Astrophysics Colloquium - New imprints of large-scale structure on the CMB

Gravitational lensing makes the Cosmic Microwave Background non-Gaussian and allows the reconstruction of
projected matter fluctuations; the Integrated Sachs-Wolfe effect modifies the CMB temperature in a way
that depends on the growth rate of matter perturbations. Both of these effects become more informative
when performed tomographically: using cross-correlation with galaxy catalogues to pull out the low-redshift 
part of the lensing and ISW signals. I will present new tomographic results using ACT CMB maps, and 
discuss the implications of CMB lensing tomography in the context of recent claims from DESI that the
dark energy density evolves. I will then explain a novel technique that probes the alignment of dipoles 
in foreground signals with the peculiar velocity field, presenting a new signature of the ISW effect.