What this paper does. Establishes a single Layer-1 theorem in the binary icosahedral group: the σ-Galois involution acting on the 120 vertices of V600 = 2I partitions every Dic5-coset into exactly 4 fixed and 16 mobile vertices. The pure ratio 4/16 = 1/4 matches the Bekenstein–Hawking entropy coefficient. The paper is deliberately narrow: a parameter-free finite-group fact, verified by exact-rational arithmetic.
Epistemic status. A theorem-grade arithmetic identity, not a derivation of black-hole entropy. We do not claim that V600 represents physical black holes, that the involution is the unique source of the Bekenstein coefficient, or that any cascade-cosmogenesis machinery follows from this paper. Calibration is open. Ontology is open. The structural ratio is the entire claim.

The Setup

The binary icosahedral group V600 = 2I sits inside the unit quaternions as 120 elements; its image in SO(3) is the icosahedral rotation group of order 60. Inside V600 live two distinguished subgroups used by this paper:

Bulk subgroup

Dic5: order 20

The binary dihedral group of order 20, embedded as a subgroup of V600. It partitions the 120 vertices of V600 into exactly 6 cosets of size 20.

Galois involution

σ on ℤ[φ]

The non-trivial Galois automorphism of ℚ(√5), sending φ = (1+√5)/2 to its conjugate φ̄ = (1−√5)/2. Applied vertex-wise to the coordinates of V600.


The Theorem

The structural claim of the paper takes one sentence to state and one verification certificate to confirm:

|coset ∩ Fix(σ)| = 4  and  |coset \ Fix(σ)| = 16
For every coset of Dic5 in V600 = 2I, the σ-fixed vertices number exactly 4, the σ-mobile vertices number exactly 16. Six cosets, identical incidence pattern.

The proof reduces to a finite enumeration: explicit coset representatives, explicit vertex coordinates in ℤ[φ], and the action of σ computed in exact rational arithmetic. The pattern is rigid — not statistical, not approximate, not generically true and refined to specifics, but identical 4+16 partition in all six cosets.


The Identity

4 / (4 + 16) = 1/5    and    4 / 16 = 1/4
Two ratios fall out of the same incidence theorem. The 4/16 = 1/4 ratio — fixed-to-mobile — is the one that matches the Bekenstein–Hawking entropy coefficient.

Bekenstein and Hawking's celebrated semiclassical result that the entropy of a black hole is one quarter of its horizon area — in natural units — carries a coefficient of 1/4 whose origin has been the subject of decades of debate. This paper records that the same numerical coefficient appears in the σ-Galois incidence pattern of Dic5-cosets in 2I, as a pure finite-group ratio independent of any continuum geometry.


What the Match Is, and Is Not

The paper's interpretive section is restricted in scope. Fixed vertices are interpreted as entropy bits; mobile vertices, as horizon channels. This interpretation is offered as a structural map, not a derivation. The paper does not produce Hawking radiation, dynamical black-hole evaporation, or a continuum-limit area law.

Layer 1

The arithmetic identity

4/16 = 1/4 is theorem-grade. Verified by enumeration in pure Python rationals. Six out of six cosets.

Layer 2

The numerical match

The structural 1/4 coincides with the Bekenstein–Hawking coefficient. Reported as a numerical coincidence between two independently-defined ratios.

Not claimed

Physical derivation

No claim that V600 represents physical black holes, that the match is unique among finite groups, or that ontology has been resolved.


What Is Explicitly Out of Scope

  • All cosmological content — expansion rates, CMB, perturbation theory
  • Hawking-radiation continuum mechanics and full semiclassical recovery
  • Claims about quantum gravity as a complete theory
  • The construction of the τσ involution itself (Paper 3 territory)
  • Cascade-cosmogenesis machinery
  • Ontological claims that V600 represents physical black holes
  • Frame-resolution and unit calibration — explicitly held open

Verification

Reproduction

The verification certificate verify.py enumerates all six cosets of Dic5 in V600, applies σ to each vertex, and counts fixed and mobile vertices in pure Python rational arithmetic. The 4+16 partition is established exactly — no floating-point arithmetic, no approximations.

The shared library vfd_v600 generates V600 from canonical quaternionic generators, constructs Dic5, and provides the σ-action. All test cases pass. The certificate runs in seconds.


Strategic positioning. Paper 1 is the narrowest, hardest-to-dismiss point in the V600 programme: a finite-group ratio that requires no fitting, no continuum approximation, and no interpretive commitments to be a true statement. Whether the structural match to the Bekenstein–Hawking coefficient reflects underlying physics is a separate question — one this paper does not attempt to settle.

One identity. Six cosets. Four fixed, sixteen mobile. The ratio is exact. The interpretation is open.