Crack in the cosmological paradigm

Abstract

A time-dependent dark energy component of the Universe may be able to explain tensions between local and primordial measurements of cosmological parameters, shaking current confidence in the concept of a cosmological constant.

Figures (1)

• Figure 1: Time evolution of the dark energy equation of state. The cosmological ‘constant’ (illustrated by the straight yellow line) is introduced to explain the accelerated expansion of the Universe (shown as the expanding pink cone) due to the presence of dark energy. Zhao et al. Zhao:2017cud instead suggest that the contribution of dark energy to this expansion is time-dependent (grey curve). The uncertainty of this time- dependency is also shown (green shaded area). Image credit: Gong-Bo Zhao, NAOC.