Preface

This Special issue is dedicated to Jacques Friedel on the occasion of his 90^th birthday. The name Jacques Friedel does not need any introduction. He is a giant in many different areas of physics, and his seminal papers on superconductivity, magnetism, properties of metals, metallurgy and spectroscopy have become textbook material.

This Festschrift contains many articles written by Jacques’s friends and colleagues whose life was greatly affected by working closely with him in collaborations and scientific discussions. Several articles are written by scientists who have never met Jacques Friedel, but all of the authors have greatly benefited from his scientific contributions.

The issue is divided into sections corresponding to specific fields that have been greatly impacted by Friedel’s contributions, arranged sequentially according to the broadening of his scientific interests with time. It should be noted, though, that in actuality for Jacques Friedel all fields are interconnected and boundaries do not exist. The Festschrift reveals as much: many papers overlap different fields, so their sorting is quite vague.

Not only did all the authors enthusiastically respond to the invitation to contribute to the Festschrift, but they actively participated in its creation. They gave a lot of good advice, wrote letters, etc. We are especially grateful to Y. Brechet, D. Jerome, W. Harrison, G. Bergmann, J. Bok.

It was a great pleasure to prepare this Festschrift because, of all the wonderful papers written especially for this event. All of the authors have great respect and warmth towards Jacques Friedel. He is, indeed, a special person for all of us.

Our congratulations to Jacques, Jean, Paul and to his whole family! All of us, as well as all participants of the Festschrift are happy to know that Jacques Friedel is still in great shape and full of new ideas. We all look forward to celebrate his Centennial.

Editors

Editorial Board