2020/10/02 by John D. Barrow, Spyros Basilakos, Emmanuel N. Saridakis · 2 citations
Mathematics · Physics and Astronomy · #Astrophysics #Big Bang nucleosynthesis #Black Holes and Theoretical Physics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Entropy (arrow of time) #Galaxies: Formation, Evolution, Phenomena #Gravitation #Mathematical physics #Mathematics #Nucleosynthesis #Parameterized complexity #Physics #Stars #Statistical physics #Theoretical physics #Thermodynamics #Upper and lower bounds #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1016/j.physletb.2021.136134
published as Phys.Lett.B 815 (2021) 136134 · 6 pages, 1 figure
arxiv created 2020/10/02 · openalex publication_date 2021/02/11 · arxiv updated 2021/02/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use Big Bang Nucleosynthesis (BBN) data in order to impose constraints on the exponent of Barrow entropy. The latter is an extended entropy relation arising from the incorporation of quantum-gravitational effects on the black-hole structure, parameterized effectively by the new parameter Δ. When considered in a cosmological framework and under the light of the gravity-thermodynamics conjecture, Barrow entropy leads to modified cosmological scenarios whose Friedmann equations contain extra terms. We perform a detailed analysis of the BBN era and we calculate the deviation of the freeze-out temperature comparing to the result of standard cosmology. We use the observationally determined bound on |δTfTf| in order to extract the upper bound on Δ. As we find, the Barrow exponent should be inside the bound Δ≲1.4×10−4 in order not to spoil the BBN epoch, which shows that the deformation from standard Bekenstein-Hawking expression should be small as expected.