Patrick Valageas web page

The images we receive on the Earth of distant galaxies are distorted by the deflections of light rays due to fluctuations of the gravitational potential along the line of sight. These stochastic perturbations lead to a shearing and magnification of distant sources which vary with the direction of observation on the sky. From the statistics of these distortions one can derive the statistical properties of the underlying density field. One advantage of this tool is that weak lensing effects directly probe the matter density field (dark matter and baryons) contrary to galaxy surveys which are sensitive to the distribution of light. This allows one to avoid the numerous uncertainties associated with the formation of stars.

Articles:

• 2004, submitted to MNRAS
  Measure of non-Gaussianities due to the non-linear gravitational dynamics from weak lensing surveys (cumulants and pdf).
  
• 2004, MNRAS, 350, 77 ,    2004, MNRAS, 347, 667 ,    2004, MNRAS, 347, 654 ,    2000, A&A, 364, 1 ,    2000, A&A, 356, 771
  Analytical description of the link between the statistics of weak gravitational lensing effects and the statistical properties of the underlying density field. Analytical models for their probability distributions.
  
• 2000, A&A, 354, 767
  Weak gravitational lensing effects on the determination of cosmological parameters from Type Ia supernovae.