Description
To include the full non-Gaussian information about cosmology and the
large-scale structure from measurements of weak gravitational lensing, one
needs to go beyond the second-order shear power spectrum. In my talk I will
then focus on weak-lensing peak counts, an indirect probe of the halo mass
function. I present a new fast and flexible model of peak counts. This model
allows us to use new statistical inference methods that do not require
assumptions about the functional form of the likelihood of the observables,
e.g. Gaussianity. In particular, I will present results using Approximate
Bayesian Computation (ABC), a new technique that has recently gained momentum
in the astrophysics community. I will show some results and forecasts how peak
counts can constrain dark energy and f(R) models.