Kavli Institute for Particle Astrophysics and Cosmology, Stanford University and SLAC

Jared Siegel presents measurements that address two limitations of weak-lensing cosmology: intrinsic galaxy alignments and baryonic feedback. More than two million DESI galaxies and four lensing surveys provide alignment measurements across colour, luminosity, stellar mass and redshift. Combining Sunyaev–Zel’dovich profiles, eROSITA gas fractions and galaxy–galaxy lensing then constrains how feedback redistributes matter in groups and clusters at redshifts between zero and one. The results indicate stronger gas expulsion beyond virial radii than many simulations predict, reducing small-scale matter power. Incorporating these empirical constraints into cosmic-shear analyses improves cosmological inference. Online via Stanford KIPAC Zoom. Friday 9 October 2026, 10:40–11:30 PDT (America/Los_Angeles; UTC−7). Follow Join the zoom meeting on the official event page. The organizer lists faculty, staff, members and students as the audience. This listing advertises remote attendance.

Zack Gelles examines how black-hole rotation twists magnetic fields near light cylinders, where plasma accelerates into inflows and outflows. Semi-analytic models and simulations connect this structure to polarization changes detectable with radio interferometry, offering constraints on black-hole spin and relativistic jets. Kritti Sharma presents fast radio bursts as probes of cosmic baryons. Dispersion measures and secure host redshifts constrain gas in galaxy groups and clusters, while correlations with large-scale structure and other tracers map matter along burst sight-lines. The talk considers how future burst surveys can measure baryonic feedback and its evolution alongside other cosmological observations. Online via Stanford KIPAC Zoom. Friday 25 September 2026, 10:40–11:30 PDT (America/Los_Angeles; UTC−7). Follow Join the zoom meeting on the event page. The organizer lists faculty, staff, members and students as the audience. This is one session with two speakers; individual talk start times are not supplied.