Об определении релятивистской плотности заряда

Еще не читал, но возникла мысль: не связано ли это с тем, что когда-то писал Игорь Иванов о форме летящего протона (подборка ссылок тут)?

Comments and extensions of a recent suggestion for a relativistic charge density definition: https://arxiv.org/abs/2208.00826
Carl E. Carlson (William & Mary)
A recent suggested definition of a relativistically correct three dimensional charge density of an extended hadron is shown to be physically and intuitively connected to an earlier relativistically correct two dimensional charge density studied in the context of light-front physics. Looking at spin-1/2 hadrons, such a connection is shown to exist for both the polarized and unpolarized cases.
Comments: 4 pages, no figures