Prime roots on complete return-chart families
Abstract
Prime cardinality turns component routing into an exact local-or-cyclic root criterion.
Let p be any prime natural number, H any group, X:Fin p->Type an arbitrary dependent family, and A_i:ReturnAtlas H (X i) complete signed return charts. Write d_i>0 for their atlas periods and h_i for their holonomies. DependentReturnAtlases(H,X) denotes precisely this dependent family of charts, and Sigma(X) is the entire disjoint carrier of pairs (i,x) with x:X i. The chart equality is A_i(t,z)=A_i(s,w) exactly when t=s+d_im and zh_i^m=w for some integer m. The group may be infinite and noncommutative. The d_i are primitive-base return periods, not ordinary minimal periods of the lifted time maps.
Definition 1.1 (Time on the dependent union).
Formalization. D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.jointTime (✓ std3).
Source. Repository-derived.
Commentary.
For an arbitrary index type J and a family A_j, the time map T sends (i,x) to (i,A_i.time(x)). Every point of every chart remains in the carrier.
Definition 1.2 (Left deck action on the dependent union).
Formalization. D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.jointDeck (✓ std3).
Source. Repository-derived.
Commentary.
For an arbitrary index type J and a:H the deck map D_a sends (i,x) to (i,A_i.deck(a,x)). It uses the same left group element in each component; signed return holonomy still multiplies on the right.
Definition 1.3 (The full signed local equation).
Formalization. D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.Local (✓ std3).
Source. Repository-derived.
Commentary.
Local p B means that s:Fin B.period, m:Int and b:H satisfy bB.holonomy=B.holonomyb, ps.val=1+B.periodm and b^p*B.holonomy^m=1. The integer m can be negative. This is the existing exact ReturnAtlas.root_criterion equation, with no ordinary-time-period replacement.
Theorem 1.4 (Exact prime-family root criterion).
Proof. Machine-checked in Lean as D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.prime_root_criterion (✓ std3). ∎
Source. Repository-derived.
Commentary.
There exists a map R:Sigma X->Sigma X with R(D_a(q))=D_a(R(q)) for every a and q, and R iterated p times equal to T, if and only if either every A_i satisfies Local p A_i or for every i,j one has d_i=d_j and some b:H with bh_j=h_ib. The two alternatives may overlap. R is not assumed to preserve charts, be bijective, or commute with time.
Necessity first derives time commutation from R^p=T and injectivity from the injectivity of T. Completeness of each chart makes the target component of R(i,x) independent of x: deck moves cover its group coordinate, and nonnegative time moves cover its normalized finite phase. This induces sigma:Fin p->Fin p with sigma^p=id. Each restricted map between routed components is injective and intertwines deck and time. Apply ReturnAtlasFiniteCovers.normal_form and its actual fiberEquiv: a positive degree m gives Fin m equivalent to the full preimage of every target point. Injectivity forces any two such preimages equal; if m>1 the images of 0 and 1 contradict injectivity of that equivalence. Hence m=1, yielding equal atlas periods and bh_j=h_ib without counting H.
If sigma fixes every index, restriction gives an actual pth root in each chart, and the existing local root criterion gives all local equations. Otherwise choose a nonfixed index o. Mathlib’s prime minimal-period theorem gives minimalPeriod(sigma,o)=p. Its p distinct iterates exhaust Fin p. Apply the same injective-factor argument to every iterate of R to identify A_o with every chart. Inverting and composing the resulting conjugacies gives the displayed condition for every ordered pair i,j. No fixed-order enumeration is used.
For sufficiency, local roots combine directly on the dependent union. In the other case choose gauges b_i with b_ih_i=h_ob_i and equal periods. Existing complete-coordinate transport identifies the entire union with Fin p times X_o, by (i,x)->(i,transport(A_i,A_o,b_i inverse,x)). In these coordinates define C(i,y)=((i.val+1) mod p, T_o^floor((i.val+1)/p)(y)). Induction proves C^n(i,y)=((i.val+n) mod p, T_o^floor((i.val+n)/p)(y)). Thus C^p(i,y)=(i,T_o(y)); exactly one time step occurs at the wrap. Deck commutation of T_o makes C deck equivariant. Conjugating C back through the full chart equivalence constructs the required actual map R.
This connects cyclic permutation arithmetic, the signed finite-cover degree, and nonabelian holonomy conjugacy. The restriction to exactly p charts makes a single nonfixed prime orbit fill the entire index set. Larger finite families require additional orbit multiplicity information; no criterion for those families is asserted here. These arguments combine established permutation and return-chart mechanisms, with no claim of literature priority.
References
- Truth anchor:
D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.Local - Truth anchor:
D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.jointDeck - Truth anchor:
D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.jointTime - Truth anchor:
D5/S3/ConceptDynamics/Coding/PrimitiveLifts/PrimeOrbitRootCriterion.prime_root_criterion - Dependency: D5/S3/ConceptDynamics/Coding/PrimitiveLifts/ReturnAtlasFiniteCovers