New modified cosmology from a new generalized entropy

dc.contributor.authorLuciano, Giuseppe Gaetano
dc.contributor.authorSaridakis, E.N.
dc.date.accessioned2026-07-30T07:51:34Z
dc.date.available2026-07-30T07:51:34Z
dc.date.issued2026
dc.description.abstractWe develop new modified cosmological scenarios by applying the first law of thermodynamics at the Universe horizon, utilizing a new entropic functional that generalizes the standard Boltzmann-Gibbs-Shannon entropy. In particular, starting from the general theory of entropy in terms of the probability distribution over the accessible microstates, and by imposing violation of the separability requirement and thus considering a generalized microstate scaling, we result to a generalized entropy expression, which applied in systems with boundaries yields a generalized holographic-like area-law scaling with two exponents. Hence, incorporating it within the gravity-thermodynamics framework we result to a modified cosmological scenario with additional terms which eventually give rise to an effective dark energy sector. We extract analytical expressions for the dark energy density and equation-of-state parameters, and we show that the Universe experiences the usual thermal history, with the sequence of matter and dark-energy eras. Additionally, depending on the values of the entropic exponents, the dark energy can be quintessence-like, phantom-like or experience the phantom-divide crossing during its evolution, ultimately stabilizing at the cosmological constant value in the asymptotic far future, a behavior richer than other entropic modified cosmologies.
dc.identifier.doihttps://doi.org/10.1016/j.physletb.2026.140703
dc.identifier.issn0370-2693
dc.identifier.urihttps://hdl.handle.net/10459.1/471011
dc.language.isoeng
dc.publisherElsevier
dc.relation.isformatofReproducció del document publicat a https://doi.org/10.1016/j.physletb.2026.140703
dc.relation.ispartofPhysics Letters B, 2026, vol. 879, núm. 140703, p. 1-11
dc.rightscc-by (c) Luciano et al., 2026
dc.rightsAttribution 4.0 International*
dc.rights.accessRightsinfo:eu-repo/semantics/openAccess
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/*
dc.subjectBackground cosmology
dc.subjectNon-extensive entropy
dc.subjectGravity
dc.titleNew modified cosmology from a new generalized entropy
dc.typeinfo:eu-repo/semantics/article
dc.type.versioninfo:eu-repo/semantics/publishedVersion
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