  Several lines of evidence suggest that some of the dark matter may be
non-baryonic: the non-detection of various plausible baryonic candidates for
dark matter inferred, e.g., from galaxy rotation curves and from cluster of
galaxy velocity dispersions, the need for non-baryonic dark matter for
theoretical models of galaxy formation, and the large discrepancy between
dynamical measurements implying $\Omega_0 > 0.2$ and the baryon abundance
inferred from big bang nucleosynthesis, $\Omega_b h^2 = 0.015$. There are a
number of well-motivated dark matter candidates: massive neutrinos,
supersymmetric dark matter and ``invisible'' axions. Many of these dark matter
candidates are potentially detectable by the current generation of dark matter
experiments.
