Gravitational lensing of epoch-of-reionization gas

I present a weak lensing sensitivity estimate for upcoming high redshift (epoch of reionization and beyond) 21 cm surveys. Instruments such as PAST, LOFAR and SKA should be able to measure the weak lensing power spectrum to precisions far exceeding conceivable optical surveys. Three types of sources are detectable, which include the reionization Stromgren spheres, large scale structure, and minihalos. Tomography allows the measurement of the time evolution of the dark matter power spectrum. Raw sensitivities allow measurement of many cosmological parameters, including dark energy, neutrino mass and cosmic equations of state, to percent accuracy. It also has the potential for inflationary gravity wave measurements. Ultimate limits may be achievable through radio observations of 10(18) minihalos. Inflationary Hubble parameters H-1 down to 10(-9)M(Planck) can be detected through this effect. Second order effects may also be observable, allowing tests for backreaction and the quantum mechanical origin of perturbations. (C) 2004 Elsevier B.V. All rights reserved.