Integrated Sachs-Wolfe · ISW
unseel.com · CMB photon crosses a decaying well · ∂Φ/∂t ≠ 0
ΔT/T 0
well depth 100%
phase
CMB photon (cool)
Photon blueshifted (hot)
Gravitational well
Dark energy flattens it
Unseel.com · Integrated Sachs-Wolfe