Γ_R and the Roe-candidate marked quotient (Roe note §1, Definition 1.1 ⟦def:GammaR⟧) #
The Roe-candidate group, defined by the same marked-quotient construction as Γ_A
(GQ2/GammaA.lean, paper §2.1 eq. (7)): let F₄ be the free profinite group on σ, τ, x₀, x₁;
call a finite quotient φ : F₄ ⟶ G R-admissible if the pushed marking generates G,
satisfies the tame relation τ^σ = τ² and the Roe wild relation r_R = 1 (note eq. (1.2)
⟦eq:relators⟧, verbatim \rR=(x_0^\sigma)^{-1}a\,x_1^2c), and the normal closure of the images of
x₀, x₁ is a 2-group; then
N_R = ⋂ {ker φ | φ R-admissible}, Γ_R = F₄ ⧸ N_R.
Only the wild relation differs from Γ_A: the tame relation, the pro-2 condition, and the whole
marked-quotient scaffolding (univMarking, Marking.toHom, surjective_of_map_generates) are
reused verbatim from GQ2/GammaA.lean.
This file provides the Roe relation r_R in its profinite reading: the note's auxiliary words
of eq. (1.1) ⟦eq:defwords⟧ with genuine ω₂ ∈ ℤ̂ exponents (Marking.aRHat, Marking.y1RHat,
Marking.cRHat, Marking.wildRelatorR, via ^ᶻ omega2 from GQ2/Zhat.lean; the σ₂ = σ^{ω₂}
letter reuses the shared Marking.sigma2Hat of Γ_A). The fidelity bridge
Marking.map_wildRelatorR / Marking.map_wildRelatorR_eq_one_iff proves that pushing the
profinite word wildRelatorR through a finite quotient computes exactly Marking.wildValueR of
GQ2/Roe/Words.lean — so killing the profinite relator is the same condition as the finite Roe
wild relation WildRelR, and the R-admissibility used in N_R is exactly the note's.
Alongside Γ_R this file supplies Marking.map_admissibleR (R-admissibility pushes forward
along surjective quotient maps — the Roe counterpart of Marking.map_admissible,
GQ2/Subdirect.lean) and the certificate NR_le_ker (every R-admissible continuous hom to a
finite group has N_R in its kernel). The limit facts about Γ_R itself (relators die,
admissible-opens characterization, pro-2 wild core) are GQ2/Roe/AdmissibleLimit.lean.
The Roe auxiliary words with genuine profinite ω₂-exponents (note eq. (1.1)) #
a = (x₀⁻³ τ)^{ω₂} (note eq. (1.1) ⟦eq:defwords⟧, verbatim a=(x_0^{-3}\tau)^{\omegaTwo}),
profinite reading with the genuine profinite exponent ω₂ ∈ ℤ̂. The finite counterpart is
Marking.aR (GQ2/Roe/Words.lean).
Equations
- t.aRHat = GQ2.zpowHat ((t.x₀ ^ 3)⁻¹ * t.τ) GQ2.omega2
Instances For
y₁ = x₁^{σ₂} (note eq. (1.1) ⟦eq:defwords⟧, verbatim y_1=x_1^{\sigma_2}), profinite
reading, reusing the shared σ₂ = σ^{ω₂} = Marking.sigma2Hat of Γ_A. Finite counterpart
Marking.y1R.
Instances For
c = [x₁, y₁] (note eq. (1.1) ⟦eq:defwords⟧, verbatim c=[x_1,y_1]), profinite reading.
Finite counterpart Marking.cR.
Instances For
The Roe wild relator word r_R = (x₀^σ)⁻¹ · a · x₁² · c (note eq. (1.2) ⟦eq:relators⟧,
verbatim \rR=(x_0^\sigma)^{-1}a\,x_1^2c), in the profinite reading — its ω₂-letters (inside
aRHat and inside cRHat's sigma2Hat) use the genuine profinite exponents above. The Γ_A
analogue is Marking.wildRelator; the finite value is Marking.wildValueR
(GQ2/Roe/Words.lean).
Instances For
Faithfulness bridge: the profinite Roe word evaluates to the finite Roe word #
Through any continuous homomorphism to a finite group, the ^ᶻ omega2-ledger of wildRelatorR
computes the powOmega2-ledger wildValueR of GQ2/Roe/Words.lean — via the profinite-
exponentiation headline map_zpowHat_omega2, pushed through the three Roe letters. In particular
the Roe relation read profinitely (relator dies) and finitely (WildRelR of the pushed marking)
are the same condition (map_wildRelatorR_eq_one_iff) — the fidelity-critical lemma, exactly
mirroring GQ2.Marking.map_wildRelator_eq_one_iff.
Word-for-word fidelity: the profinite Roe wild relator evaluates, through any finite
quotient, to the finite Roe wild relator value Marking.wildValueR of the pushed marking — the
content underlying map_wildRelatorR_eq_one_iff. (The Γ_A monolithic analogue is folded into
GQ2.Marking.map_wildRelator_eq_one_iff; here it is exposed separately as a stress test.)
Roe relation r_R, profinite = finite: the Roe wild relator word dies in a finite
quotient iff the pushed marking satisfies the Roe wild relation WildRelR of
GQ2/Roe/Words.lean. Direct analogue of GQ2.Marking.map_wildRelator_eq_one_iff.
R-admissibility pushes forward (Roe counterpart of Marking.map_admissible) #
R-admissibility pushes forward along surjective quotient maps (Roe counterpart of
GQ2.Marking.map_admissible, paper §2 Lemmas 2.1–2.2). If t is an R-admissible marking of a
finite group G and f : G ↠ H is a surjective homomorphism of finite groups, then t.map f is
R-admissible. Only the wild clause differs from map_admissible: map_wildRelR (of
GQ2/Roe/Words.lean) replaces map_wildRel; generation, the tame relation and the 2-core clause
are word-independent (R1 report).
N_R and Γ_R (Roe note Definition 1.1 ⟦def:GammaR⟧; same shape as paper §2.1 eq. (7)) #
An open normal subgroup U ≤ F₄ is R-admissible (note Definition 1.1 ⟦def:GammaR⟧) if
the canonical finite quotient F₄ ⧸ U carries an R-admissible pushed marking: the images of
σ, τ, x₀, x₁ generate, satisfy the tame relation and the Roe wild relation — equivalently (by
map_tameRelator_eq_one_iff / map_wildRelatorR_eq_one_iff) the profinite relator words die —
and the normal closure of the images of x₀, x₁ is a 2-group. Roe counterpart of
GQ2.IsAdmissibleU.
Equations
- GQ2.IsAdmissibleUR U = (GQ2.Marking.map (QuotientGroup.mk' ↑U.toOpenSubgroup) GQ2.univMarking).AdmissibleR
Instances For
N_R (note Definition 1.1 ⟦def:GammaR⟧): the intersection of the kernels of all
R-admissible finite quotients of F₄, encoded as the intersection of all R-admissible open
normal subgroups. Roe counterpart of GQ2.NA.
Equations
- GQ2.NR = ⨅ (U : { U : OpenNormalSubgroup ↑(GQ2.FreeProfiniteGroup (Fin 4)).toProfinite.toTop // GQ2.IsAdmissibleUR U }), ↑(↑U).toOpenSubgroup
Instances For
Γ_R (note Definition 1.1 ⟦def:GammaR⟧): the marked quotient F₄ ⧸ N_R — the largest
quotient of F₄ all of whose finite quotients are R-admissible, constructed exactly as Γ_A
but with the Roe wild relation. Roe counterpart of GQ2.GammaA.
Equations
Instances For
N_R is the note's intersection (Definition 1.1 ⟦def:GammaR⟧): the kernel of every
R-admissible continuous hom to a finite (discrete) group — not just the canonical quotients
F₄ ⧸ U — contains N_R. (The pushed marking being R-admissible forces f surjective, and
R-admissibility transfers to the canonical quotient by the induced isomorphism
F₄ ⧸ ker f ≃* P.) Roe counterpart of GQ2.NA_le_ker.
Paper-tag ledger (Roe note paper/roe-presentation-verification.tex; hand-maintained) #
- eq. (1.1) = ⟦eq:defwords⟧
- eq. (1.2) = ⟦eq:relators⟧
- Definition 1.1 = ⟦def:GammaR⟧