**PH-307 Thermal Physics **

- First law of thermodynamics, equilibrium, functions of state, internal energy; reversible changes, enthalpy, heat capacities, reversible adiabatic changes.
- Entropy, second law of thermodynamics, Carnot cycle; determination of entropy in irreversible processes, the approach to equilibrium.
- Microstates and macrostates, counting microstates, ensembles and ensemble averaging, approach to equilibrium.
- Classical probability, Statistical probability, axioms of probability theory, probability distributions, discrete and continuous distributions, binomial and Gaussian distributions, central limit theorem, combinatorics.
- Microcanonical systems, definition of a quantum state, entropy and equilibrium in a microcanonical system, the second law in statistical form (S=klnW)
- Canonical ensemble, partition function, entropy in canonical system, Boltzmann distribution, thermodynamical averages, applications to single particle, factorization of partition function.
- Equipartition theorem, free energy and its minimization, Gibbs and Helmholtz free energy and applications.
- Maxwell distribution of molecular speeds, classical probability of a state, Maxwell-Boltzmann probability distribution, density of states in k-space, distribution of speeds in a classical gas.
- Black body radiation, Rayleigh-Jeans theory, Planck distribution, free energy of a photon gas, Stefan-Boltzmann formula, phonons.
- Systems with variable number of particles, chemical potential, grand canonical ensemble, relation to thermodynamic variables.
- Identical particles, fermions and bosons, partition function for identical particles, semi-classical approximations, identical particles localized on a lattice, thermodynamic properties of a Fermi gas, low and high temperature regions, Bose condensation, applications to neutron stars.

**Recommended texts:**

*Introductory Statistical Mechanics,*by R. Bowley and M. Sanchez. Publisher: Clarenden Press, Oxford,*.**Thermal and Statistical Physics,*by H. Gould and J.Tobochnik, Publisher: Princeton University Press. (2010)*Introductory Statistical Physics,*by K. Huang, publisher: CRC, 1st Edition (2001)*.**Thermal Physics,*by C. Kittel and H. Kroemer, second edition, W. H. Freeman (1980)