Cosmic string lens effects on CMB polarization patterns

Extending the Kaiser-Stebbins mechanism we propose here a method for detecting relics of topological defects such as cosmic strings based on lens-induced small-scale B-type polarization in the cosmic microwave background. Models of inflation, in which large-scale structures of the Universe emerge from the inflaton fluctuations, do not exclude the formation of topological defects at the end of the inflationary phase. In such a case, we show that the lens effect of a string on the small-scale E-type polarization of the cosmic microwave background induces a significant amount of B-type polarization along the line of sight. The amplitude of the effect is estimated for different resolutions of cosmic microwave background experiments.