Pablo Andrés Lizardo Romo defended his PhD thesis on 18 October 2024. Congrats!
The defense took place at the Unidad Académica de Física in Zacatecas, Zacatecas, Mexico
Pablo Andrés Lizardo Romo defended his PhD thesis on 18 October 2024. Congrats!
The defense took place at the Unidad Académica de Física in Zacatecas, Zacatecas, Mexico
Title: GRAVITATIONAL WAVES IN MODIFIED GRAVITY.
Abstract: In this thesis, an extensive review of the characteristics of the friction term in propagation of gravitational waves is carried out, with a primary focus on the novel approaches they offer for modern tests of theories of modified gravity. One of these approaches is the gravitational wave luminosity distance (dGW), which is directly obtained from the observation of gravitational wave events and can be compared with the electromagnetic luminosity distance (dL) to identify differences in the propagation of electromagnetic and gravitational waves. Along these lines, the study of dGW through parametrizations has recently been proposed. This methodology will be explored in this work by directly comparing the parametrizations with the predictions of some recent modified gravity models. Going forward, a new parametrization is proposed to unify the behaviors of the previous ones. In the second part of this thesis we shift our interest towards the background on which gravitational waves propagate. First we analyze if a parametrization of the background is viable for a wide range of modified gravity models. For the observational part of this analysis we use strong lensing system data. Then, we test if the parametrized background can be used to simplify the evaluation of the propagation of gravitational waves in modified gravity. To do so, we use a concrete model which can be described as f(R) gravity with non-minimal coupling to matter. This is a model where the computation of an analytical expression for H(z) results impractical, but we find satisfactory results using the cosmography parametrization for the background. Whope that our findings will be relevant in the future for the evaluation of modified gravity models with a focus on gravitational waves.