Evolution of clustering in cosmological models with time-varying dark energy

Understand

Observations favor cosmological models with a time-varying dark energy component.

• But how does dynamical dark energy (DDE) influence the growth of structure in an expanding Universe? We investigate this question using high-resolution $N$-body simulations based on a DDE cosmology constrained by first-year DESI data (DESIY1$+$DDE), characterized by a 4% lower Hubble constant ($H_0$) and 10% higher matter density ($\Omega_0$) than the Planck-2018 $\Lambda$CDM model.
• We examine the impact on the matter power spectrum, halo abundances, clustering, and Baryonic Acoustic Oscillations (BAO).
• We find that DESIY1$+$DDE exhibits a 10% excess in power at small scales and a 15% suppression at large scales, driven primarily by its higher $\Omega_0$.