bit confused about what he means by "integate by parts under the d4x". Can someone explain what he means by this? I understand how to obtain the KleinGordon equation from the free particle Lagrangian density, but not sure why he invokes integration by parts.
Thanks!
Thanks!
Attachments

111.9 KB Views: 328