We consider flat universes with nonzero cosmological constant (Lambda) and study the temperature anisotropies caused by microwave photons affected by gravitational lensing. We study the lensing effect produced by linear density fluctuations present from recombination to now. The result is that, for the cold dark matter model, the dispersion of the gravitational deflections decreases with Lambda. Considering that scenario with two values of Omega(0), 0.2 and 1, we calculate the effect of bending on measurements of small-scale experiments, finding that the enhancement of the temperature anisotropies measured in a flat universe with nonzero Lambda is slightly lower than the one measured in a flat universe with zero cosmological constant.

Peer reviewed