Nature of dark matter

Determine the fundamental nature, composition, and interaction properties of dark matter that account for astrophysical and cosmological observations incompatible with general relativity and known standard-model matter.

Background

Despite the success of GR and quantum theory, multiple astrophysical observations—such as galactic rotation curves and gravitational lensing—cannot be explained by visible matter alone, motivating the postulation of dark matter.

The author explicitly lists dark matter as one of the two biggest open observational problems, noting its typical treatment outside quantum gravity but acknowledging its potential relevance to guiding or confirming QG approaches.