Cosmic (Super)String Constraints from 21 cm Radiation

We calculate the contribution of cosmic strings arising from a phase transition in the early Universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z≥30. Future experiments can exploit this effect to constrain the cosmic string tension Gμ and probe virtually the entire brane inflation model space allowed by current observations. Although current experiments with a collecting area of ∼1  km² will not provide any useful constraints, future experiments with a collecting area of 10⁴–10⁶  km² covering the cleanest 10% of the sky can, in principle, constrain cosmic strings with tension Gμ≳10^-10–10^-12 (superstring/phase transition mass scale >10¹³  GeV).