Origin of dark energy

Ascertain the physical mechanism driving the observed accelerated expansion of the universe, including determining whether it is due to a cosmological constant or alternative dynamical phenomena, consistent with cosmological observations and theoretical constraints.

Background

Observations of type Ia supernovae and other cosmological probes indicate an accelerating universe that current models struggle to explain without introducing dark energy, often modelled via a cosmological constant.

The author identifies dark energy as one of the two major open observational problems; whether and how it should inform quantum gravity research remains debated, but resolving it is central to a complete cosmological theory.