2006/10/26 by Herman J. Mosquera Cuesta, Cuesta, Herman J. Mosquera, Rodrigo Turcati +8
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.astro-ph/0610796
openalex publication_date 2006/10/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Hubble diagram (HD) of Gamma-Ray Bursts (GRBs) having properly estimated redshifts is compared with the predicted one for the Chaplygin gas (CG), a dark energy candidate. The CG cosmology and that of Friedmann and Λ-CDM models are studied and confronted to the GRBs observations. The model-to-sample χ2 statistical analysis indicates the CG model as the best fit. The present GRBs HD plot exhibits a marked trend: as one goes back in time, it gets much closer to the predict HD for a Friedmann universe. This clear trend conclusively demonstrates that a transition from decelerate to accelerate expansion did take place. However, contrarily to claims based on supernovae type Ia, the transition redshift lies somewhere between ∼ 2.5 < z ≃ 3.5 rather than at z ∼ 0.5-1. All of these striking features of the GRBs HD constitute the most robust demonstration that the Chaplygin gas can in fact be the universe's driving dark energy field.