Ponente
Descripción
The ∆CDM model, our standard framework for cosmology, has been remarkably successful in describing a vast range of cosmic observations. However, its core assumptions are being challenged by a series of persistent anomalies in observational data. This presentation will provide a comprehensive review of the current status of these cosmological tensions. We will first discuss the recent resolution of the growth (𝑆_8) tension, where final data from weak lensing surveys and new cluster counts now show improved consistency with the value predicted by Planck. This significant development simplifies the theoretical landscape and brings the three surviving tensions into sharper focus: The 𝐻_0 (Hubble) Tension: The persistent ~5 discrepancy between early-universe measurements from the CMB (like Planck) and late-universe "distance ladder" measurements (like SHOES). The DESI BAO-CMB Tension: The new evidence from DESI DR2, which conflicts with the ∆CDM model. When combined with other datasets, the data shows a strong statistical preference for a Dynamical Dark Energy (DDE) that evolves and crosses the phantom divide. The Cosmic Dipole Tension: The presence of large-scale anisotropies in various observational probes, which appears to challenge the Cosmological Principle, the foundational assumption of isotropy. Finally, we will review the primary classes of theoretical models proposed to address these anomalies. These include early-time models (e.g., Early Dark Energy), late-time 𝐻(𝑧) deformations (e.g., ∆sCDM ), and ultra-late-time transitions (z~0.01). We will also discuss how modified gravity frameworks, such as scalar-tensor theories, are being explored as a physical basis for both the dynamical dark energy signal and ultra-late transitions.
