A new smoothing algorithm and its application in gravitational lensing

Artikel i vetenskaplig tidskrift, 2008

We develop a new smoothing algorithm for computing surface densities from 3D numerical simulation samples. This algorithm is based on DWT (discrete wavelet transform) method. We test the algorithm by applying it to two gravitational lensing simulation samples which are generated by monte-carlo method and have different mass resolution, the results show our algorithm can successfully reconstruct the surface density of lens. We also compute the critical curves and caustics of lens samples, the results show that they can fit the theoretic curves very well. We test three different wavelet bases and compare them, including Daub4, Daub6 and B-spline 3th. Our algorithm is very fast and is suitable for high resolution N-body simulations.