Physics of Dense Matter
Y.C. Leung
268 pp. World Scientific, Singapore
(Teaneck, N.J.), 1985.
ISBN 9971-978-10-5. S47.00
12854
Supernova 1987a is a timely reminder of the rich and fascinating physics of dense matter and its role in supernovae and neutron stars. Few problems have such fundamental appeal and involve such a rich blend of nuclear physics, particle physics, astrophysics and condensed matter physics.
One essential ingredient for understanding supernovae and neutron stars is the equation of state of equilibrated matter. Y.C. Leung has written a clear, pedagogical introduction to our present understanding of the equation of state of condensed matter from terrestrial densities to beyond the densities found within nuclei. Leung assumes no prior or specialized background and his thorough and detailed treatment is easily accessible to an advanced undergraduate student or beginning graduate student with a knowledge of quantum mechanics. Particularly valuable is his treatment of the regime up to nuclear density, for which the relevant approximations have been tested quantitatively in experiments on atomic nuclei. In no other place, to my knowledge, can a student find collected so conveniently all the relevant ingredients of many-body physics, atomic physics and nuclear physics: the Thomas-Fermi, Hartree-Fock and thermal Hartree-Fock approximations; a review of nuclear interactons; and the independent-pair and variational treatments of nuclear matter. From these ingredients, Leung provides a quantitative description of how matter progresses from the low-density state, consisting of isolated nuclei; through the region of subnuclear densities, in which the high Fermi enegy of electrons results in increasingly neutron-rich nuclei and eventually forces neutrons out of nuclei; and to the emergence of a uniform quantum liquid at nuclear density. The last section of the book treats the more controversial region above the density of nuclear matter, providing a brief survey of meson-nucleon field theory, pion condensation and quark matter. In contrast to earlier sections, the treatment of these topics is not self-contained, and serves only as an introduction. Numerical tables of the calculated equation of state are provided in an appendix, a thoughtful convenience for those who wish to use the equation of state in astrophysical calculations.
If the book has any fault, it is that treating so rich a topic in 268 pages necessarily leaves much unsaid. Conspicuously absent is discussion of superfluidity and the associated pinning of vortices to nuclei in the neutron drip regime, which are important for understanding pulsar glitches. There is no discussion of strange matter nor of the possibility that it is in fact the true ground state of matter. The few experimental facts that constrain the equation of stateÑsuch as the compression modulus obtained from giant monopole resonances, and the limits placed by the measured masses of neutron starsÑare not mentioned. These omissions are consistent with the fact that the most recent references cited are from 1982. Clearly, Leung has chosen to focus his book on older aspects of dense matter physics that are reasonably well understood. For readers who seek a clear, readable presentation of this physics, and are not put off by photoreproduction of a typewritten manuscript in the era of computer-driven laser printers, this book is an excellent reference.
John W. Negele
Center for Theoretical Physics, MIT