Projector route
Koide is expressed as equal quadratic weight in democratic and residual projector sectors.
PDF summary and reading guide
A no-trigonometry algebraic comparison separating several routes that all meet at 2/3 when D = 3, using Koide projectors, D = 3 + epsilon deformation, FFGFT inputs, rank splits, and recursive closure.
This page has been rebuilt from the local PDF. The document is about 4,518 extracted words across 16 pages. Its central move is diagnostic: it does not claim that every appearance of 2/3 has one origin. It separates the mechanisms by asking how each one responds to a formal deformation D = 3 + epsilon.
Read this after the recursive closure and Hopfion/topology notes, because it is a discipline page for number coincidences. It teaches the site how to say: "these routes agree at the undeformed point, but their deformation response is different, so they are not automatically the same mechanism."
Best first use. Use the epsilon response as a claim filter. Reproducing 2/3 at D = 3 is not enough; a proposed mechanism should say which derivative or residual it predicts.
The note starts with notation, rewrites Koide as a projector equality, generalises the projector statement to D components, compares three routes to 2/3, computes epsilon expansions, defines a Koide residual diagnostic, evaluates physical charged leptons, checks FFGFT/T0 inputs, and ends with a route table.
Koide is expressed as equal quadratic weight in democratic and residual projector sectors.
Some 2/3 appearances come from a complement law, such as 1 - 1/D at D = 3.
Rank splits such as 16/24 are meaningful only after the space, involution, projectors, ranks, and invariants are specified.
The FFGFT/T0 inputs are treated as a mass-generation route near the Koide surface, not as an exact Koide derivation.
At D = 3, several algebraic paths pass through 2/3. Under D = 3 + epsilon, they usually separate. That separation is not a nuisance; it is the test. The deformation reveals whether the claim is about equal projector weights, a complement-of-step rule, a midpoint, a rank split, an FFGFT exponent ladder, or recursive closure.
At D = 3, many roads meet at 2/3; at D = 3 + epsilon, the roads separate.
These formulas are the live algebraic spine of the page. They are intentionally angle-free.
x_i = sqrt(m_i)
u = (1, 1, 1)^T
Q = (x^T x) / (u^T x)^2
P = u u^T / (u^T u) = u u^T / 3
P_perp = I - P
A = x^T P x, B = x^T P_perp x
Q = (A + B) / (3 A)
Q = 2/3 <=> A = B
P_D = u_D u_D^T / D, P_{D,perp} = I - P_D
Q_D = (A_D + B_D) / (D A_D)
equal-projector route: Q_proj(D) = 2 / D
complement route: p_comp(D) = 1 - 1 / D
midpoint route: Q_mid(D) = (1/2)(1 + 1/D)
Delta_K = 3 Q - 2 = B/A - 1
Delta_K^(D) = D Q_D - 2 = B_D/A_D - 1
recursive closure: S = (1 - r)L + rS
resolved complement: 1 - r
rank split: rank(P_+)/dim(V) = 8/24 = 1/3, rank(P_-)/dim(V) = 16/24 = 2/3
FFGFT generator: m_i = r_i xi^{p_i} v
FFGFT-to-Koide map: (r_i, p_i, xi) -> x_i = sqrt(r_i) xi^{p_i/2} -> (A, B) -> Q
The clean discriminator is the first derivative at the undeformed point. The three simple routes meet at 2/3 when epsilon is zero, but they respond differently as epsilon changes.
Q_proj(3 + epsilon) = 2/(3 + epsilon), with first response -2/9.
p_comp(3 + epsilon) = 1 - 1/(3 + epsilon), with first response +1/9.
Q_mid(3 + epsilon) = (1/2)(1 + 1/(3 + epsilon)), with first response -1/18.
If a model says "2/3" but cannot state its deformation response, the mechanism is still underspecified.
The physical charged-lepton vector is extremely close to equal projector weight but not exactly equal at the central values used in the note. The diagnostic residual is small and is dominated experimentally by the tau mass uncertainty.
physical charged leptons: Q ~= 0.6666644634
physical residual: Delta_K ~= -6.6097565e-6
For the quoted FFGFT/T0 rational inputs, the note obtains a nearby but distinct Koide value. That number is not treated as an exact derivation of Koide. It is a proximity diagnostic for the mass-generator route.
FFGFT quoted input: xi = 4/30000 = 1/7500
FFGFT coefficients: r_e = 4/3, r_mu = 16/5, r_tau = 25/9
FFGFT exponents: p_e = 3/2, p_mu = 1, p_tau = 2/3
Q_FFGFT ~= 0.6677418577
Q_FFGFT - 2/3 ~= 0.0010751910
The document's mature conclusion is that repeated numbers need maps, not excitement. Koide projector equality, FFGFT exponent architecture, rank-split mediation, and recursive closure can all touch 2/3, but each starts from a different primitive object.
The safe reading is: this is a diagnostic note, not a proof that all 2/3 appearances share one source. Its purpose is to prevent number-chaining by demanding the primitive object, map, residual, and deformation response.
Delta_K = 3Q - 2 = B/A - 1, measuring distance from equal projector weight.Read sections 3 through 7 first, because they give the projector algebra and the residual diagnostic. Then read sections 12 through 20 for the FFGFT and cross-framework comparisons. Keep the conclusion in view: reproducing 2/3 is not enough; a mechanism must specify its route.