F. Benbelgacem et al., A DENSITY RESULT FOR MAXWELLS EQUATIONS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 324(6), 1997, pp. 731-736
We prove the density of regular fields in the space of square-integrab
le fields with square-integrable curls and square-integrable tangentia
l traces on the boundary. this space is involved in one of the variati
onal formulations of the electromagnetism equations.