Release Announcement

Click here to read the announcement in HTML (with hyperlinks):
https://einsteintoolkit.org/about/releases/ET_2025_05_announcement.html

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, as well as stability and optimization improvements through
Simfactory.

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.

For more information about using or contributing to the Einstein
Toolkit, or to join the Einstein Toolkit Consortium, please visit our
web pages at http://einsteintoolkit.org, or contact the users mailing
list users@einsteintoolkit.org.

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 Einstein Toolkit contains about 400 regression test cases. On a
large portion of the tested machines, almost all of these tests pass,
using both MPI and OpenMP parallelization.

Contributors

Among the many contributors to the Einstein Toolkit and to this release
in particular, important contributions to new and existing components
were made by the following authors:

 * Cheng-Hsin Cheng
 * David Boyer
 * Deborah Ferguson
 * Erik Schnetter
 * Gabriele Bozzola
 * Hayley J. Macpherson
 * Ivan Markin
 * Leonardo Werneck
 * Liwei Ji
 * Lucas T. Sanches
 * Maxwell Rizzo
 * Miguel Zilhao
 * Peter Diener
 * Roland Haas
 * Samuel Cupp
 * Samuel Tootle
 * Steven R. Brandt
 * Terrence P. Jacques
 * Wolfgang Tichy
 * Yosef Zlochower
 * Yumeng Xu
 * Zachariah Etienne

How to upgrade from Cannon Release (ET_2024_11)

To upgrade from the previous release, use GetComponents with the new
thornlist to check out the new version.

See the Download page (http://einsteintoolkit.org/download.html) on the
Einstein Toolkit website for download instructions.

The SelfForce-1D code uses a single git repository; thus, using

git pull; git checkout ET_2025_05

will update the code.

To install Kuibit, do the following:

pip install --user -U kuibit==1.5.0

Machine notes

Supported (tested) machines include:

 * Debian, Ubuntu, Fedora, Mint, OpenSUSE, and macOS installations
   with dependencies installed as prescribed in the official
   installation instructions
 * Anvil
 * Deep Bayou
 * Delta
 * Expanse
 * Frontera
 * Queen Bee 3 and 4
 * Stampede 3
 * Sunrise
 * Supermike

Note for individual machines:

 * TACC machines: defs.local.ini needs to have `sourcebasedir =
   $WORK` and `basedir = $SCRATCH/simulations` configured for this
   machine. You need to determine $WORK and $SCRATCH by logging in to
   the machine.

All repositories participating in this release carry a branch ET_2025_05
marking this release. These release branches will be updated if severe
errors are found.

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