Campus, Varian 355
The Lyman-alpha forest (the correlated absorption seen in the spectra of high-redshift quasars) is a uniquely powerful probe of new physics in the cosmological model — whether that be properties of the neutrino, the nature of cosmic inflation or the phenomenology of dark matter. The challenge lies in robustly disentangling the cosmology and the astrophysics of the intergalactic medium from which it is sourced. I will discuss new models and methods that can achieve the statistical inference sufficiently accurate for current and upcoming spectroscopic surveys (e.g., eBOSS, DESI). These exploit the most sophisticated simulations of the Universe to-date and innovative machine-learning algorithms (Bayesian emulator optimisation). Deviation from the standard model of cold, collisionless dark matter would leave a characteristic suppression in the linear matter power spectrum that the Lyman-alpha forest can reveal. I will present preliminary bounds on the shape of this suppression and discuss the implications for the allowed range of dark matter candidates.