(Received September 4, 1990)
First we derive the gravitational deflection angle of light rays passing through a disk consisting of pressureless matter, and show that it behaves like a convex lens. Next we derive the two-ray difference of deflection angles by help of the Raychaudhuri equation, in the cases when the wall-like objects are dust walls and domain-walls. Moreover we derive the two-ray difference of deflection angles in a low mass-density region lying between wall-like objects. It is shown that this region plays a role of a concave lens and its effect is comparable with the effects of wall-like objects. On the basis of these deflection angle differences, we consider the gravitational lens effect of uniform wall-like objects which may exist homogeneously on the cosmological scale. Under the condition that rays pass always through the inner regions of wall-like objects, we show that the convex lens effect is dominant and in a case when the wall-like objects appear at the epoch of z = 5, the measured angles of the cosmic background radiation may increase about 2.0 and 1.1 times owing to the integrated convex lens effect for dust walls and domain-walls, respectively. If the above condition is not satisfied, gravitational lens effect due to wall-like objects is negligibly small.
URL : http://ptp.ipap.jp/link?PTP/85/57/
DOI : 10.1143/PTP.85.57