Analytic Continutation of Quantum Statistical Mechanics

[unchained1978]

In A. Zee's book "QFT in a Nutshell" he glosses over the idea that the path integral approach and the partition function are related loosely by the correspondence principle, and alludes to some deep fundamental insight behind QFT. But then he moves on. Anyone know where I could read up more on this?

 

[Bill_K]

Zee does a lot of glossing over, that's for sure, but maybe not in this case. He just points out the formal analogy and honestly admits he doesn't know a good reason for it. The ideas been around for quite a long time. Take a look at the Wikipedia page "Thermal quantum field theory", where they give some references.