Assessing Cosmological Evidence for Nonminimal Coupling

The recent observational evidence of deviations from the Lambda cold dark matter model points toward the presence of evolving dark energy. The simplest possibility consists of a cosmological scalar field φ, dubbed "quintessence," driving the accelerated expansion. We assess the evidence for the existence of such a scalar field. We find that, if the accelerated expansion is driven by quintessence, the data favor a potential energy V(φ) that is concave, i.e., m^{2}=d^{2}V/dφ^{2}

• BC
  Beecroft-Cheltenham Civic Trust
• UO
  University of Oxford
• SA
  Science and Technology Facilities Council