  We present a study of the skewness of nuclear matter, which is proportional
to the third derivative of the energy per nucleon with respect to the baryon
density at the saturation point, in the framework of the Landau-Migdal theory.
We derive an exact relation between the skewness, the nucleon effective mass,
and two-particle and three-particle interaction parameters. We also present
qualitative estimates, which indicate that three-particle correlations play an
important role for the skewness.
