We show how kSZ tomography measures a bispectrum containing a cosmological power spectrum of the velocity field and an astrophysical power spectrum of the electron density. While these are degenerate up to an overall amplitude (the "galaxy optical depth"), scale-dependent effects on large scales are much better constrained by the inclusion of kSZ on top of galaxy clustering while assuming nothing about the optical depth of galaxy clusters.

Extracting cosmological information from current survey data is increasingly reliant on computationally-intensive n-body simulations of large-scale structure. For weak-lensing surveys, the matter distribution is directly measured from simulations on scales where linear perturbation theory fails. For galaxy-clustering surveys, haloes are identified in simulations and then populated with galaxies to provide mock catalogues.

The Wide Field Infrared Survey Telescope (WFIRST) is an upcoming NASA observatory that will investigate the origins of cosmic acceleration using weak gravitational lensing.  WFIRST will perform galaxy shape measurements using Teledyne H4RG-10 detectors; thus it is essential to understand inter-pixel non-linear effects like the brighter-fatter effect (BFE) and non-linear inter-pixel capacitance (NL-IPC) that could cause systematic errors in the lensing analysis.  The

On April 10, 2019, the Event Horizon Telescope (EHT), a very long baseline interferometry experiment, released the first image of a black hole resolved to event horizon scales. I will discuss the image of M87 and aim to convince the audience that a flux depression in the image is necessary to fit the data. I will also discuss the parameters we derived based on the image and model fitting results.

The kinematic Sunyaev-Zel'dovich effect enables us to directly probe the density-weighted velocity field up to very large cosmic scales. We investigate the effects of intrinsic alignments (IA) of dark-matter halo shapes on cosmic density and velocity fields on such large scales. In literature IA have been detected with the halo density field up to ~ 100 Mpc/h both in simulations and observations.

The standard cosmological paradigm, wherein luminous galaxies trace the underlying cosmic web of dark matter, reproduces a wide variety of large-scale observations spectacularly well.  However, basic questions remain within the model, including the nature of dark matter and of the small-scale physics that are important to galaxy formation.  Our cosmic neighborhood, the Local Group (LG), is one of the best laboratories for answering these vital questions, largely because tiny, faint dwarf gala

Investigating the clustering of halos and galaxies helps us learn about cosmology and galaxy formation physics. The clustering of dark matter halos is found to depend on not only halo mass but also halo properties related to their formation history or environment, which is called halo assembly bias.