This volume is the proceedings of the Seventh Taniguchi International Sympo- sium on the Theory of Condensed Matter. The symposium was held for five days from September 10 to 14, 1984 at Kashikojima, Mie, Japan. Dynamical proces- ses and ordering on solid surfaces are the subjects of the symposium. About twenty participants stayed together at Shima Kanko Hotel, the symposium site, during the period. The intense and productive discussion in the bright sea- s ide atmosphere of Kashi koj ima is bel i eved to have been impress i ve to all the participants. Dynamical processes on solid surfaces are the target of recent theoreti- cal efforts in surface physics. Even if some of them are still in their in- fant stage, important aspects begin to appear and vital concepts start to shape themselves. Some topics in the symposium were the energy transfer re- lated with internal degrees of freedom of molecules, attempts to go beyond the trajectory approximati on, charge transfer and energy transfer between particles and solid surfaces, and related fundamental problems like adiaba- tic potentials and electronic structures.In particular, really actively di scussed was the time-dependent Newns-Anderson model wi thout and wi th the intraatomic Coulomb interaction and sometimes with the interaction to the surface plasmons or phonons. Surface effects on the optical processes were discussed with great interest, such as the ABC-related problems of exciton polaritons and rare gas adsorbates on metal surfaces.

This volume is the proceedings of the Tsukuba Institute ''87 on Fermi Surface Effects, which was held August 27-29, 1987, at Tsukuba Science City in Japan. The topic of the Institute, Fermi surface effects, is one of the fascinating subjects of solid-state physics. It has been known since Sommerfeld''s work that the conduction electrons of metals constitute a degenerate Fermi system, and it has also been recognized that the occu­ pation number of the electron states has a discontinuity across the Fermi surface. Several basic properties of metal electrons stem from this fact. Furthermore, it gives rise to a singular response of the metal electrons to local and dynamical perturbations of low frequency. Such singular behav­ ior of the metal electrons is called a Fermi surface effect. In his opening address, printed as the Foreword, Professor R. Kubo described Fermi sur­ face effects as due to "wild" behavior of the metal electrons. The Institute co~sisted of five invited lectures, each of which was two hours long and dealt with theoretical aspects of a subject related to Fermi surface effects. Each lecturer is an expert in the field, and gave an in­ tensive treatment of his own subject. The experiment of inviting only very few lecturers and allotting them ample time for both presentation and discussion seems to have been successful. This Institute, which was sponsored by the Japan Industrial Technology Association, will probably be followed by other institutes, forming a series.

This volume is the proceedings of the Seventh Taniguchi International Sympo- sium on the Theory of Condensed Matter. The symposium was held for five days from September 10 to 14, 1984 at Kashikojima, Mie, Japan. Dynamical proces- ses and ordering on solid surfaces are the subjects of the symposium. About twenty participants stayed together at Shima Kanko Hotel, the symposium site, during the period. The intense and productive discussion in the bright sea- s ide atmosphere of Kashi koj ima is bel i eved to have been impress i ve to all the participants. Dynamical processes on solid surfaces are the target of recent theoreti- cal efforts in surface physics. Even if some of them are still in their in- fant stage, important aspects begin to appear and vital concepts start to shape themselves. Some topics in the symposium were the energy transfer re- lated with internal degrees of freedom of molecules, attempts to go beyond the trajectory approximati on, charge transfer and energy transfer between particles and solid surfaces, and related fundamental problems like adiaba- tic potentials and electronic structures.In particular, really actively di scussed was the time-dependent Newns-Anderson model wi thout and wi th the intraatomic Coulomb interaction and sometimes with the interaction to the surface plasmons or phonons. Surface effects on the optical processes were discussed with great interest, such as the ABC-related problems of exciton polaritons and rare gas adsorbates on metal surfaces.

This volume is the proceedings of the Tsukuba Institute ''87 on Fermi Surface Effects, which was held August 27-29, 1987, at Tsukuba Science City in Japan. The topic of the Institute, Fermi surface effects, is one of the fascinating subjects of solid-state physics. It has been known since Sommerfeld''s work that the conduction electrons of metals constitute a degenerate Fermi system, and it has also been recognized that the occu­ pation number of the electron states has a discontinuity across the Fermi surface. Several basic properties of metal electrons stem from this fact. Furthermore, it gives rise to a singular response of the metal electrons to local and dynamical perturbations of low frequency. Such singular behav­ ior of the metal electrons is called a Fermi surface effect. In his opening address, printed as the Foreword, Professor R. Kubo described Fermi sur­ face effects as due to "wild" behavior of the metal electrons. The Institute co~sisted of five invited lectures, each of which was two hours long and dealt with theoretical aspects of a subject related to Fermi surface effects. Each lecturer is an expert in the field, and gave an in­ tensive treatment of his own subject. The experiment of inviting only very few lecturers and allotting them ample time for both presentation and discussion seems to have been successful. This Institute, which was sponsored by the Japan Industrial Technology Association, will probably be followed by other institutes, forming a series.