Cosmological hydrogen recombination: Ly

We compute the corrections to the cosmological hydrogen recombination history due to delayed feedback of Lyman-series photons and the escape in the Lyman-continuum. The former process is expected to slightly delay recombination, while the latter should allow the medium to recombine a bit faster. It is shown that the subsequent feedback of released Lyman-n photons on the lower lying Lyman-$(n-1)$ transitions yields a maximal correction of $\Delta N_{\rm e}/N_{\rm e}\sim 0.22\%$ at $z\sim 1050$. Including only Lyman-β feedback onto the Lyman-α transition, accounts for most of the effect. We find corrections to the cosmic microwave background TT and EE power spectra with typical peak to peak amplitude $|\Delta C^{TT}_l/C^{TT}_l|\sim 0.15\%$ and $|\Delta C^{EE}_l/C^{EE}_l|\sim 0.36\%$ at $l\lesssim 3000$. The escape in the Lyman-continuum and feedback of Lyman-α photons on the photoionization rate of the second shell lead to modifications of the ionization history which are very small (less than $|\Delta N_{\rm e}/N_{\rm e}|\sim {\rm few}\times 10^{-6}$)