Nonlinear corrections in basic problems of electro- and magneto-statics in the vacuum

Understand

We find third-power nonlinear corrections to the Coulomb and other static electric fields, as well as to the electric and magnetic dipole fields, as we work within QED with no background field.

• The nonlinear response function we base our consideration on is the fourth-rank polarization tensor, calculated within the local (infrared) approximation of the effective action.
• Therefore, the results are applicable to weakly varying fields.
• It is established that the nonlinear correction to magnetic moment of some baryons just matches, in the order of magnitude, the existing gap between its experimental and theoretical values.