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oai:docta.ucm.es:20.500.14352/44752025-08-08T14:06:28Zcom_20.500.14352_14col_20.500.14352_15

Sudden singularities in generalized hybrid metric-Palatini cosmologies Rosa, Joao Luis Lobo, Francisco S. N. Rubiera García, Diego Modified Gravity Black-holes Wormholes Space Física-Modelos matemáticos Física matemática © 2021 Iop Publishing JLR was supported by the European Regional Development Fund and the programme Mobilitas Pluss (MOBJD647). FSNL acknowledges support from the FCT Scientific Employment Stimulus contract with reference CEECINST/00032/2018 and funding from FCT Projects No. UID/FIS/04434/2020, No. CERN/FIS-PAR/0037/2019 and No. PTDC/FISOUT/29048/2017. DRG is funded by the Atraccion de Talento Investigador programme of the Comunidad de Madrid (Spain) No. 2018-T1/TIC-10431, and acknowledges further support from the Ministerio de Ciencia, Innovacion y Universidades (Spain) project No. PID2019108485GB-I00/AEI/10.13039/501100011033, the Spanish project No. FIS2017-84440-C2-1-P (MINECO/FEDER, EU), the project PROMETEO/2020/079 (Generalitat Valenciana), and the Edital 006/2018 PRONEX (FAPESQ-PB/CNPQ, Brazil) Grant No. 0015/2019. In this work, we explore cosmological sudden singularities arising in the dynamically equivalent scalar-tensor representation of generalized hybrid metric-Palatini gravity. Using a FLRW background, we show that the structure of the field equations prevents sudden singularities from arising at time derivatives of the scale factor of orders lower than four, but that they are allowed to appear for time derivatives of higher orders. Imposing an ansatz for the scale factor, we provide an explicit solution where these sudden singularities appear in the fourth-order time derivative of the scale factor. A comparison of the Hubble and deceleration parameters arising from this model with the experimental measurements from the Planck Satellite allow us to impose constraints on the time span for which the occurrence of sudden singularities becomes likely in our universe, as measured from the Big Bang. European Commission Ministerio de Economía y Competitividad (España) Ministerio de Ciencia e Innovación (España) Comunidad de Madrid Generalitat Valenciana Fundação para a Ciência e a Tecnologia (Portugal) Depto. de Física Teórica Fac. de Ciencias Físicas TRUE pub 2023-06-16T14:16:30Z 2023-06-16T14:16:30Z 2021 journal article https://hdl.handle.net/20.500.14352/4475 1475-7516 10.1088/1475-7516/2021/07/009 eng Mobilitas Pluss (MOBJD647) FIS2017-84440-C2-1-P PID2019108485GB-I00/AEI/10.13039/501100011033 2018-T1/TIC-10431 PROMETEO/2020/079 (CEECINST/00032/2018; UID/FIS/04434/2020; CERN/FIS-PAR/0037/2019; PTDC/FISOUT/29048/2017) (006/2018;PRONEX 0015/2019) open access application/pdf IOP Publishing