We apply the recently developed critical minimum energy subspace scheme for
the investigation of the random-field Ising model. We point out that this
method is well suited for the study of this model. The density of states is
obtained via the Wang-Landau and broad histogram methods in a unified
implementation by employing the N-fold version of the Wang-Landau scheme. The
random-fields are obtained from a bimodal distribution (hi​=±2), and the
scaling of the specific heat maxima is studied on cubic lattices with sizes
ranging from L=4 to L=32. Observing the finite-size scaling behavior of the
maxima of the specific heats we examine the question of saturation of the
specific heat. The lack of self-averaging of this quantity is fully illustrated
and it is shown that this property may be related to the question mentioned
above.Comment: 8 pages, 7 figures, extended version with two new figures, version as
accepted for publication to Physical Review