2025/10/09 by Chaudhary, Himanshu, Sharma, Vipin Kumar, Capozziello, Salvatore +1 · 5 citations
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2510.08339
Observational data play a pivotal role in identifying cosmological models that are both theoretically consistent and empirically viable. In this work, we investigate whether the standard ΛCDM model exhibits significant departure with current late time datasets, including Cosmic Chronometers, Baryon Acoustic Oscillations from DESI DR2, and various Type Ia supernova compilations (Pantheon+, DES-SN5Y, Union3). We analyze several dynamical dark energy models, including ωCDM, oωCDM, ω0ωaCDM, Logarithmic, Exponential, JBP, BA, and GEDE. While CC + DESI DR2 data show mild deviations from ΛCDM (\lesssim 2σ), adding supernova samples (DES-SN5Y or Union3) increases deviations, with BA, JBP, and Logarithmic models reaching 3-3.5σ, and CC + DESI DR2 + DES-SN5Y producing the largest deviations. We find consistent evidence for ω0 > -1 and ωa < 0 in all dark energy models, indicating that the cosmological constant faces a potential crisis and that dynamical dark energy models could provide a possible solution, characterized by a Quintom-B type scenario. The ΛCDM model has long served as the cornerstone of modern cosmology, successfully shaping our understanding of the Universe from its earliest epochs to the present day. However, in light of DESI DR2 and other recent measurements, emerging cracks in this paradigm suggest that a complete understanding of the cosmos may require moving beyond the cosmological constant and exploring new physics governing the dark sector.