Reproducibility archive: complementary nanohertz constraints on the graviton mass from the spectral cutoff of the NANOGrav 15-year and EPTA DR2 gravitational-wave backgrounds

Code and data products that reproduce every figure and numerical result of the manuscript 'Complementary nanohertz constraints on the graviton mass from the spectral cutoff of the NANOGrav 15-year and EPTA DR2 gravitational-wave backgrounds' (S. Gaudio). Contents: the cutoff likelihood and Metropolis-Hastings sampler (prod_lib.py); the production MCMC chains (EPTA DR2full+, NG15, indicative combination, the prior-variant chains with lower edges -24/-26, and the emcee cross-check chains); the reconstructed EPTA and NG15 free-spectral KDE data products; the figure generators; and the validation scripts. Everything is built from the public NANOGrav 15-year ceffyl posteriors (Zenodo 8067506) and EPTA DR2 free-spectral chains (Zenodo 8091568). The ~275 MB of raw EPTA chains are not redistributed here; the included KDEs suffice to reproduce all results. See README.md for a manifest and a 'which script makes which figure/number' table.