The main result of this note is as follows: Let M=∈SL(2,Z) be hyperbolic. Then the Atiyah’s invariant η(M)=-sign (trac (M))|m (M) Ψ_o (M), whore m(Mr) is th
The nonlinear interactions between the monochromatic wave have been considered by K. Matsunchi, who also proposed one class of the nonlinear Schrdinger equation