Anisotropies of the cosmic background radiation by domain wall networks

We discuss cosmological effects by domain wall formation associated with a late time phase transition after decoupling. Assuming the existence of rigid domain wall networks, we construct a simple one-dimensional model and calculate the quadrupole anisotropy of the cosmic background radiation (CBR). Contrary to one's naive expectation, the gravitational potential of a domain wall itself does not disturb the isotropy of CBR. Estimating the quadrupole anisotropy of CBR induced by the wall driven growth of matter density perturbations, a 100h^-1 Mpc periodic wall structure is found to be consistent with the observed upper bound.