Search for dark-matter particles

Abstract

Experiments performed over the last two years have been n fy successful in drastically reducing the number of viable elementary particles that could possibly constitute the dark matter that dominates the large-scale gravitational dynamics of astronomical systems. The candidates that survive are the light neutrinos, the axion, and a supersymmetric particle with carefully chosen parameters called the neutralino. Baryonic dark matter, which might contribute not insignificantly over small scales, is perhaps present in the form of brown dwarfs, and a search for these is under way. In this article i first review the astrophysical studies which bear on the density and the phase-space structure of the dark-matter particles; then discuss the implications of the various direct and indirect searches for these particles; and, finally. point out alternative suggestions for the candidates and directions for further searches.