PIRSA:25010065

Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure

Lamman, C. (2025). Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure. Perimeter Institute. https://pirsa.org/25010065

Lamman, Claire. Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure. Perimeter Institute, Jan. 07, 2025, https://pirsa.org/25010065 

          @misc{ pirsa_PIRSA:25010065,
            doi = {10.48660/25010065},
            url = {https://pirsa.org/25010065},
            author = {Lamman, Claire},
            keywords = {Cosmology},
            language = {en},
            title = {Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure},
            publisher = {Perimeter Institute},
            year = {2025},
            month = {jan},
            note = {PIRSA:25010065 see, \url{https://pirsa.org}}
          }

Claire Lamman

Harvard University

Talk number
PIRSA:25010065
Collection
Talk Type
Subject
Abstract

Gravitational forces from the largest structures in the Universe leave a detectable imprint on galaxies and their local environment. I will present a new approach to tracing the tidal field using these correlations: the intrinsic alignment of small groups of galaxies, or "multipelts". Multiplets mostly consist of 2-4 galaxies within 1 Mpc/h of each other, and we measure their orientations relative to the galaxy-traced tidal field. Using spectroscopic redshfits from the DESI Y1 survey, we detect intrinsic alignment out to projected separations of 100 Mpc/h and beyond redshift 1. We find a simillar signal regardless of galaxy luminosity or color, which could make multiplet alignment a useful tool for mapping the direction of the tidal field and any cosmological effects which impact it. Our detection demonstrates that galaxy clustering in the non-linear regime of structure formation preserves an interpretable memory of the large-scale tidal field.