P1–P10 test the statistical backbone. P11–P13 test topology-linked node environments. Every card states an observable, an expected pattern and an outcome that counts against ICH.
EUCLID OBSERVABLE · Tomographic shear and clustering residuals
Any significant large-scale pattern should keep an approximately stable shape across redshift.
A residual that clearly changes shape or sign with redshift beyond known systematics or astrophysics.
EUCLID OBSERVABLE · Residual-mode amplitude in shear and clustering fits
The imprint remains a sub-percent to percent-level correction, never a dominant component.
A coherent deviation of order 10% required to fit Euclid data.
EUCLID OBSERVABLE · E-mode maps, low-ℓ tests and shear–LSS cross-correlations
A low-ℓ coherent residual survives independent pipelines, masks and systematics treatments.
A mode that vanishes under minimal pipeline changes or exists in only one analysis choice.
EUCLID OBSERVABLE · Euclid overlap with DES, KiDS, HSC, Planck and others
Direction or structure should reproduce across independent surveys within uncertainty.
A strongly Euclid-only or survey-dependent pattern, or one that flips direction in overlaps.
EUCLID OBSERVABLE · BAO distance ladder and geometric clustering probes
Background expansion stays standard within measurement uncertainty.
A robust need for modified expansion as the primary explanation of Euclid data.
EUCLID OBSERVABLE · Stacked void-lensing profiles and void–galaxy correlations
Any deviation is smooth, gentle and coherent across void definitions and redshift bins.
Sharp localized features or strongly redshift-evolving void anomalies.
EUCLID OBSERVABLE · Cluster weak lensing, richness–mass trends and stacks
Only a small, smooth modulation of reconstructed potentials is permitted.
An additional localized mass-like component attributable to the imprint.
EUCLID OBSERVABLE · High-ℓ shear, small-separation galaxy lensing and substructure
The imprint lives at the largest scales, not in sharp or high-frequency structure.
A claimed detection that appears mainly at small scales or requires sharp spatial support.
EUCLID OBSERVABLE · High-z abundance and field-to-field variance
Rare regions may show mildly accelerated growth; the effect must not be sky-wide.
A uniform excess requiring a global growth change or strongly time-evolving imprint physics.
EUCLID OBSERVABLE · Hemispherical asymmetry and preferred-axis searches
Any preferred direction is weak and compatible with existing isotropy constraints.
Strong anisotropy, anisotropic expansion or a signal that grows strongly with cosmic time.
EUCLID OBSERVABLE · Euclid-defined massive nodes × independent extreme-quasar/AGN catalogs
After standard controls, massive nodes retain an enhanced extreme-luminosity or black-hole-mass tail.
No residual node enhancement after controlling for redshift, halo and host mass, density, duty cycle, obscuration and selection.
EUCLID OBSERVABLE · Node topology and inferred mass × luminosity, quiescent nuclei and low-accretion tracers
A population of massive but underluminous node environments remains after standard controls.
Candidates resolve into low-mass true voids, ordinary faint systems or show no node-like topology and no excess faded-remnant channel.
EUCLID OBSERVABLE · Massive nodes and filaments × gas, feedback, SZ, X-ray, radio, H I and WHIM tracers
Node-linked environments retain residual feeding, heating, depletion, expulsion, inflow or redistribution signatures.
No residual topology-linked enhancement after standard density, halo, merger, feedback, gas-physics and selection controls.
Surviving signals must remain part of the same narrow class: weak, smooth, ultra-large-scale, non-localized, non-dynamical and background-preserving. A collection of unrelated anomalies does not support ICH.