2-point correlation functions

cBalls can compute 2-point correlations (2pcf) when counts (N) or a scalar field are involved (like convergence K):

NN:

It is the normal 2-point correlation function of number counts (typically galaxy counts).

KK:

So far we have consider that the scalar field is the convergence in weak lensing \(\kappa\). Then this gives the 2-point kappa-kappa correlation function.

N represent simple counting and K represent a real scalar field, like convergence in weak lensing.