Alleviating H 0 and S 8 Tensions Simultaneously in K-essence Cosmology

• Published in: The Astrophysical journal Vol. 975; no. 2; pp. 275 - 282
• Main Authors: Hosseini Mansoori, Seyed Ali, Moshafi, Hossein
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 01.11.2024; IOP Publishing
• Subjects: Cosmic inflation; Cosmic microwave background radiation; Early universe; Observational cosmology; Quantum cosmology; Supernovae
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ad8350

Abstract The present work begins by examining the early-Universe inflationary epoch of a special K-essence model, which incorporates a linear coupling term between the scalar field potential and the canonical Lagrangian. For the power-law potential, we both numerically and analytically prove that the inflationary parameters such as the spectral index and tensor-to-scalar ratio are compatible with the recent BICEP/Keck observations. Continuing this work, our analysis based on comparing early-Universe observations with late-Universe measurements indicates that the tension on the Hubble parameter H 0 and the growth of structure parameter S 8 can be alleviated simultaneously. More precisely, compared to the standard ΛCDM model, our model can reduce H 0 tension to roughly 2.2 σ , and the S 8 discrepancy diminishes to 0.82 σ .