Acknowledgements
Writing this book has been one of those ideas taken on a momentary lapse of reason and then
regretted for the uncountable hours spent honouring the initial commitment.
This book is the result of what we have learnt during the last 20 years through our own
research, the literature, the lectures given in different universities and schools, and, more
pleasantly, through discussions with colleagues and friends. All of them have contributed
to this effort more than they know, starting from those that have first introduced us to the
subject: John Miller, Marcello Anile, Fernando de Felice, Jos´e Mari´aIb´a˜nez, Jos´e Mari´a
Mart´ı, and Toni Font. We are also indebted to Ernazar Abdikamalov, Marek Abramowicz,
Bobomurat Ahmedov, Miguel Alcubierre, Miguel-Angel Aloy, Nils Andersson, Marcus An-
sorg, Luis Anton, Dinshaw Balsara, Enrico Barausse, Thomas Baumgarte, Nigel Bishop, Car-
les Bona, Alfio Bonanno, Silvano Bonazzola, Bernd Br¨ugmann, Marco Bruni, Joan Cen-
trella, Cecilia Chirenti, Riccardo Ciolfi, Frederic Daigne, Thibault Damour, Peter Diener,
Harry Dimmelmeier, Kyriaki Dionysopoulou, Orhan D¨onmez, Yoshiharu Eriguchi, Valeria
Ferrari, Bruno Giacomazzo, Eric Gourgolhon, Leonardo Gualtieri, Ian Hawke, Scott Hughes,
Hans-Thomas Janka, Thorsten Kellermann, Kostas Kokkotas, Pablo Laguna, Fred Lamb, Luis
Lehner, Lee Lindblom, Frank L¨offler, Richard Matzner, Juan Antonio Miralles, Phillip M¨osta,
Pedro Montero, Ewald M¨uller, Ingo M¨uller, Ilia Musco, Alessandro Nagar, David Neilsen,
Christian Ott, Carlos Palenzuela, Ornella Pantano, Tsvi Piran, Denis Pollney, Jos´e Pons,
Christian Reisswig, Constanze Roedig, Erik Schnetter, Bernard Schutz, Ed Seidel, Jennifer
Seiler, Stu Shapiro, Masaru Shibata, Nikolaos Stergioulas, B´ela Szil´agyi, Saul Teukolsky, Kip
Thorne, Manuel Tiglio, Aaryn Tonita, K¯oji Ury¯u and Shin’ichirou Yoshida.
We are also particularly grateful to Dana Alic, Luca Baiotti, Francesco Becattini, Roberto
De Pietri, Luca Del Zanna, Michael Dumbser, Filippo Galeazzi, Arturo Hidalgo, Pasi Huovi-
nen, Jos´e Luis Jaramillo, Wolfgang Kastaun, Jos´e Mari´aIb´a˜nez, Antonio Marquina, Jos´e
Mari´a Mart´ı, John Miller, Francesco Pannarale, David Radice, Dirk Rischke, Armen Se-
drakian, Christian Schell, Daniel Siegel, Kentaro Takami and Eleuterio Toro, for their careful
reading of the book and the numerous suggestions that have improved it. LR also thanks the
Institut des Hautes´Etudes Scientifiques (IHES) in Bur-sur-Yvette (France) and the Departa-
mento de Astronomia y Astrof´ısica (DAA) in Valencia (Spain) for the kind hospitality during
the visits when parts of this book were being written.
Last but not least we thank Oxford University Press and in particular S¨onke Adlung for
his continuous support and advice during the writing of this book.