Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Numerical Methods in Gravitational Lensing   Most problems in gravitational lensing require numerical solutions. The most
frequent types of problems are (1) finding multiple images of a single source
and classifying the images according to their properties like magnification or
distortion; (2) propagating light rays through large cosmological simulations;
and (3) reconstructing mass distributions from their tidal field. This lecture
describes methods for solving such problems. Emphasis is put on using
adaptive-grid methods for finding images, issues of spatial resolution and
reliability of statistics for weak lensing by large-scale structures, and
methodical questions related to shear-inversion techniques.

12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con