In theoretical physics, specifically in discussing, electromagnetism, the potential of a nonlinear Coulomb field
- φ(g,x)
takes the dimensionless form
- φ(g,x) = gφ(x)
where g and a are scales for potentials and lengths.
The Lagrangian for the Nonlinear Coulomb field in dimentionless units is
Maxwell's nonlinear equation for the Coulomb potential is
or, equivalently,

- φ + = φ(0)
where for simplicity
: this mean that states with positive electric gauge are considered.
In the physical region
as
The Coulomb potential for the vacuum state is
- u + = u(0)
or, in dimensional form for a state with electric gauge e = ag, in CGS units ,
For the scalar velocity u0 there are several equations. Here two of them are considered.
In vacuum state
then u0 = u + + bx. Self energy any field must be finite so b = 0. Coulomn potential is
-
; u + (0)
Coherence condition for vacuum state is
-
-
Hence potentials vacuum are connect between themselves
- u + (φ + + 2γu + ) = 1
- 2u + (φ + + γu + ) = 3
From physical reason in this vacuum state u + = - 1 then φ + = - 2 and interaction constant
.
Lorentz gauge condition
, fields bevector
and linear Maxwells equations do not change at transformation
. In nonlinear model value potentials vacuum are determinate by coherence condition. There is analogy with relativistic machanics where energy free particle on infinity is fixid.
In coherent state equation for scalar velocity and solutions field equations are
;
;
where N is integer number and
because energy of free w-field must be finite.
Coherence condition for this state is
-
-
The state with N = 0 does not exist. States with N > 0 have electromagnetic structure because electric gauge density
change sign in intarnal area of field. Then there exist additional scale parameter, it is point corresponding u0 = 0
Scale lengths a and electric gauge e is unknown parameter of field and they are need in defining from other sources. Electromagnetic interaction determinate value of Lamb shift Then for electron
Linear Coulomb fields have infinite self-energy: this is the major difficulty of classical field theory. In nonlinear model all fields self energies are finite because dimensionless electrostatic force
speedily decrease when
.