PANDA, a Parametric N-body Code for Simulations of Horndeski Theories of Gravity
IFPU
April 27 – May 1, 2026
PANDA is a modified version of the Newtonian TreePM N-body solver Gadget-4 (Springel et al. [2021]) developed to simulate Modified Gravity models within Horndeski scalar–tensor theories (Horndeski [1974]) in a parametric way. In this project, we plan to significantly advance the implementation of PANDA, both from a theoretical and a computational perspective. Working together in the same place for a week will allow us to combine the expertise of all participants and achieve substantial improvements over the current state of the code. From the theoretical side, we expect to build a general implementation of Horndeski theories in both the linear and non-linear regimes, while we also aim to merge the Particle Mesh solver of PANDA with the relativistic and MG-compatible PM solver of MGevolution (Hassani and Lombriser [2020]), implemented by Dr. Farbod Hassani, thereby allowing us to include also relativistic effects in MG simulations and overcoming the Newtonian limit of the current PANDA implementation.
Participants:
- Marco Baldi (Bologna University)
- Farbod Hassani (Oslo University)
- Alessandro Casalino (Max-Planck Computing and Data Facility)
- Hans Arnold Winther (Oslo University)
- Edoardo Martinelli (Bologna University)