Formerly known as the InitialConditionsSolver module of GRChombo (ascl:2306.039), the multigrid solver GRTresna solves the constraint equations for the initial data required in numerical relativity simulations. In particular, it focuses on scenarios with fundamental fields around black holes and inhomogeneous cosmological spacetimes. GRTresna makes use of the Chombo library (ascl:1202.008) for adaptive mesh refinement to allow automatic increasing of the grid resolution in regions of arbitrary shape and topology.

GRDzhadzha evolves matter on curved spacetimes with an analytic time and space dependence. Written in C++14, it uses hybrid MPI/OpenMP parallelism to achieve good performance. The code is based on publicly available 3+1D numerical relativity code GRChombo (ascl:2306.039) and inherits all of the capabilities of the main GRChombo code, which uses the Chombo library for adaptive mesh refinement.