Lensing Effect on the Relative Orientation between the Cosmic Microwave Background Ellipticities and the Distant Galaxies

The low redshift structures of the Universe act as lenses in a similar way onthe Cosmic Microwave Background light and on the distant galaxies (say atredshift about unity). As a consequence, the CMB temperature distortions areexpected to be statistically correlated with the galaxy shear, exhibiting anon-uniform distribution of the relative angle between the CMB and the galacticellipticities. Investigating this effect we find that its amplitude is as highas a 10% excess of alignement between CMB and the galactic ellipticitiesrelative to the uniform distribution. The relatively high signal-to-noise ratiowe found should makes possible a detection with the planned CMB data sets,provided that a galaxy survey follow up can be done on a sufficiently largearea. It would provide a complementary bias-independent constraint on thecosmological parameters.Comment: 7 pages, 3 figures; uses emulateapj.sty; submitted to Ap