  We present results of Monte Carlo simulations, using parallel tempering, on
the three- and four-dimensional Edwards-Anderson Ising spin glass with Gaussian
couplings at low temperatures with free boundary conditions. Our results
suggest that large-scale low-energy excitations may be space filling. The data
implies that the energy of these excitations increases with increasing system
size for small systems, but we see evidence in three dimensions, where we have
a greater range of sizes, for a crossover to a regime where the energy is
independent of system size, in accordance with replica symmetry breaking.
