Mapping Dark Matter via Gravitational Lensing

CosmoAI-AES is an inter-disciplinary research group at the Department of ICT and Natural Sciences at NTNU in Ålesund, working on gravitational lensing.

• Professor Hans Georg Schaathun is a computer scientist working on simulation and machine learning
• Dr Ben David Normann is a mathematical physicist working on cosmology

These pages present prototypes for two pieces of software.

• CosmoSim is a simulator of gravitational lensing, supporting both an interactive and graphical user interface, and a command line interface for bulk generation of images.
• droulette is not publicly available as of March 2026, but will be made public in the future. It provides the plumbing code to apply machine learning to images from CosmoSim.

Using CosmoSim

• Installation CosmoSim is a Python Package and can be installed with pip install CosmoSim.
• CosmoSim GUI, which is run as python -m CosmoSim.GUI.
• Machine Learning Pipeline with droulette
• User Tools for command line operation.

Technical Documentation

• Test Scripts
• Software Model - technical documentation
• Simulation Model - technical documentation of the simulator library
  • Raytrace Simulation
  • Roulette Simulation (Overview)

The Mathematics of CosmoSim

• Basic Notation
  • LensPotential
  • Critical Curves
• Roulette formulæ
• Lens Models
• PointMassCloud (in progress)

Development

• Release Process
• Workflows in github

Publications

If you build on our work, please cite one of our [[Publications]].

1. Hans Georg Schaathun, Ben David Normann, and Kenny Solevåg-Hoti. Om å kartleggja mørk materie med maskinlæring. In Norsk IKT-konferanse for forskning og utdanning, number 1, 2023.
2. Hans Georg Schaathun, Ben David Normann, Einar Leite Austnes, Simon Ingebrigtsen, Sondre Westbø Remøy, and Simon Nedreberg Runde. On the simulation of gravitational lensing. In Enrico Vicario, Romeo Bandinelli, Virginia Fani, and Michele Mastroianni, editors, Proceedings of the 30th European Conference on Modelling and Simulation. ECMS - European Council for Modelling and Simulation, 2023. Florence, Italy, 21-23 June 2023.