We are pleased to announce the thirtieth release (code name “Martin D. Kruskal”) of the Einstein Toolkit, an open-source, community-developed software infrastructure for relativistic astrophysics. The major changes in this release include:
One new thorn has been added:
* CCE_Export — This thorn provides output support for data to be used in the “SpECTRE Cauchy-characteristic evolution” code to extract waveforms at infinity.
Updated thorns:
* CarpetX — Further updates and new functionality.
* Derivs — Add support for 6th and 8th order accurate finite differencing.
* FLRWSolver — This thorn provides cosmological initial conditions based on a Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime, either with or without small perturbations.
Along with one new gallery example:
* Black-hole hair in axi-dilaton gravity — Evolving a single black hole under modified axi-dilation gravity.
In addition, bug fixes accumulated since the previous release have been included.
The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. It builds on numerous software efforts in the numerical relativity community, including codes to compute initial data parameters, the spacetime evolution codes Baikal, lean_public, and McLachlan, analysis codes to compute horizon characteristics and gravitational waves, the Carpet AMR infrastructure, and the relativistic (magneto)hydrodynamics codes GRHayLHD, GRHayLHDX, GRHydro, and IllinoisGRMHD. Data analysis and post-processing are handled by the kuibit library. The Einstein Toolkit also contains a 1D self-force code. For parts of the toolkit, the Cactus Framework is used as the underlying computational infrastructure, providing large-scale parallelization, general computational components, and a model for collaborative, portable code development.
The Einstein Toolkit uses a distributed software model. Its different modules are developed, distributed, and supported either by the core team of Einstein Toolkit Maintainers or by individual groups. Where modules are provided by external groups, the Einstein Toolkit Maintainers ensure quality control for modules included in the toolkit and help coordinate support. The Einstein Toolkit Maintainers currently involve staff and faculty from five different institutions and host weekly meetings that are open to anyone.
Guiding principles for the design and implementation of the toolkit include: open, community-driven software development; well thought-out and stable interfaces; separation of physics software from computational science infrastructure; provision of complete working production code; training and education for a new generation of researchers.
The Einstein Toolkit is primarily supported by NSF 2004157/2004044/2004311/2004879/2003893/2114582/2227105 (Enabling fundamental research in the era of multi-messenger astrophysics).
The “Martin D. Kruskal” Release Team on behalf of the Einstein Toolkit Consortium (2025-05-29)
Maxwell Rizzo, Roland Haas, Bing-Jyun Tsao, Deborah Ferguson, Hayley J. Macpherson, Leonardo Werneck, Lucas Timotheo Sanches, Peter Diener, Steven R. Brandt, Zachariah Etienne
May 29, 2025