Measurements of H0 and reconstruction of the dark energy properties from a model-independent joint analysis

Author(s)

Bonilla, Alexander ^[1] ; Kumar, Suresh ^{[2, 3]} ; Nunes, Rafael C. ^[4]

Affiliation

^[1] Univ Fed Juiz de Fora, Dept Fis, BR-36036330 Juiz De Fora, MG - Brazil

^[2] Natl Inst Technol, Dept Math, Kurukshetra 136119, Haryana - India

^[3] BITS Pilani, Dept Math, Pilani Campus, Pilani 333031, Rajasthan - India

^[4] Inst Nacl Pesquisas Espaciais, Div Astrofis, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN PHYSICAL JOURNAL C; v. 81, n. 2 FEB 2021.
• Web of Science Citations: 1

Abstract

Gaussian processes (GP) provide an elegant and model-independent method for extracting cosmological information from the observational data. In this work, we employ GP to perform a joint analysis by using the geometrical cosmological probes such as Supernova Type Ia (SN), Cosmic chronometers (CC), Baryon Acoustic Oscillations (BAO), and the H0LiCOW lenses sample to constrain the Hubble constant H0, and reconstruct some properties of dark energy (DE), viz., the equation of state parameter w, the sound speed of DE perturbations cs2</mml:msubsup>, and the ratio of DE density evolution X=rho de/rho de,0. From the joint analysis SN+CC+BAO+H0LiCOW, we find that H0 is constrained at 1.1% precision with H0=73.78 +/- 0.84<mml:mspace width={''}4pt{''}></mml:mspace>km<mml:mspace width={''}4pt{''}></mml:mspace>s-1<mml:mspace width={''}0.166667em{''}></mml:mspace>Mpc-1, which is in agreement with SH0ES and H0LiCOW estimates, but in similar to 6.2 sigma tension with the current CMB measurements of <mml:msub>H0. With regard to the DE parameters, we find cs2<0 at <similar to>2 sigma at high z, and the possibility of X to become negative for z>1.5. We compare our results with the ones obtained in the literature, and discuss the consequences of our main results on the DE theoretical framework. (AU)

• FAPESP's process: 18/18036-5 - Investigating physical aspects beyond the standard model linked to the themes of dark energy, modified gravity, neutrinos and gravitational waves
• Grantee: Rafael da Costa Nunes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral