Will Dawson

UC Davis

Gravitational Weak Lensing Tomography and Examples of its Application



Gravitational weak lensing has been proven an indispensable cosmological probe.  However, it is often not used to its full effectiveness. Since the magnitude of the weak lensing signal not only depends on the mass of the lens but also the relative distances between the observer, the lens, and the source, the amplitude of the shear signal as a function of redshift contains information about the three dimensional structure.  Most analyses to date discard this information. However, as I will show, this dependence on cosmic distances can be used to constrain cosmological parameters, estimate the redshifts of mass concentrations, determine the fraction of catastrophic photometric redshift errors in a survey, identify line-of-sight structures (which may otherwise bias mass measurements), and construct a signal-matched filter for improved weak lensing mass estimates.  I will follow this up by presenting results from some of our recent applications of weak lensing tomography to a potential “bullet-like” cluster and cosmic filaments.