UK Cosmology Meeting

Session

Afternoon Session 2

25 Mar 2026, 15:40

Alan Heavens

11. Redshifts and physical properties of KiDS-1000 galaxies using the pop-cosmos galaxy population model

Anik Halder (University of Cambridge)

25/03/2026, 15:40

Accurate redshift estimation and physically motivated source sample selection are central challenges for precision weak lensing cosmology. In this talk, I will present our recent work on inferring physical properties of weak lensing galaxies in the Kilo-Degree Survey (KiDS-1000) using a generative model for the galaxy population. The framework enabling this work is pop-cosmos, a calibrated...

12. Constraining Momentum Exchange in the Dark Sector

Nathan Cruickshank (University of Portsmouth)

25/03/2026, 16:00

Interactions between dark energy and dark matter offer a potential solution to cosmological tensions. Specifically, models characterised by pure momentum exchange have been suggested to alleviate the S8 tension, as they lead to a suppression in structure growth rate at late times. In this talk, I will discuss how the choice of dark energy model impacts the ability of future data releases to...

13. Empirical dark matter halo profiles from weak lensing

Alicia Martin (Univerity of Oxford)

25/03/2026, 16:20

The structure of dark matter haloes is often described by radial density profiles motivated by cosmological simulations. These are typically assumed to have a fixed functional form (e.g. NFW), with some free parameters that can be constrained with observations. However, relying on simulations has the disadvantage that the resulting profiles depend on the dark matter model and the baryonic...

14. Searching for Cosmic (Super)strings in the CMB and the Stochastic Gravitational-Wave Background

Juhan Raidal (University of Nottingham)

25/03/2026, 16:40

Cosmic strings were once considered a leading candidate for the origin of cosmic structure, but high-resolution measurements of the cosmic microwave background (CMB) have ruled them out as the primary source of density fluctuations. Nevertheless, there remains ample room within the ΛCDM framework for the existence of cosmic strings or superstrings at subdominant levels. As these networks...