Cosmography and the redshift drift in Palatini theories

Florencia A. Teppa Pannia; Santiago E. Perez Bergliaffa; Nivaldo Manske

doi:10.1140/epjc/s10052-019-6764-x

EPJ

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2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2019) 79: 267
https://doi.org/10.1140/epjc/s10052-019-6764-x

Regular Article - Theoretical Physics

Cosmography and the redshift drift in Palatini $f({{\mathcal {R}}})$ theories

Florencia A. Teppa Pannia, Santiago E. Perez Bergliaffa^* and Nivaldo Manske

Departamento de Física Teórica, Instituto de Física, Universidade do Estado de Rio de Janeiro, Rio de Janeiro, CEP 20550-013, Brazil

^* e-mail: sepbergliaffa@gmail.com

Received: 13 November 2018
Accepted: 10 March 2019
Published online: 22 March 2019

Abstract

We present an application to cosmological models in $f({{\mathcal {R}}})$ theories within the Palatini formalism of a method that combines cosmography and the explicit form of the field equations in the calculation of the redshift drift. The method yields a sequence of constraint equations which lead to limits on the parameter space of a given $f({{\mathcal {R}}})$ -model. Two particular families of $f(\mathcal{R})$ -cosmologies capable of describing the current dynamics of the universe are explored here: (i) power law theories of the type $f({{\mathcal {R}}})={{\mathcal {R}}}-\beta /{{\mathcal {R}}}^n$ , and (ii) theories of the form $f({{\mathcal {R}}})={{\mathcal {R}}}+\alpha \ln {{{\mathcal {R}}}} -\beta$ . The constraints on $(n,\beta )$ and $(\alpha ,\beta )$ , respectively, limit the values to intervals that are narrower than the ones previously obtained. As a byproduct, we show that when applied to General Relativity, the method yields values of the kinematic parameters with much smaller errors that those obtained directly from observations.