Two-dimentional electron gas near full polarisation.

We establish the consistency of the Fermi liquid description and find a relation between the Fermi liquid constants for a two-dimensional electron system near the point of full polarization due to a parallel magnetic field H. Our results enable us to predict connections between different thermodynamic properties of the system. In particular, we find that near the point of full polarization Hc, the thermodynamic compressibility of the system experiences a jump with a subleading (Hc-H)1/2 dependence on the magnetic field. Also, the magnetization has a cusp with dependence of the type (H-Hc)+(Hc-H)3/2 at H<Hc.