Conveners
Cosmology 6
- Kwan Chuen Chan (Sun-Yat Sen University)
Description
systematics
DESI DR1 full-shape clustering constrains cosmology from linear to quasi-nonlinear scales but is vulnerable to projection effects from broad nuisance priors. We strengthen the analysis along three axes: (i) HOD-informed priors (HIP), calibrated on high-fidelity mocks, to anchor nuisance parameters to realistic galaxy–halo connections; (ii) nonlinear reparameterization of the nuisance sector...
Primordial non-Gaussianity is one of the most important signals for probing the physics of the early universe. Over the past decade, constraints on primordial non-Gaussianity (quantified by the parameter fNL) from the Planck experiment have ruled out a number of simple inflationary models. In the coming years, ongoing and upcoming large-scale structure (LSS) surveys (e.g., SPHEREx) will...
The accurate determination of the true redshift distributions in tomographic bins is critical for cosmological constraints from photometric surveys. We developed a redshift self-calibration method, which utilizes the photometric galaxy clustering alone, is highly convenient and avoids the challenges from incomplete or unrepresentative spectroscopic samples in external calibration. By refining...
Stage IV surveys such as Euclid and LSST will have unprecedented constraining power in cosmological parameters. To achieve this scientific goal, one of the major sources of uncertainties, photometric redshifts of the galaxy sample, needs to be under control. Clustering redshift has been a promising method for photometric redshift calibration, as have been adopted in many stage III surveys, but...
Photometric galaxy surveys, despite their limited resolution along the line of sight, encode rich information about the large-scale structure (LSS) of the Universe thanks to the high number density and extensive depth of the data. However, the complicated selection effects in wide and deep surveys can potentially cause significant bias in the angular two-point correlation function (2PCF)...
We investigate the possibility of using the cosmic gravitational focusing (CGF) to probe the minor light dark matter (DM) component whose mass is in the range of $(0.1 \sim 100)$\,eV. Being a purely gravitational effect, the CGF offers a mode-independent probe that is complementary to the existing ways such as Lyman-$\alpha$ and $\Delta N_{\rm eff}$. Such effect finally leads to a dipole...
