docs: rectangular mesh users must cite Enzi et al. 2026 (RTU grids)

docs/general/citations.md

@@ -72,6 +72,32 @@ also be cited:
 
 The package is available at <https://github.com/GragasLab/nufftax>.
 
+## Rectangular Mesh (Pixelized Reconstructions)
+
+If you reconstruct a galaxy using the adaptive rectangular meshes (`RectangularAdaptDensity` or
+`RectangularAdaptImage`), you **must cite** the following paper <https://arxiv.org/abs/2606.30620> under citation
+key `Enzi2026`. The mesh's adaptive coordinate transform implements the ray-guided transformed uniform (RTU)
+grid formulation this paper introduces, which is what makes the pixelization adaptive and fully
+auto-differentiable:
+
+```bibtex
+@article{Enzi2026,
+  author        = {Enzi, Wolfgang J. R. and Krawczyk, Coleman M. and Li, Tian and Collett, Thomas E.},
+  title         = {Gaussian processes on ray-guided transformed uniform grids for fast, flexible, and auto-differentiable adaptive source reconstruction in lens modelling},
+  journal       = {MNRAS, submitted},
+  eprint        = {2606.30620},
+  archivePrefix = {arXiv},
+  primaryClass  = {astro-ph.GA},
+  year          = {2026},
+  url           = {https://arxiv.org/abs/2606.30620},
+}
+```
+
+Note that **PyAutoGalaxy** pairs the RTU grid with its own regularization schemes (e.g. `reg.Constant`,
+`reg.Adapt`) rather than the Gaussian-process prior used in the paper, so quantitative results are not
+directly comparable between the two implementations. The `RectangularUniform` mesh performs no RTU transform,
+so this citation is not required when only the uniform mesh is used.
+
 ## Dynesty
 
 If you used the nested sampling algorithm Dynesty, please follow the citation instructions [on the dynesty readthedocs](https://dynesty.readthedocs.io/en/latest/references.html).

files/citations.bib

@@ -367,3 +367,14 @@ @article{dynesty4
 publisher={Zenodo},
 author={Sergey Koposov and Josh Speagle and Kyle Barbary and Gregory Ashton and Ed Bennett and Johannes Buchner
 and Carl Scheffler and Ben Cook and Colm Talbot and James Guillochon and et al.}, year={2023}, month={Jun} }
+
+@article{Enzi2026,
+  author        = {Enzi, Wolfgang J. R. and Krawczyk, Coleman M. and Li, Tian and Collett, Thomas E.},
+  title         = {Gaussian processes on ray-guided transformed uniform grids for fast, flexible, and auto-differentiable adaptive source reconstruction in lens modelling},
+  journal       = {MNRAS, submitted},
+  eprint        = {2606.30620},
+  archivePrefix = {arXiv},
+  primaryClass  = {astro-ph.GA},
+  year          = {2026},
+  url           = {https://arxiv.org/abs/2606.30620},
+}