Speaker
Description
The standard $\Lambda$CDM model describes the evolution of the universe with remarkable success but relies on the enigmatic components of dark matter and dark energy. Recent cosmological tensions, such as the $S_8$ discrepancy, have further motivated the scientific community to perform stringent tests of General Relativity (GR) on large scales. Phenomenological modified gravity (MG) parameters, $\mu$ and $\Sigma$, offer a robust framework to detect potential deviations from GR and explore the nature of cosmic acceleration.
In this work, we present a comprehensive joint analysis pipeline that combines weak lensing measurements from the Subaru Hyper Suprime-Cam (HSC) Year 3 shape catalog with full-shape galaxy clustering from the SDSS BOSS DR12 catalog. To accurately model non-linear structure formation and redshift-space distortions (RSD) under modified gravity, we integrate the Lagrangian Perturbation Theory code, Velocileptors, with the Boltzmann solver MGCAMB. This theoretical framework allows for a sophisticated treatment of non-linear clustering while accounting for the unique gravitational interactions experienced by both light and matter.
For our statistical inference, we employ Cocoa, a highly scalable pipeline designed for future flagship surveys such as the Nancy Grace Roman Space Telescope. We detail the technical implementation of our MG-compatible joint analysis framework and present its validation.
Finally, we discuss the current status of our analysis, our methodology for mitigating modeling systematics, and the prospects for delivering new constraints on gravity from this cross-survey analysis.