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Results tagged with Search options user 3998

For questions where the dynamical variables are fields, that is, functions of several variables (typically, one time coordinate and several space coordinates). Comprises both classical field theory and quantum field theory. Use this tag when the question applies to both classical and quantum phenomena. Otherwise, use the specific tag instead.

2
votes
You started off stating that the undeformed solution ($\lambda=1$) must be a stationary point. So, if you differentiate the energy of this one-parameter family wrt $\lambda$ you should get zero. So ev …
answered May 1 '13 by Siva
2
votes
First, think of a source to be like a radio antenna (it is, after all, a source for electromagnetic fields). An antenna that can emit well can also absorb well. So $J(x)$ can model both a source and a …
answered Mar 24 '17 by Siva
5
votes
It's not quite correct to take $\Lambda \rightarrow \infty$, even at the end of the calculation. That comes from ancient mistaken notions that the field theory under consideration needs to describe ph …
answered Jun 25 '15 by Siva
21
votes
1answer
While deriving Noether's theorem or the generator(and hence conserved current) for a continuous symmetry, we work modulo the assumption that the field equations hold. Considering the case of gauge sym …
asked Oct 20 '11 by Siva