LARGE-SCALE PECULIAR VELOCITY-FIELD DUE TO INFINITELY LONG COSMIC STRINGS

We investigate the large-scale peculiar velocity field of dark matter due to the wakes formed by infinitely long cosmic strings. The peculia r velocity due to such strings, which passed through at the stage 1 z(i) is solved analytically for one-dimensional case, including the co ntribution of the background radiation density. The three dimensional large-scale peculiar velocities will be the vector sum of such velocit ies, and the root mean square (rms) peculiar velocities can be estimat ed. The large peculiar velocity of the Local Group (congruent-to 600 k m s-1) and the distribution of peculiar velocities for nearby 20 clust ers of galaxies can be explained by adopting the parameter Gmubetagamm a(n)1/2 congruent-to (4 +/- 1) x 10(-6), where mu and beta are the lin e density and the velocity of a cosmic string in units of c = 1 and ga mma = (1 - beta2)-1/2. The parameter n denotes the number of infinitel y long cosmic strings per horizon passed through in each e-time expans ion of the universe.