Statistical Mechanics

Module code: PA4606

Statistical mechanics is a broad subject with applications and implications in nearly every branch of physics and astrophysics. Its methods apply whenever a very large number of particles is being considered. This module builds on the concepts in classical thermodynamics and statistical mechanics covered in previous years and will bring clarity to the very foundations of statistical mechanics by considering simple 5-10 particle systems first in the classical mechanics limit. 

Bose-Einstein and Fermi-Dirac distributions are derived and contrasted to the classical Boltzmann distribution. Applications to be discussed include the thermal properties of matter, such as equation of state for hydrogen in molecular, atomic and ionised forms; specific heats of metals, black body radiation, Bose Einstein condensates, and properties of white dwarf and neutron stars.

Topics covered

  • Postulates of statistical mechanics
  • Properties of the fermi-dirac, bose-einstein, maxwell and boltzmann distributions
  • The statistical interpretation of thermodynamic quantities
  • Chemical potential, phases of matter, and reaction equilibria, such as hydrogen ionisation and h2 molecule dissociation


  • 30 hours of lectures
  • 2 hours of practical classes and workshops
  • 118 hours of guided independent study


  • Coursework (30%)
  • Exam, 2 hours (70%)