Relativistic angular redshift fluctuations
Deriving general-relativistic contributions and connections to CMB lensing and the integrated Sachs–Wolfe effect.
Research theme · 03
ARFs & missing baryons
Angular redshift fluctuations turn the mean redshift across the sky into a robust probe of cosmic velocities, gravity, and the diffuse gas between galaxies.
Angular redshift fluctuations (ARFs) complement galaxy number counts by tracing density and line-of-sight velocity while remaining resilient to important angular systematics. Their narrow redshift shells enable tomographic measurements of structure growth and tests of gravity.
Cross-correlating ARFs with cosmic-microwave-background maps also isolates the kinematic Sunyaev–Zel’dovich signal. This provides a redshift-resolved census of warm, diffuse intergalactic gas—including baryons that are difficult to detect through emission.
Selected work
Velocity fields as a cosmic map
Intergalactic gas from redshift 0 to 5
An 11σ ARF–kSZ detection tracing diffuse gas across most of cosmic history.
Tomographic constraints on gravity
Measuring structure growth in more than 20 redshift slices using BOSS galaxies.
A new cosmological observable
Introducing density-weighted ARFs as a systematic-resistant tracer of density and peculiar velocity.