Speaker
Description
We apply an extended Alcock–Paczyński (AP) test to the SDSS data to constrain the dark energyequation of state with the Chevallier–Polarski–Linder (CPL) parametrization. The extended AP test method uses the full shape of redshift-space two-point correlation funcion (CF) as the standard shape in order to measure the expansion history of the universe. We calibrate the standard shape by using the cosmology-dependent nonlinear evolution of the CF shape in the Multiverse simulations. Further validation of the method and calibration of possible systematics are performed based on mock samples from the Horizon Run 4 simulation. Using the AP test alone, we constrain the flat CDM plus CPL-type dark energy model (flat wCPLCDM) to have Wm=0.289_-0.029^+0.031, w_0=-0.798_-0.102^0.192 and w_a=-0.165_-0.945^+0.610. The result does not show evidence for a dynamically evolving dark energy model. When combined with other results from the low-redshift universe, such as the PantheonPlus supernova compilation and DESI BAO data, the constraint on w_a becomes w_a=-0.124_-0.368^+0.334, which is still consistent with zero.
