Modified Friedmann equations from fractional entropy

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Çoker Z., Ökcü Ö., Aydıner E.

EPL, cilt.143, sa.5, 2023 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 143 Sayı: 5
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1209/0295-5075/acf158
  • Dergi Adı: EPL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Linguistic Bibliography, Metadex, zbMATH, Civil Engineering Abstracts
  • İstanbul Üniversitesi Adresli: Evet

Özet

Based on the fractional black-hole entropy (Jalalzadeh S. et al., Eur. Phys. J. C, 81 (2021) 632), we derive the modified Friedmann equations from two different frameworks. First, we consider the modifications of Friedmann equations from the first law of thermodynamics at the apparent horizon. We show that the generalized second law (GSL) of thermodynamics always holds in a region bounded by the apparent horizon. Then, we obtain Friedmann equations from Verlinde's entropic gravity framework. We also compute the fractional corrections to the deceleration parameter q in the flat case k = 0 for both frameworks. Furthermore, we consider the time to reach the initial singularity for the two frameworks. The results indicate that the initial singularity is accessible for both frameworks. However, fractional effects may provide a constraint on the equation-of-state parameter in the entropic gravity scenario since the time is imaginary for .