Balancing ACT: weighing prior dependency and global tensions of DR6 lensing with other datasets

We provide a complementary nested sampling analysis for the Atacama Cosmology Telescope lensing data release 6. This allows the quantification of global consistency statistics between ACT lensing and alternative datasets. In the context of flat $\Lambda$CDM, we find no inconsistency between ACT, Baryonic Acoustic Oscillations, Planck anisotropies, weak lensing datasets, or NPIPE lensing. As part of our analysis, we also investigate the effect of the prior widths used in the ACT analysis and find that the headline results are quantitatively but not qualitatively affected by the chosen priors. We use both Bayes factors and the suspiciousness statistic to quantify the possibility of tension, and find suspiciousness unsuitable in the case of strong agreement between ACT DR6 and NPIPE. Nested sampling provides a competitive alternative to Metropolis Hastings and we recommend it be used alongside existing analyses. We release the chains and plotting source for the analysis using anesthetic.