Speaker:	Alessandro Manzotti (U Chicago)
Title:	The NeverEnding story of Cosmic Microwave Background and Large Scale Structure correlations
Date (JST):	Fri, Apr 24, 2015, 15:30 - 16:30
Place:	Seminar Room B
Abstract:	Gravitational lensing of the cosmic microwave background (CMB) by large scale structure is rapidly becoming both a useful tool for cosmology and a necessary component to model carefully in the statistical analysis of temperature and polarization anisotropy of the CMB. As an example of the first aspect I will show a novel technique to extract a sky map of the Integrated Sachs Wolfe (ISW) effect from CMB and large scale structure data. The ISW is a great probe of dark energy properties and a necessary step towards the understanding of possible large scale anomalies in the CMB. Regarding the second aspect I will cover two different effects of lensing on the CMB: the super sample covariance (SSC) and the distortion of polarization E modes into B modes. The first one consists of a dilation of intrinsic scales in the temperature and polarization fields due to the lensing of the CMB by modes that are larger than the size of the survey. This effect can be simply encapsulated as an additional parameter, the mean convergence in the field, for parameter estimation and will be important to precisely measure acoustic features deep into the damping tail with surveys covering less than 10% of sky. The second is now a source of confusion that begins to limit experiments that search for primordial B-mode polarization, and robust methods for delensing the CMB polarization sky are becoming increasingly important. I will investigate in detail the possibility of delensing the CMB with internally reconstructed lensing potential together with external tracers like the cosmic infrared background.

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