Light scattering in liquids with isotropic molecules

Light scattering in liquids with isotropic molecules 

Density fluctuations in liquids are zu companied by fluctuations in the polarizability a (the dielectric constant t, the refractive index /r) in the sp2ice element v. Due to these fluctuations, space elements of v seem to be quasiparticles with the dielectric constant t (the polarizability a and the refractive index /i ), which differ from the average macroscopic values Ae = d — c, Aa = a — a, Ap = fi — H- These quasiparticles are chaotically distributed in a matrix with the dielectric constant f. = c(= p ) and their numerical concentration is = jv. On the basis of Equation 2.1-33 (Kerker, 1969), we can write 

If the state equation of the liquid is known (Equation 1.2-33), then only two quantities remain as independent thermodynamic parameters. It follows that Ac can be expressed through fluctuations in two quantities, namely, V (or p) and T or P and T (the former pair is used more often)  

Detailed analysis (Fabelinski, 1965 Kerker, 1969 Vuks, 1977) shows the. second summand to be negligible in comparison with the first one, and 

These three expressions are referred to as Einstein s equations (Einstein, 1910 Fabelinski, 1965 Kerker, 1969 Vuks, 1977). Their comparison with experiment has turned out to be difficult owing to the complexity of representation of [ff de/dg)]T as experimental quantities. This question still raises debate (Shakhparonov, 1963, 1970 Fabelinski, 1965 Kerker, 1969 Vuks, 1970, 1977 Ioffe, 1983). 

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