Citation

BibTex format

@article{Borissova:2026:07/045,
author = {Borissova, J and Magueijo, J},
doi = {07/045},
journal = {Journal of Cosmology and Astroparticle Physics},
pages = {045--045},
title = {Modified Friedmann equations and non-singular cosmologies in                    <i>d</i>                    = 4 non-polynomial quasi-topological gravities},
url = {http://dx.doi.org/10.1088/1475-7516/2026/07/045},
volume = {2026},
year = {2026}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - <jats:title>Abstract</jats:title>                  <jats:p>                    Quasi-topological theories of gravity are known to resolve black-hole singularities. We investigate whether the same mechanism can remove cosmological singularities. Focusing on non-polynomial curvature quasi-topological gravities in                    <jats:italic>d</jats:italic>                    = 4 dimensions, we find three generic scenarios with the correct infrared limit but without a Big-Bang singularity, for universes filled with pure radiation or other standard matter. The first scenario yields a universe emerging from a de Sitter phase, a case for which the curvature invariants remain finite but the matter density diverges, albeit only at infinite affine distance.   The second one corresponds to a bouncing universe, and requires a multi-valued Lagrangian.The third possibility is an asymptotically Minkowski origin, reminiscent of an eternally loitering universe. The matter energy density for this solution is non-singular even at infinite affine distance and does not enter a super-Planckian regime, but is instead approximately constant for the past eternity.                  </jats:p>
AU  - Borissova,J
AU  - Magueijo,J
DO  - 07/045
EP  - 045
PY  - 2026///
SP  - 045
TI  - Modified Friedmann equations and non-singular cosmologies in                    <i>d</i>                    = 4 non-polynomial quasi-topological gravities
T2  - Journal of Cosmology and Astroparticle Physics
UR  - http://dx.doi.org/10.1088/1475-7516/2026/07/045
UR  - https://doi.org/10.1088/1475-7516/2026/07/045
VL  - 2026
ER  -
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