Rudolf Peierls

1. Crystal lattices. General theory 2. . Crystal lattices. Applications 3. Interaction of light with non-conducting crystals 4. Electrons in a perfect lattice 5. Cohesive forces in metals 6. Transport phenomena 7. Magnetic properties of metals 8. Ferromagnetism 9. Interaction of light with electrons in solids 10. Semi-conductors and luminescence 11. Superconductivity

Collective motions of a many-body system, such as translation, iotation and oscillation, may be incorporated approximately in a shell-model description by regarding the shell-model wave function as a trial function for a variational approach, and exploiting the fact that the expectation value of the energy is then independent of the location and orientation, and approximately independent of the size and shape of the potential well. If these degeneracies are removed in the usual way, one is led naturally to wave functions containing both shell-model and collective aspects and to approximate values for the translational, rotational and vibrational energies.

A quantitative discussion of the white line at the ${L}_{3}$ edge of platinum and its absence at the ${L}_{2}$ edge in x-ray absorption is presented. The predominance of ${d}_{\frac{5}{2}}$ character in the hole in the atomic $5d$ shell of Pt is shown to persist in the unoccupied portion of the $d$ band of the metal. The total weight in the ${L}_{3}$-edge white line is calculated and found consistent with the experimental value. A brief presentation of some experimental results is given including some suggestion of the range of validity of the sudden approximation in x-ray absorption.

Problems in theoretical physics often lead to paradoxical answers; yet closer reasoning and a more complete analysis invariably lead to the resolution of the paradox and to a deeper understanding of the physics involved. Drawing primarily from his own experience and that of his collaborators, Sir Rudolf Peierls selects examples of such from a wide range of physical theory, from quantum mechanical scattering theory to the theory of relativity, from irreversibility in statistical mechanics to the behavior of electrons in solids. By studying such surprises and learning what kind of possibilities to look for, he suggests, scientists may be able to avoid errors in future problems. In some cases the surprise is that the outcome of a calculation is contrary to what physical intuition seems to demand. In other instances an approximation that looks convincing turns out to be unjustified, or one that looks unreasonable turns out to be adequate. Professor Peierls does not suggest, however, that theoretical physics is a hazardous game in which one can never foresee the surprises a detailed calculation might reveal. Rather, he contends, all the surprises discussed have rational explanations, most of which are very simple, at least in principle. This book is based on the author's lectures at the University of Washington in the spring of 1977 and at the Institut de Physique Nucleaire, University de Paris-Sud, Orsay, during the winter of 1977-1978.

Like its predecessor, this book by the renowned physicist Sir Rudolf Peierls draws from many diverse fields of theoretical physics to present problems in which the answer differs from what our intuition had led us to expect. In some cases an apparently convincing approximation turns out to be misleading; in others a seemingly unmanageable problem turns out to have a simple answer. Peierls's intention, however, is not to treat theoretical physics as an unpredictable game in which such surprises happen at random. Instead he shows how in each case careful thought could have prepared us for the outcome. Peierls has chosen mainly problems from his own experience or that of his collaborators, often showing how classic problems can lend themselves to new insights. His book is aimed at both graduate students and their teachers. Praise for Surprises in Theoretical Physics: A beautiful piece of stimulating scholarship and a delight to read. Physicists of all kinds will learn a great deal from it.--R. J. Blin-Stoyle, Contemporary Physics