Polarization of the CMB cold spot by the gravitational lensing of a cosmic void and texture

Abstract

The cold spot is one of the observed CMB anomalies proposed to be produced by various primary and secondary effects. In this work, we study the gravitational lensing of some of the candidates that could produce the cold spot, namely a huge void and a cosmic texture, on the various components of CMB random field. Our results demonstrated that the signal to noise ratio of gravitational lensing effect on the CMB temperature field is higher than that of on CMB polarization. We found that for a cylindrically symmetric void at z_Void=0.8 with σ=-1.0 a thousand minute observation would detect the gravitational lensing signal while for a cosmic texture at z_Texture=6.0 a longer observation is required. We expect the future high resolution surveys can put strong constraints on the amplitudes of the template of these models.

Keywords

• cmb stochastic field
• gravitational lensing
• likelihood analysis