Transformation of the contour by strong collisions

P = arccos(/ J /JJ1), which does not influence the scattered light frequency. The result is 

The validity condition of sudden modulation theory is determined by the requirement of a quick change in J2 in comparison with its conservation time  

Owing to this fact, they may be sewed together in order to describe quantitatively the Q-branch transformation with density from a gas to the liquid state [133-5]. 

Fourier transformation of this equation yields the isotropic scattering spectrum [133] 

The intensity at the periphery of the line ( A a 1/tj) decreases as (Oq/htjO in accordance with the general rule (2.62) [20, 104]. However, the most valuable advantage of general formula (3.34) is its ability to describe continuously the spectral transformation from a static contour to that narrowed by motion (Fig. 3.1). In the process of the spectrum s transformation its maximum is gradually shifted, the asymmetry disappears and it takes the form established by perturbation theory. 

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