Very interesting result. Eq. (7) means del squared (del squared A sub X) i.e. that the second derivatives inside the first bracket on the right hand act on the second bracket, generating fourth order derivatives of various kinds. Del is a vector operator, so del squared = del dot del, and del fourth = (del dot del)(del dot del) = (del squared) squared. Note that Eq. (17) of Note 395(70 means that there should be a factor (1/9) multiplying the second term on teh RHS of Eq. (5) of Note 395(6), and a facor 1 / 81 multiplying the second term, so it is a rapidly converging series.
Date: Sat, Dec 30, 2017 at 9:38 PM
Subject: note 395(6)
To: Myron Evans <myronevans123>
I calculated the fluctuation terms of the magnetic vector potential. There is no fluctuation in 2nd order. The fourth and sixth order do contribute.
How do I have to interpret eq. (7)? Is this a product of derivatives which leads to mixed derivatives of type
d^2/dX^2 d^2/dY^2
etc.? Then I have to modify my calculations.
Horst