Speaker:	Maëlie Mondelin (CEA) and Rodrigo Gonzalez Quaglia (Kavli IPMU)
Title:	Talk 1: Probing galaxy evolution in the cosmic web: from CFHT imaging of the Pisces–Perseus Supercluster to Euclid DR1, Talk 2: Cosmic Inflation: The Basics and Beyond
Date (JST):	Tue, Oct 20, 2026, 11:00 - 12:00
Place:	Seminar Room A
Abstract:	Speaker 1: Maelie Mondelin Title: Probing galaxy evolution in the cosmic web: from CFHT imaging of the Pisces–Perseus Supercluster to Euclid DR1 Abstract: Using deep CFHT/MegaCam imaging, I investigate how the cosmic web shapes galaxies across the nearby Perseus–Pisces supercluster (z = 0.017). I reconstruct its three-dimensional filamentary network to measure morphological and stellar mass segregation, and identify signatures of gravitational interactions across filaments, groups, and clusters. Massive early-type galaxies preferentially populate filament spines and dense nodes, while faint tidal disturbances reveal ongoing environmental processing. Beyond these population trends, I investigate intrinsic galaxy shape alignments using measurements extending from the inner stellar regions to low-surface-brightness outskirts. I find evidence for a late-type alignment signal, potentially providing the first observational indication of such an alignment. Late-type galaxies contributing most strongly to the shape–shape signal preferentially occupy filamentary regions, linking their orientation to their position within the cosmic web. These studies provide a pathfinder for environmental analyses in the Euclid DR1 footprint, particularly around the Horologium–Reticulum supercluster (z ≈ 0.06). I present preliminary morphological segregation measurements showing more pronounced changes in galaxy population fractions around groups and clusters than with filament distance, extending the nearby benchmark to a larger survey footprint. Speaker 2: Rodrigo Gonzalez Quaglia Title: Cosmic Inflation: The Basics and Beyond Abstract: In this talk, I will introduce the epoch of cosmic inflation, starting with its motivation from standard Big Bang cosmology to then discuss how it generates the primordial cosmological perturbations that seed the large scale structure of the universe. I will then review the current theoretical and observational status of inflation, highlighting some of the main constraints from cosmological observations and some of the open questions that remain. Finally, I will present a few ideas I explored during my PhD together with my current work, illustrating some of the approaches being explored to better understand the physics of inflation and its possible observational consequences.

← Back