Published online by Cambridge University Press: 24 October 2008
A new form of the variation principle is given using the sum T of the Lagrangian L and the Hamiltonian as an action function. This new form of the variational principle enables us to find a new special action function, which conserves the chief features of Born's theory while changing some of its former results. To a given charge correspond two static solutions with central symmetry, one giving a finite, the other an infinite energy. The potential of the one (light) particle is analogous to that in Born's theory while the potential of the other resembles a potential barrier. Also, by using the new action function, the symmetry between electric and magnetic fields ceases to exist.
† Born, , Proc. Roy. Soc. A, 143 (1934), 1410CrossRefGoogle Scholar; quoted here as I.
‡ Here and later we use the summation convention, i.e. where a suffix appears twice, we take the sum from 1 to 4.
§ Born, and Infeld, , Proc. Roy. Soc. A, 144 (1934), 144CrossRefGoogle Scholar; quoted as II.
∥ Schrödinger, , Proc. Roy. Soc. A, 150 (1935), 465.CrossRefGoogle Scholar
† are dual to fkl, Pkl. Although we consider here only the case of special relativity, we shall distinguish between covarian and contravariant tensors; the rule of raising and of lowering indices is: these operations on the index 4 do not change the value of the tensor component, that on one of the indices 1, 2, 3 changes only the sign.
‡ We put, here and later, for c (the velocity of light) and for b (the absolute field) the value 1, i. e. the time and the field components are to be measured in natural units.
† Our considerations correspond to the special case when L depends only on F and not on G.
† II, loc. cit. p. 436.
† We could also find (6·1) from putting (2·9) and (2·10) for L and .
‡ Schrödinger, loc. cit. Schrödinger formulated it for complex vectors, but it can easily be formulated for real tensors fkl, Pkl. It is the transformation
where a 2 + b 2 = 1.
† Mie, G., Ann. Physik, 40 (1913), 1.CrossRefGoogle Scholar
‡ II, loc. cit. p. 438.
† II, loc. cit. p. 446.