AC.2. International Commission on General Relativity and Gravitation

Report to the 2002 General Assembly for 1999-2002
Berlin, Germany
October 7-12, 2002

Activities

The principal activities of AC.2 (whose alter ego is the International Society on General Relativity and Gravitation) are its triennial conference (the GRn series of International Conferences on General Relativity and Gravitation), sponsorship of its journal, 'General Relativity and Gravitation', published by Kluwer, sponsorship of the email and Web information distribution service accessible at http://www.maths.qmul.ac.uk/hyperspace/ and widely-used by researchers in the field, and participation in international coordination of science via IUPAP and other bodies. In recent years the most important of these last have been PANAGIC and GWIC, both under IUPAP auspices. AC.2 also runs its own Web site at http://www.maths.qmul.ac.uk/grgsoc/

AC.2 held its 2001 conference, GR16, in Durban on 16-21 July. The attendance was a little down on previous events, especially from North America. This seems to have been for two main reasons. Air fares proved higher than anticipated, and there were concerns about security. Sadly the latter proved to be more of a real problem than had been expected, the situation having worsened in the three years since the site had been chosen. A further factor was the long distance between the site and that of the immediately preceding experimental gravitation meeting, the Amaldi conference in Perth, Australia. By working with GWIC, AC.2 expects to avoid that problem in future.

The venue proved to have excellent facilities and scientifically the meeting was very successful. There was the usual broad range of plenary talks (from the construction of gravity wave detectors to the theory of braneworld scenarios), many of them by younger researchers. There was also the usual large number of contributed papers for the parallel sessions. In all, there were 18 plenary talks, 21 workshops, some of them with multiple sessions, and a well-attended popular lecture by Prof. Jayant Narlikar. The Xanthopoulos Prize was awarded to Juan Maldacena, author of the eponymous conjecture relating anti-de Sitter spaces and conformal field theories on their boundary. Over 100 participants without adequate funding (colleagues from developing countries and students) were supported financially by IUPAP, AC.2's own resources, and other sources. The Gravity Research Foundation sponsored three plenary speakers, as before chosen to broaden the scope of the meeting. Prof. James Hartle made a donation which was used to initiate the Hartle Awards, consisting of free Society membership for three years each for the best contributed paper presentations by students. It is expected that the conference proceedings will appear shortly. The AC.2 General Assembly decided that the July 2004 conference will be held in Dublin, Ireland.

AC.2's journal experienced some problems arising from the takeover of Plenum by Kluwer. The main ones were administration problems with subscriptions, late publication, and withdrawal of the use of authors' own LaTeX. Steps have subsequently been taken by Kluwer to remedy these problems and the situation seems to be improving. The size of the journal has risen substantially, almost doubling in seven years, which reflects the rise in submissions since the rejection rate remained comparable with other physics journals. In the 2000 table of impact factors, the journal came 96th out of 445 journals in the Astronomy, Mathematics, and relevant Physics categories, showing quite a high standing for a specialist journal. One successful special series of papers has been the 'Golden Oldies', reprints and/or translations of classic papers in the field which are only available in languages other than English and/or in rather inaccessible books or journals.

As well as the journal, the following matters were discussed or reported at the General Assembly of AC.2. Membership has increased slightly and its finances are stable. Dues will rise from 2002. Prof. R.M. Wald was elected as the new President.

AC.2 were pleased that their proposal of Prof. Virginia Trimble as a member of the selection committee for the Peter Gruber Cosmology prize was adopted by IUPAP: she has taken part in the selection for 2001 and 2002 and has been re-nominated for the next term of office.

One of the Society's concerns is to broaden its membership base and activities so that it better represents the people coming into the field from both experimental physics, where the advent of the ground-and space-based interferometric detectors and other satellite experiments (such as the possible tests of the equivalence principle) has led to much larger teams than was the case in the past, and from theoretical physics, where string theory and the string-motivated higher-dimensional models such as braneworlds, and to a lesser extent loop quantum gravity, and the 'astroparticle physics' and early universe studies which form such a major part of modern comsology, have also drawn in many researchers.

The areas of expansion just mentioned cover some of the most exciting and novel new work, but there is also growth in some classical areas, notably the modelling of gravitational wave sources, because of its great relevance to the data analysis of the gravity-wave detectors' output. The connections arising from this work have meant that AC.2 now has an interest in high-performance numerical computing and Grid facilities for data handling.

In addition to the scientific areas mentioned, the recent (BOOMERANG) results on the Cosmic Microwave Background, which spectacularly confirmed predictions from inflation theory of the 'Doppler peaks', provided challenges for gravity theory in understanding the physics of dark matter and dark energy and the coincidence of their densities. Forthcoming high-precision satellite measurements (by MAP and Planck) will provide additional stimulus in this area. Other observations of great interest to AC.2 include the evidence for existence of black hole event horizons from X-ray observations of iron lines in active galactic nuclei.

The use of the Los Alamos electronic archive is widespread among researchers in AC.2's area. AC.2 therefore supports IUPAP activities on related questions, and also was pleased to support the initiatives of the Working Group on Women in Physics.

M.A.H. MacCallum, Secretary