Free use
Licences
Everything made in this project can be used in any way — copied, modified, published, sold — without permission and without mandatory attribution.
© 2026 Sergey Ivliev.
| What | Licence | Conditions |
|---|---|---|
Code: the pbhgr library (Python and C), scripts, tests, the sphdiag module |
MIT-0 (MIT No Attribution) | none |
| The 3D modules PBHVlasov (for GRTeclyn) and PBHCosmo (for GRChombo) | BSD-3-Clause (PBHVlasov, PBHCosmo) | keep the copyright notices and the licence text |
| Site texts, documents and their translations, the computation log and its translation, figures, the long read, the 3D visualisation, the video (picture, text and subtitles) | CC0 1.0 — public domain dedication | none |
| Run outputs (the Data section) | CC0 1.0 | none |
Why the 3D modules are BSD-3-Clause rather than MIT-0. They are built on, and partly derived from, GRChombo (© 2018 GRChombo) and GRTeclyn (© 2022 The GRTL Collaboration). Those codes' licence requires keeping their copyright notices, so we cannot drop that condition. In every other respect BSD-3-Clause is just as free: you may use, modify and sell.
Not ours, and not covered by these licences:
- the video narration is synthesised with ElevenLabs; use of the audio track is subject to ElevenLabs' terms (the picture, text and subtitles are CC0);
- quotations from third-party papers in the literature audits belong to their authors;
- the Onest, Unbounded, JetBrains Mono and Inter fonts are under the SIL Open Font License 1.1; three.js, KaTeX and Pagefind are under the MIT licence;
- external codes such as GRChombo, GRTeclyn, AMReX, Chombo, numpy and scipy keep their own licences.
How to cite
Attribution is not required, but a citation is appreciated in research use:
Sergey Ivliev, "PBHs before reheating: numerical relativity of primordial black hole formation in an early matter era", https://pbh.ivliev.org (2026).
The pbhgr archive contains a CITATION.cff file; both archives contain LICENSE and LICENSING.md with the details. The archives are on the Code page.