Energy-momentum powered gravity and cosmic acceleration


Akarsu Ö., Katırcı N., Kumar S.

2017 Corfu Summer Institute "Schools and Workshops on Elementary Particle Physics and Gravity", CORFU 2017, Corfu, Greece, 2 - 28 September 2017, vol.318 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 318
  • City: Corfu
  • Country: Greece
  • Istanbul Technical University Affiliated: Yes

Abstract

© Copyright owned by the author(s) under the terms of the Creative Commons.We present a summary of the findings in energy-momentum powered gravity (EMPG) model studied in Ö. Akarsu, N. Katırcı, S. Kumar, Phys. Rev. D 97 (2018) 024011. In contrast to theories of non-linear gravity, which are based on generalizing the Einstein-Hilbert curvature contribution to the Lagrangian, we consider non-linear contributions of the usual energy-momentum tensor to the matter Lagrangian. We consider a particular form of them as f(TµνTµν) as f(TµνTµν) = α(TµνTµν)η, where α and η are real constants, dubbed as energy-momentum powered gravity (EMPG). We look for viable cosmologies arising from EMPG in the context of the late-time accelerated expansion of the Universe at the background level. We obtain late time acceleration in a dust-dominated Universe without invoking dark energy source like cosmological constant. With a recent compilation of 28 Hubble parameter measurements, we constrain the parameters of the EMPG model and we conclude that, although the underlying physics in the EMPG model is entirely different in the sense that the energy in the EMPG Universe is sourced by pressureless matter only, this model describes an evolution of the Universe similar to that in the ΛCDM model.