This volume contains the proceedings of the Eighth Taniguchi Interna tional Symposium on the Theory of Condensed Matter, which was held at Shima Kanko Hotel in Shima, Japan, 10-13 April 1985. The topic of the Symposium was Valence Fluctuation and Heavy Fermion Systems, one of the most fundamental problems in present-day condensed matter physics. The dilute Kondo problem, which is one of the most typical and unique many-body problems in condensed matter physics, developed recently into the dense Kondo and the coherent Kondo lattice problems in the 4f elec tron systems. It is accepted now that a large degeneracy in f-electron systems makes this latter situation possible by enhancing the single-site Kondo state relative to the inter-site magnetic interactions. Now, anoma lous behavior in f-electron systems show rich variety and are called valence fluctuation phenomena as a whole. They have, however, a common fea ture. In the lowest temperature region, they show either heavy Fermion like character or a narrow gap formation at the Fermi energy. Discovery of superconductivity in the heavy Fermion systems is attracting more in terest. Anyway, the valence fluctuating states are thought to be of fun damental importance to bridge the gap between the localized magnetic states and the delocalized nownagnetic states.

Inhalt
I Introductory Survey on Theories and Experiments.- The c-f Mixing Interaction and Valence Fluctuation: Fundamental Considerations.- Heavy-Fermion Superconductivity: Experimental Status Report.- II Exact Solution for Single Impurity.- Exact Solution of the Anderson Model and Its Thermodynamics I.- Exact Solution of the Anderson Model and Its Thermodynamics II Including Crystalline Field and Spin-Orbit Coupling.- Bethe-Ansatz Solution of the Degenerate Anderson Model: Application to Ce and Yb Impurity Systems.- III Dynamical Properties of Single Impurity.- Kondo Effects versus Crystal Field.- The Frequency-Dependent Susceptibility in the Anderson Model.- IV Spectroscopy Properties.- Ground-State and Spectroscopic Properties of the Finite U Anderson Model.- PES and BIS Spectra in Ce-Compounds.- V Theories for Periodic Systems and Heavy Fermions.- Models for Intermediate Valence Systems and Kondo Lattices Applications to Cerium and Ytterbium Compounds.- Self-Consistent Perturbation Theory for Valence-Fluctuating Lattice Systems.- Modelling Mixed Valence Systems Using the Generalized Anderson Model.- Ground State of the Periodic Anderson Hamiltonian.- Quasiparticles in Heavy Fermi Liquids and Their Interactions With Phonons.- Z?1 Expansion in Dense Kondo Systems.- Heavy Electron Fermi Liquids Similarities and Differences to 3He.- VI Superconductivity in Heavy Fermion Systems.- Effect of an External Magnetic Field on the Coherent Kondo State Upper Critical Field in UBe13.- Superconductivity in Kondo Lattices.- Some Aspects of Heavy Fermion Superconductivity.- Heavy Electron Superconductors Some Consequences of the p-Wave Pairing.- Phenemenological and Some Microscopic Aspects of Heavy Fermi-Liquids and Their Superconductivity.- Index of Contributors.