docs: correct sigma_LT/sigma_0 attribution in dPIE docstrings - #525
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The sqrt(3/2) relation between Lenstool's fiducial dispersion (sigma_LT) and the central dispersion (sigma_0) was attributed to Elíasdóttir et al. (2007) as if it were that paper's physical definition. Per the contributed derivation note (H. Ding 2026, "On the definitions of b0 and velocity dispersion in Lenstool / dPIE"), it is Lenstool's parameter convention: Lenstool computes b0 = 6*pia_c2*sigma^2 (an E07-style coefficient) but evaluates deflections with the Kassiola & Kovner (1993) / Limousin et al. (2005) amplitude, so the input sigma must be read through the L05 parameterization. Docstrings now state this, and give the equivalent central-dispersion form b0 = 4*648000*(sigma_0/c)^2*(D_LS/D_S). No numerical behaviour changes — documentation only; the sigma_LT parameterization is retained deliberately for Lenstool results-table parity. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012Eacj9naBWSKrevsqnVJWR
…e to References Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012Eacj9naBWSKrevsqnVJWR
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Documentation-only correction to the dPIE mass-profile docstrings, from the contributed derivation note (H. Ding 2026, "On the definitions of b0 and velocity dispersion in Lenstool / dPIE"):
sigma_0 = sqrt(3/2) * sigma_LTwas attributed to Elíasdóttir et al. (2007) as a physical definition. It is in fact Lenstool's parameter convention — an E07-styleb0coefficient paired with the Kassiola & Kovner (1993) / Limousin et al. (2005) deflection amplitude — and the docstrings (dPIEMass,from_lenstool,_b0_from_lenstool_sigma) now say so consistently.b0 = 4 * 648000 * (sigma_0/c)^2 * (D_LS/D_S)and the derivation note to the References block.No numerical behaviour changes; the
sigma_LTparameterization is retained deliberately for Lenstool results-table parity. Reviewed by an Opus pass (no blockers; its one finding — a stale attribution left in the helper docstring — is fixed here).🤖 Generated with Claude Code
https://claude.ai/code/session_012Eacj9naBWSKrevsqnVJWR
Generated by Claude Code