# What aspects of QFT do mathematicians find troublesome? [closed]

What aspects of "conventional" quantum field theory (i.e. what's used by most practicing physicists) are considered to be lacking mathematical rigor?

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Possible duplicates: physics.stackexchange.com/q/4068/2451 and links therein. –  Qmechanic Jan 15 '13 at 6:16
You might get better answers if you ask mathematicians... –  user1504 Jan 15 '13 at 13:19
The Wick rotation comes to mind ... –  Dilaton Jul 30 '13 at 19:06