This collaborative talk introduces the recent work in COSMO-3D group at EPFL’s Laboratory of Astrophysics (LASTRO). Jiaxi Yu (PhD student) will begin with a historical review of cosmology. The Universe started from a Big Bang, followed by inflation. The emission of the first light of the Universe, cosmic microwave background (CMB), happened in an opaque and dark era of the Universe afterwards. The Universe then transitioned to a matter-dominated era and is dominated by dark energy today. The first talk will explore how the evolution of cosmology mirrors these cosmic stages, from theories, observables to modern cosmological measurements.
Aurélien Verdier (PhD student) will introduce the 4-metre Multi-Object Spectroscopic Telescope (4MOST), a new high-multiplex, wide-field spectroscopic survey that will be conducted in Chile. The project is made of 18 different science cases, and its Cosmology Redshift Survey (CRS) will observe Bright Galaxies (BG) and Luminous Red Galaxies (LRG) at redshift 0.1<z<1.0. This presentation will focus on their target selection and their respective photometric systematics and clustering analysis.
Dr Rafaela Gsponer will discuss Early dark energy (EDE), a dark-energy-like component active in the early Universe that may resolve the Hubble tension. She will review the status of EDE studies and present her work on constructing an effective field theory-based approach to measuring EDE and exploring how high-redshift surveys like extended Bayon Oscillation Spectroscopic Survey (eBOSS) and Dark Energy Spectroscopic Instrument (DESI), can improve the EDE constraint.
Finally, Shengyu He (PhD student) will review pipelines to extract cosmological parameters from galaxy clustering of redshift surveys. That includes the fitting methods (ShapeFit, Full Modelling) and cosmological inference. He will also talk about the influence of spectroscopic systematics, a type of observational systematics from failed redshift measurements, on the clustering statistics and the constraints of cosmological parameters.
Host: Cheng Zhao
