First Constraints on a Pixelated Universe in Light of DESI

Pixelated dark energy is a string theory scenario with a quantum mechanically stable cosmological constant. The number of pixels that make up the universe slowly increases, manifesting as a time-dependent source of dark energy. DESI has recently reported evidence for dynamical dark energy that fits within this framework. In light of this, we perform the first cosmological analysis of the pixelated model. We find that the simplest model where the pixel growth rate is constant is unable to accommodate the data, providing a comparable fit to $\Lambda$CDM; but that models where the pixel growth rate is increasing and of order the Hubble constant today are compatible. Our analysis helps to clarify the features of UV constructions of dark energy necessary to accommodate the data.