Reciprocal Cosmology I: Late-time Ultralight Axion Dynamics as a Unified Explanation for Large-scale CMB Anomalies

This paper proposes that the dynamical thawing of an ultralight axion field
ϕ(x, t) in the late universe can explain multiple large-scale CMB anomalies—low-ℓ
power suppression, hemispherical asymmetry, and TB/EB cross-spectra—from a
single origin. Long-wavelength modes of post-inflationary relic axions and horizonscale
local energy concentration structures (eDAS; excess Directional Asymmetric
Structure, also referred to as pseudo-topological energy-dense asymmetric structures)
are amplified as Hubble damping weakens, inducing late ISW contributions
and direction-dependent cosmic birefringence. The photon-axion coupling gϕγ generates
a spatially anisotropic polarization rotation β(ˆn), producing TB and EB
cross-spectra.v3.1 Final refinements: (1) Complete mathematical definition of
eDAS with all variables explicitly explained; (2) Enhanced figure captions with detailed
physical interpretation; (3) Added timescale context to Table 1; (4) Acknowledgments
include AI collaboration; (5) Final formatting optimized for arXiv submission.
Keywords: CMB anomalies, ultralight axion, cosmic birefringence, ISW
effect, eDAS, parametric resonance, TB/EB cross-spectra, LiteBIRD