Weak lensing the non-linear Lyα forest

ABSTRACT We evaluate the performance of Lyman α forest weak gravitational lensing estimator Metcalf et al. on data from hydrodynamic simulations and ray-trace simulated potentials. compare results to those obtained Gaussian random field Lyα potentials used in previous work. find that is able reconstruct more realistic investigate dependence spectrum signal noise. The non-linearity non-Gaussianity this arising instability hydrodynamics causes a reduction noise by factor ∼2.7 for free ∼1.5 spectra with order unity (comparable current observational data). Compared potentials, using ray-traced N-body incurs further signal-to-noise ∼1.3 at all levels. also observed increase bias reconstructed $5-25{{\ \rm per\ cent}}$, potential increases $20-30{{\ cent}}$. demonstrate methods mitigating these issues including Gaussianization correction which could be real observations.