Weak Gravitational Lensing of Large Scale Structures

Weak gravitational lensing refers to very small distortions of images of background sources (for example galaxies) near a foreground mass (an object which lie between the source and the observer). This effect is studied through coordinate transformation which relates the source coordinate to image coordinate. The derivatives of this transformation is decomposed into trace (convergence) and trace-free part (shear). The trace part magnifies the background sources by increasing their size, and the trace-free part stretches them tangentially with respect to the foreground mass. This book aims to go beyond the usual point source approximation to study the effect of lensing of light from a finite source, which corresponds to lensing of the large scale structures in the universe