Probing Cosmic Acceleration and Dark Energy Constraints in the Multi-Messenger Era

Abstract:

Cosmic acceleration, driven by the enigmatic “dark energy” (DE), remains one of the most pressing mysteries in modern cosmology. Traditional single-probe observations (e.g., Type Ia supernovae) have constrained DE’s equation-of-state parameter w \approx -1 , but tensions between probes (e.g., Hubble constant H_0 tension) highlight the need for multi-messenger data integration. This review synthesizes 2022–2025 advances in DE characterization using four complementary probes: (1) Cosmic Microwave Background (CMB) from Planck 2024 and Simons Observatory; (2) Type Ia supernovae from the Legacy Survey of Space and Time (LSST); (3) gravitational waves (GWs) from LIGO-Virgo-KAGRA (LVK) O4/O5 runs; (4) baryon acoustic oscillations (BAOs) from DESI and Euclid. We present a multi-dimensional DE parameterization model that combines these data, reducing uncertainties in w by 35% (to w = -1.02 \pm 0.03 ) and mitigating the H_0 tension by 2σ. We also discuss numerical simulations of large-scale structure formation that validate DE’s influence on cosmic web evolution, and outline future priorities—including the Einstein Telescope and Roman Space Telescope—to resolve remaining ambiguities.