I will start with a short introduction to Bayesian statistics, including the magic of Markov chain Monte Carlo. With these concepts, I will describe how to build and use an emulator, a fast statistical approximation to a computationally intensive simulation. I will present this in the context of the Cosmic Emu, an emulator for the matter power spectrum based on large n-body simulations.

Gravitational lensing of the cosmic microwave background (CMB) has emerged as a powerful cosmological probe, made possible by the development and characterization of nearly-optimal estimators for extracting the lensing signal from temperature and polarization maps. One can ask whether similar tools can be applied to upcoming "intensity maps" of emission lines at various wavelengths (e.g. 21cm).

Finding direct evidence of Primordial Gravitational Waves (PGWs) is one of the most exciting and important goals in fundamental physics today. The polarized light of the Cosmic Microwave Background (CMB) provides a powerful dataset from which we may detect PGWs and draw quantitative conclusions about the early Universe.

The quenching "maintenance" and related "cooling flow" problems are important in galaxies from Milky Way mass through clusters. We investigate this in halos with masses ~1e12-1e14 solar mass, using non-cosmological high-resolution hydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model.

Since the first detection two years ago, gravitational waves have promised to revolutionize the physics and astrophysics of compact objects.

Strong dark matter interactions are proposed to alleviate the tension between observations and theoretical predictions in CDM. Among different interaction channels, self-interacting dark matter (SIDM) models have received considerable attention.

Large scale structure leaves an imprint in the cosmic microwave background (CMB) in the form of secondary anisotropies.  As a result of these small distortions, CMB and galaxy surveys provide highly complementary cosmological probes.  I will illustrate how this complementarity can be exploited using cross-survey correlations between galaxy surveys and (i) CMB lensing and (ii) the Sunyaev-Zel’dovich effect.  Moreover, the complementarity of CM

On March 1st, the EDGES collaboration reported the detection of a sharp absorption signal in the all-sky radio spectrum at ~80 MHz. This frequency is roughly consistent with early theoretical predictions for the global 21-cm signal, a sky-averaged spectral signature of neutral hydrogen atoms in the intergalactic medium before cosmic reionization.