27th Spanish Relativity Meeting (ERE-2003)

Juan A. Miralles (Alicante), José A. Font (Valencia), José A. Pons (Alicante) ja.miralles@ua.es, ja.miralles@ua.es, jose.pons@ua.es
The 27th Spanish Relativity Meeting (ERE-2003) was held at the University of Alicante (Spain) from September 11 to 13, 2003. The Spanish Relativity Meetings are annual conferences on General Relativity which started back in 1977, each year being organized by one of the different groups doing research on Relativity and Gravitation in Spain. In this occasion the meeting was jointly organized by groups from the University of Alicante and the University of Valencia. A brief history of these meetings can be found online at the conference web site http://www.sri.ua.es/congresos/ere2003/ereeng.htm

The scope of the conference has expanded over time as a follow up of research activity in Relativity and Gravitation in Spain. The program of the 27th edition included a series of six plenary lectures in the mornings, plus several shorter communications, both in the morning and in the afternoon, where participation of young scientists was, as usual, encouraged. The number of delegates attending the meeting was over sixty people, mostly from Spain but also from abroad. A total number of thirty-three contributed talks were presented, covering a broad range of topics including cosmology, numerical relativity, and formal aspects of mathematical relativity. The subjects of the plenary lectures covered topics of current interest in the field of Gravitational Radiation. The abstracts of these talks can be accessed online at the conference web site http://www.sri.ua.es/congresos/ere2003.

Ewald Müller (MPA, Germany) gave a review talk on core collapse supernovae as sources of gravitational radiation. In particular he showed pioneer results on the gravitational wave emission from simulations of highly aspherical models on which the asphericities are caused by convective mass flow both in the proto-neutron star and in the post-shock neutrino heated hot bubble region.

In his talk Nils Andersson discussed the various ways in which neutron stars may give rise to detectable gravitational waves. He described the modeling of these systems which requires an understanding of much of modern physics, ranging from general relativity to superfluidity and nuclear physics at extreme densities. The main aim of his talk was to outline how gravitational-wave data can be used as a probe of exotic physics in neutron stars.

Signal detection was discussed in the corresponding talks of Alberto Lobo (University of Barcelona), Alicia Sintes (University of the Balearic Islands and AEI), Pia Astone (University of Rome), and B. Sathyaprakash (Cardiff University). In particular Pia Astone discussed recent controversial results obtained with two gravitational wave resonant bar detectors, Explorer (located at CERN) and Nautilus (in Frascati, LNF). These detectors are allowing to investigate various classes of signals, such as bursts, continuous waves, stochastic background. They operated in the year 2001 with unprecedented sensitivities, being potentially able to detect the conversion of $10^{-4}$ solar masses in the Galaxy into gravitational waves.

Alicia Sintes presented a talk focused on the search of continuous gravitational waves from rotating neutron stars, which are among the most promising sources for ground based interferometer detectors. Although young rapidly rotating neutron stars are probably better initial candidates for gravitational wave detection than the known set of radio pulsars, the data analysis problem for these putative sources is more difficult because of their unknown location and frequency evolution. Since the expected gravitational wave amplitude from pulsars is very weak, it is necessary to integrate the data for long periods of time (months to year) with the signal-to-noise ratio increasing roughly as the square root of the observing time. Several data analysis techniques have been used, and others are under development, which are able to handle efficiently these long stretches of data. These techniques were thorough fully discussed in her talk.

The problem of searching for black hole binaries was discussed in the talk by B. Sathyaprakash. Post-Newtonian calculations and numerical relativity simulations have provided with waveform templates that can be effectively used to identify the inspiral and merger signals buried in noisy data. Sathyaprakash presented the state-of-the-art techniques of search algorithms tailored to dig out signals of known shape, which have been developed and implemented to increase the chance of detection. Applying these waveform templates and search algorithms on real data have taught us important lessons about how to deal with problems arising from handling non-stationary and non-Gaussian backgrounds.

Alberto Lobo gave a review talk on LISA, the first space borne gravitational wave detector, a joint ESA-NASA mission scheduled for launch in 2011. He presented the scientific objectives of LISA, as well as its present development status. Lobo also described the situation of the Spanish involvement in the mission.

Finally, part of the meeting was devoted to discussing the establishment of the Spanish Society of Relativity and Gravitation (SEGRE). The 28th edition of the Spanish Relativity Meeting will take place in Madrid from September 22 to 24, 2004.

Jorge Pullin 2004-03-12