38 research outputs found
Cosmography via Gaussian Process with Gamma Ray Bursts
In this paper, we firstly calibrate the Amati relation (the correlation) of gamma ray bursts (GRBs) at low redshifts () via
Gaussian process by using the type Ia supernovae samples from Pantheon+ under
the philosophy that objects at the same redshift should have the same
luminosity distance in any cosmology. As a result, this calibration derives the
distance moduli of GRBs at high redshifts (). For an application of
these derived distance modulus of GRBs to cosmology, via Gaussian process
again, a series of cosmography parameters, which describe kinematics of our
Universe, up to the fifth oder and the redshift , i.e. the Hubble
parameter , the deceleration parameter , the jerk parameter ,
the snap parameter and the lerk parameter , are reconstructed from
the cosmic observations. The reconstructed cosmography parameters show a
transition singularity at , it may resort to two possible
explanations: one is that the GRBs data points at high redshift are still
reliable, it means that new physics beyond the CDM model happens;
another one is that the quality and quantity of GRBs data points at high
redshift are not good enough to give any viable prediction of the
kinematics of our Universe. To pin down this problem, more high redshifts
cosmic observational are still needed.Comment: 22 pages, 6 figures and 1 table. to appear in JCA