Friday, January 18, 2013

Four Potentials and EM Gauge Transformations

The cool thing I saw in EM yesterday.  So, we all know that you have freedom to choose the vector and scalar potential within a set of rules.  What I hadn't seen before, was the rules written down in a concise form next to each other:


If you look at the two right hand terms and then think of the two potentials making a four potential ala special relativity, 


you arrive at a much simpler way to memorize the rule for selecting gauges.  You can change either potential by the gradient of a scalar field as long as you compensate the other potential by adjusting the other potential with the negative of the gradient of the scalar field in its 'dimension', (time vs. space/scalar vs. vector).

Is there a more fundamental point we should get from this as well?


Picture of the Day:
From 1/18/13


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