Topic: weak lensing

Baryonic feedback introduces substantial uncertainty into cosmological inference from weak lensing. Henry Liu presents measurements of radial gas fractions around DESI galaxies that avoid assuming parametric gas profiles. The method combines galaxy-galaxy lensing with the kinematic Sunyaev–Zel’dovich effect, using a modified kSZ filter matched to the lensing delta-Sigma observable to estimate gas fractions directly. The analysis joins DESI DR2 Bright Galaxy Survey and luminous-red-galaxy samples with ACT DR6 microwave-background maps and HSC Y3 shear data. Gas fractions are suppressed at smal

Biwei Dai explores generative models built around physical symmetries and multiscale structure. For cosmology, these models enable field-level likelihoods that extract more information from weak lensing than two-point statistics and expose model misspecification through generated samples. Related methods address lattice sampling and collider anomalies. Physically informed generative priors also support inverse problems, including intensity-interferometry reconstruction of black-hole accretion disks and analysis of pulsar-timing gravitational-wave backgrounds.