By Michele Maggiore, Oxford University Press. Hardback ISBN 9780198570745 £45 ($90).
This is a complete book for a field of physics that has just reached maturity. Gravitational wave (GW) physics recently arrived at a special stage of development. On the theory side, most of the generation mechanisms have been understood and some technical controversies have been settled. On the experimental side, several large interferometers are now operating around the world, with sensitivities that could allow the first detection of GWs, even if with a relatively low probability. The GW community is also starting vigorous upgrade programmes to bring the detection probability to certitude in less than a decade from now.
The need for a textbook that treats the production and detection of GWs systematically is clear. Michele Maggiore has succeeded in doing this in a way that is fruitful not only for the young physicist starting to work in the field, but also for the experienced scientist needing a reference book for everyday work.
In the first part, on theory, he uses two complementary approaches: geometrical and field-theoretical. The text fully develops and compares both, which is of great help for a deep understanding of the nature of GWs. The author also derives all equations completely, leaving just the really straightforward algebra for the reader. A basic knowledge of general relativity and field theory is the only prerequisite.
Maggiore explains thoroughly the generation of gravitational radiation by the most important astrophysical sources, including the emitted power and its frequency distribution. One full chapter is dedicated to the Hulse-Taylor binary pulsar, which constituted the first evidence for GW emission. The “tricky” subject of post-Newtonian sources is also clearly introduced and developed. Exercises that are completely worked out conclude most of these theory chapters, enhancing the pedagogical character of the book.
The second part is dedicated to experiments and starts by setting up a background of data-analysis techniques, including noise spectral density, matched filtering, probability and statistics, all of which are applied to pulse and periodic sources and to stochastic backgrounds. Maggiore treats resonant mass detectors first, because they were the first detectors chronologically to have the capability of detecting signals, even if only strong ones originating in the neighbourhood of our galaxy. The study of resonant bar detectors is instructive and deals with issues that are also very relevant to understanding interferometers. The text clearly explains fundamental physics issues, such as approaching the quantum limits and quantum non-demolition measurements.
The last chapter is devoted to a complete and detailed study of the large interferometers – the detectors of the current generation – which should soon make the first detection of GWs. It discusses many details of these complex devices, including their coupling to gravitational waves, and it makes a careful analysis of all of the noise sources.
Lastly, it is important to remark on a little word that appears on the cover: “Volume 1”. As the author explains in the preface, he is already working on the second volume. This will appear in a few years and will be dedicated to astrophysical and cosmological sources of GWs. The level of this first book allows us to expect an interesting description of all “we can learn about nature in astrophysics and cosmology, using these tools”.
