A Puzzle on Fluctuations of Weights in Spin Glasses

In certain mean field models for spin glasses there occurs a one step replica symmetry breaking pattern. As an example of general 1/$N$-corrections in such systems, the fluctuations in the internal energy are calculated. For this quantity the outcome is known from the specific heat. It is shown that the correct result can be derived by assuming that the both the height and the location of the breakpoint fluctuate. This effect enlarges the commonly considered space of allowed fluctuations of the order parameter in loop calculations for short range spin glasses of this type. The phenomenon does not occur in spin glasses with infinite order replica symmetry breaking