3 research outputs found
Updated F(T) gravity constraints from high redshift cosmography
In the last dozen years a wide and variegated mass of observational data
revealed that the universe is now expanding at an accelerated rate. In the
absence of a well-based theory to interpret the observations, cosmography
provides information about the evolution of the Universe from measured
distances, only assuming that the geometry of the can be described by the
Friedmann-Lemaitre-Robertson -Walker metric. We perform a high-redshift
analysis allows us to put constraints on the cosmographic parameters up to the
5fth order, thus inducing indirect constraints on any gravity theory. Here we
are interested in the so called teleparallel gravity theory, f(T). Actually we
use the analytical expressions of the present day values of f(T) and its
derivatives as functions of the cosmographic parameters to map the cosmography
region of confidences into confidence ranges for f(T) and its derivative.
Moreover, we show how these can be used to test some teleparallel gravity
models without solving the dynamical equations. Our analysis is based on the
Union2 Type Ia Supernovae (SNIa) data set, a set of 28 measurements of the
Hubble parameter, the Hubble diagram constructed from some Gamma Ray Bursts
(GRB) luminosity distance indicators, and gaussian priors on the distance from
the Baryon Acoustic Oscillations (BAO), and the Hubble constant h. To perform
our statistical analysis and to explore the probability distributions of the
cosmographic parameters we use the Markov Chain Monte Carlo Method (MCMC).Comment: International Journal of Modern Physics D, 20 pages, 5 figure
Updated f(T) gravity constraints from high-redshift cosmography
In the last dozen years, a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides information about the evolution of the universe from measured distances, only assuming that the geometry can be described by the Friedmann\u2013Lemaitre\u2013Robertson\u2013Walker metric. In this paper, we perform a high-redshift analysis which allows us to put constraints on the cosmographic parameters up to the fifth-order, thus inducing indirect constraints on any gravity theory