Collective mode description for a clean Fermi gas with repulsion in arbitrary dimensions: interaction of spin excitations and its consequences

We discuss a recent bosonization method developed to study clean Fermi gases with repulsion in any dimensions. The method enables one to consider both density and spin excitations. It is demonstrated that due to a non- Abelian structure of the effective theory, the spin excitations interact with each other, which leads to new logarithmic in temperature corrections to physical quantities. Using a renormalization group scheme constructed for the effective low energy field theory these logarithms are summed up in all orders. Temperature dependent corrections to the specific heat and spin susceptibility are obtained for all dimensions d = 1, 2, 3.