Ground-state energy of a high-density electron gas in a strong magnetic field

The high-density electron gas in a strong magnetic field B and at zero temp erature is investigated. The. quantum strong-field limit is considered in w hich only the lowest Landau level is occupied. It is shown that the perturb ation series of the ground-state energy can be represented in analogy to th e Gell-Mann Brueckner expression of the ground-state energy of the field-fr ee electron gas. The role of the expansion parameter is taken by r(B) = (2/ 3 pi(2)) (B/m(2)) (hr(S)/e)(3) instead of the field-free Gell-Mann Brueckne r parameter r(s).