337 F(e) = (z) where the angle between the directions III and 112 is equal to 8. r is the angular diameter effective distance of the epoch for recombination. F (8) ve have F(e): f (e) (S" ) e. . is a Bessel function. It is assumed here that the spectrum of gravitational waves takes the form 1 hI'::: hoK for all relevant wavelengths, a is beam width of the radio antenna, d= d, and is the duration of the process of recombinations in -time. The results for different beam widths are shown in Fig. 1. 338 I. D. NOVIKOV 1-. . . -__ 0. 5 1 1. 5 2 e' 0. 5 o and for a l' (solid line) and Fig. 1. The...