Abstract
It is shown that non linear effects in the two temperature soft photon comptonized disc are exhibited when one allows for a variable coupling (ln Λ) for protons and electrons. Besides providing a new way to obtain the conventional solution to the disc equations, this procedure shows that the solution of the two temperature soft photon comptonized disc is double valued. For spherical accretion there will be solutions only for accretion rates above a critical minimum value, independently of cooling mechanisms. For soft comptonized accretion discs two temperature solutions only exist for accretion rates below a maximum value. Below this value, the solutions have quite different behaviour in the upper and lower branches. Solutions will be gas pressure dominated in the upper branch and radiation pressure dominated in the lower branch. For Cygnus X-1 the authors found that turbulence is, at least, sonic.
