- #1

Matterwave

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How are they related? Can you derive one from another, or are they separate fields of study?

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- Thread starter Matterwave
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- #1

Matterwave

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How are they related? Can you derive one from another, or are they separate fields of study?

- #2

waht

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QED, and QCD and QFD are theories based on QFT.

- #3

diazona

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QED = "Quantum Electrodynamics" which is one example of a quantum field theory, where the fields are the electric and magnetic fields that arise from electrical charges and currents.

QCD = "Quantum Chromodynamics" which is another example of a quantum field theory, where the field comes from the "color charges" on quarks (and gluons I suppose).

- #4

malawi_glenn

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In order to stody QED and QCD, one has to study QFT first. And very very often, QED is assumed to be know in quite detail before you attempt to learn QCD. You can think of QFT as the analogy with the Schrödinger equation in QM. In Schrödinger equation, the potential is unknown, and you can use potentials to fit a known phenomenon. Examples: The Hydrogen Atom, use a Coulomb potential. For semiconductors, use a step potential. Etc. In Quantum Field theory, you do in a similar way, you include the fields, fermions and/or boson fields, and interaction terms, and then you start to calculate observables and see if they fit with experiments. Also, one would like to have underlying symmetries, like these local phase transformations.

- #5

Matterwave

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Ok, thanks. :)

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