Langevin equation — application to liquid state dynamics

  • K. N. Pathak
Conference paper
Part of the Lecture Notes in Physics book series (LNP, volume 184)


In these lectures I have introduced various relevant correlation functions which are essential in the study of atomic motion of liquids. The generalized Langevin equation has been discussed and procedure to make calculations from it is outlined. A mode coupling theory for the VAF has been discussed which quite successfully explains the experimental data, as well as known long time tail. Collective excitations are discussed within the framework of phenomenological theory. It is emphasized that the liquid Argon type system can be understood in terms of essentially one relaxation time, whereas for liquid metal type systems, two distinct relaxation times are essential. Recent microscopic calculations are also pointed out. In our opinion it would be of interest to relate the two relaxation times to microscopic processes and interatomic potential. In conclusion it can be fair to say that microscopic dynamics of liquid state is still an open problem.

I am grateful to Mr. G.K. Agarwal without whose help it would have been impossible to prepare this draft. He has done an excellent job of organising and editing the manuscript.


Collective Excitation Mode Coupling Theory Velocity Autocorrelation Function Generalize Langevin Equation Relaxation Kernel 
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Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • K. N. Pathak
    • 1
  1. 1.Department of PhysicsPanjab UniversityChandigarhIndia

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