Analysis of Pantheon+ supernova data suggests evidence of sign-changing pressure of the cosmological fluid

2025/08/09 by A. Kazım Çamlıbel, Çamlıbel, A. Kazım, M. Akif Feyizoğlu +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Gamma-ray bursts and supernovae #General Relativity and Quantum Cosmology (gr-qc)

paper · doi:10.48550/arxiv.2508.06861

openalex publication_date 2025/08/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

In this work, we revisit/reinterpret/extend the model-independent analysis method (which we now call spread - luminosity distance fitting, spread-LDF) from our previous work. We apply it to the updated supernova type Ia catalogue, Pantheon+ and recent GRB compilations. The procedure allows us, using only FLRW assumption, to construct good approximations for expansion history of the universe, re-confirming its acceleration to be a robust feature. When we also assume General Relativity ("GR"), we can demonstrate, without any matter/energy model in mind, the need for (possibly nonconstant) dark energy ("GDE"). We find hints for positive pressure of GDE at z>1 with implications on either the complexity of dark energy, or the validity of one of the cosmological principle, interpretation of SN Ia data, or GR.

Citations

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Related

• Supernovae evidence for foundational change to cosmological models
• Non-Gaussian Likelihoods for Type Ia Supernovae Cosmology: Implications for Dark Energy and H₀
• Cosmological foundations revisited with Pantheon+
• Model-Independent Determination of the Cosmic Growth Factor
• Varying-G Cosmology with Type Ia Supernovae