Fundamental physics with the Lyman-alpha forest: constraints on the growth of structure and neutrino masses from SDSS with effective field theory

We present an effective field theory (EFT) approach to extract fundamental cosmological parameters from the Lyman-alpha forest flux fluctuations as an alternative to the standard simulation-based techniques. As a first application, we re-analyze the publicly available one-dimensional Lyman-alpha flux power spectrum (FPS) data from the Sloan Digital Sky Survey (SDSS). Our analysis relies on informative priors on EFT parameters which we extract from a combination of public hydrodynamic simulation and emulator data. Assuming the concordance cosmological model, our one-parameter analysis yields a $2%$ measurement of the late time mass fluctuation amplitude σ₈ = 0.841± 0.017, or equivalently,the structure growth parameter S₈ = 0.852± 0.017, consistent with the standard cosmology. Combining our EFT likelihood with Planck + baryon acoustic oscillation data, we find a new constraint on the total neutrino mass, ∑ m_ν< 0.08 eV (at 95% CL). Our study defines priorities for the development of EFT methods and sets the benchmark for cosmological analyses of the Lyman-alpha forest data from the Dark Energy Spectroscopic Instrument.