A Simple and Practical Algorithm for Accurate Gravitational Magnification Maps

TL;DR

This paper presents a straightforward, practical algorithm for generating accurate gravitational magnification maps using a first-order approximation of null geodesic paths, simplifying the modeling process.

Contribution

It introduces a simple, explicit method for calculating magnification patterns with a transparent algorithm and provides a Matlab implementation for multiple point lenses.

Findings

Efficient computation of magnification maps using first-order approximation.

The algorithm is simple, transparent, and adaptable for multiple lenses.

Provides a practical tool for gravitational lensing studies.

Abstract

In this brief communication a new method is outlined for modelling magnification patterns on an observer's plane using a first order approximation to the null geodesic path equations for a point mass lens. For each ray emitted from a source, an explicit calculation is made for the change in position on the observer's plane due to each lens mass. By counting the number of points in each small area of the observer's plane, the magnification at that point can be determined. This allows for a very simple and transparent algorithm. A short Matlab code sample for creating simple magnification maps due to multiple point lenses is included in an appendix.