Everpresent Lambda: Theory Meets Observations

One of the biggest mysteries in cosmology and fundamental physics is the nature of dark energy that is responsible for the current acceleration of cosmic expansion. While a cosmological constant provides the simplest model of dark energy, recent observational tensions amongst supernovae Ia, gravitational lensing time delays, and cosmic microwave background suggest the need for a more complex dynamical dark energy. One of the oldest proposals for a dynamical dark energy is “Everpresent Lambda” proposed by Sorkin, which is inspired by the causal set model of quantum gravity. It was recently shown that this model can potentially resolve the tensions in cosmological observations. The meeting aims to bring together a small number of experts in quantum gravity, causal sets, and cosmology, to carefully examine the model’s theoretical predictions and its observational tests, and pave the way for what might be an(other) exciting insight from cosmology into the fundamental nature of spacetime.