Personal tools
Log in
You are here: Home Research Activities Relativistic and Particle Astrophysics Physics of gravitation and cosmology with high precision space astrometry

Physics of gravitation and cosmology with high precision space astrometry

The improvement of the precision in the verification of General Relativity (GR) is of crucial importance for fundamental physics, having a cosmological and astrophysical impact on all scales. In fact, the study of the evolution of the Universe covering a timescale of 60 orders of magnitude, from the primordial to the present, depends essentially on the understanding of gravitational interaction, most reliably interpreted through General Relativity. The most used theoretical instrument to compare these theories on a local scale is the parameterized post Newtonian (PPN), in which each theory is characterised by precise assumed values from a parameter set estimated from experiments. Amongst these parameters, , (related to the curvature of space-time induced by mass) is the most studied, and also the most accessible via astrometric measurements. The estimation of this parameter allows tight constraints to be placed also on alternative formalisms that can appreciably modify the current estimate of the mass/dark energy ratio. In this sense the measurement of the parameter can be considered a powerful cosmological test using local measurements.

It is predicted that the GAIA mission can reach an accuracy of 10-6 for at the 3-sigma level, for nominal performance, by measuring the temporal evolution of the positions of a billion objects all over the celestial sphere. The numerical verifications and the relevant parts of the code are under development under an Agenzia Spaziale Italiana contract, coordinated with the activity of the European consortium DPAC (Data Processing and Analysis Consortium) for the reduction of GAIA data.

Light in Astronomy 2017

Nov 14, 2017

Light in Astronomy 2017 Light in Astronomy, organized by INAF in collaboration with the Italian Astronomical Society-SAIt, will be a week (13-19 November) dedicated to satisfying curiosity about the Universe thanks to the opening in Italy of INAF premises, including the astronomical observatories.

Marsis radar reveals that on Mars all that echoes is not ice

Oct 28, 2017

Marsis radar reveals that on Mars all that echoes is not ice The low dielectric constant of the Meridiani Planum deposits is consistent with a thick layer of ice-free, porous, basaltic sand. This study is fundamental to identify techniques that may help find the planet’s areas with accessible water ice.

A 3D step towards sorting out the Gamma-Ray Bursts zoo

Oct 13, 2017

A 3D step towards sorting out the Gamma-Ray Bursts zoo A powerful tool for characterizing and classifying gamma-ray bursts (GRBs) to allow their use as tracers of the expansion history of the universe has recently been presented by an international team of researchers led by Dr. Maria Dainotti