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From: brooks@lll-crg.ARPA (Eugene D. Brooks III)
Newsgroups: net.physics
Subject: Re: Quantum Field Theory
Message-ID: <760@lll-crg.ARPA>
Date: Sun, 4-Aug-85 17:59:50 EDT
Article-I.D.: lll-crg.760
Posted: Sun Aug  4 17:59:50 1985
Date-Received: Wed, 7-Aug-85 01:40:32 EDT
References: <453@sri-arpa.ARPA>
Organization: Lawrence Livermore Labs, CRG group
Lines: 17

> 	In ordinary QM a solution of Schodingers equation is a function
> of the form psi(c, t) where c is a variable ranging over configurations
> of the system.  Is the same true in QFT?  In QFT each configuration c
> is a distribution of the field in THREE-space?  Why does time have such
> a distinguished status?  Why shouldn't solutions of (whatever) physical
> equations be functions of the form psi(c') where c' ranges over
> configurations of the field in FOUR-space?  I'll have to think about
> this further.
Time does not have distinguished status, the t=0 surface just happens to be the
standard space like surface that is used to establish the initial conditions
of the field operators.  You can pick any space like surface you like to set
up the initial field operators and commutation relations.
If you pick the t=0 surface the equations of motion only involves the H
operator.  If you pick some other surface then the equations of motion
involves the full (H, Px, Py, Pz) operator and the t variable in the equations
of motion are replaced by a variable s, the distance along a normal to the
surface.