The authors review results due to the authors and to their colleagues in Moscow concerning the general theory of Hamiltonian systems of hydrodynamic type and the hydrodynamics of weakly deformed soliton lattices that were obtained in 1982-1988.
A short introduction - without details - to soliton lattices and the Whitham equation is given.
Chapter I. Hamiltonian theory of systems of hydrodynamic type
§1. General properties of Poisson brackets
§2. Hamiltonian formalism of systems of hydrodynamic type and Riemannian geometry
§3. Generalizations: differential-geometric Poisson brackets of higher orders, differential-geometric Poisson brackets on a lattice, and the Yang-Baxter equation
§4. Riemann invariants and the Hamiltonian formalism of diagonal systems of hydrodynamic type. Novikov’s conjecture. Tsarev’s theorem. The generalized hodograph method
Chapter II. Equations of hydrodynamics of soliton lattices
§5. The Bogolyubov-Whitham averaging method for field-theoretic systems and soliton lattices. The results of Whitham and Hayes for Lagrangian systems
§6. The Whitham equations of hydrodynamics of weakly deformed soliton lattices for Hamiltonian field-theoretic systems. The principle of conservation of the Hamiltonian structure under averaging
§7. Modulations of soliton lattices of completely integrable evolutionary systems. Krichever’s method. The analytic solution of the Gurevich-Pitaevskij problem on the dispersive analogue of a shock wave.
§8. Evolution of the oscillatory zone in the KdV theory. Multi-valued functions in the hydrodynamics of soliton lattices. Numerical studies
§9. Influence of small viscosity on the evolution of the oscillatory zone.