|
Dedekind 0.0.0
A structuralist C++23 Module Library
|
A SYMBOLIC N-th root of unity \(\zeta_N^{\,p}\), carried by its exponent p ∈ ℤ/N (Modular<N>). The unit harmonics \(\mu_N=\{z:z^N=1\}\): the torsion subgroup of the unit circle U(1), cut out of ℂ, cyclic of order N and \(\cong\mathbb{Z}/N\) via de Moivre.
More...
Public Member Functions | |
| constexpr UnitRoot | inverse () const |
| The inverse \(\zeta^{-p}\) (= conjugate, on the unit circle). | |
| constexpr Complex< QuadraticReal< 2 > > | resolve () const |
Collapse to the exact ℂ(ℚ(√2)) value via de Moivre — only N=8, where \(\zeta_8\in\mathbb{Q}(\sqrt2)\); off that base this member is unavailable (a compile-time Honest Rejection). | |
Public Attributes | |
| dedekind::morphologies::Modular< N > | exponent {} |
Friends | |
| constexpr bool | operator== (const UnitRoot &, const UnitRoot &)=default |
| constexpr UnitRoot | operator* (const UnitRoot &a, const UnitRoot &b) |
| The μ_N group law: harmonic product = exponent sum (de Moivre). | |
A SYMBOLIC N-th root of unity \(\zeta_N^{\,p}\), carried by its exponent p ∈ ℤ/N (Modular<N>). The unit harmonics \(\mu_N=\{z:z^N=1\}\): the torsion subgroup of the unit circle U(1), cut out of ℂ, cyclic of order N and \(\cong\mathbb{Z}/N\) via de Moivre.
Arithmetic is multiplicative and symbolic — \(\zeta^p \cdot
\zeta^q = \zeta^{p+q}\), exponent addition in ℤ/N, never a numeric ℂ product. A group, NOT a ring: a sum of harmonics generally leaves \(\mu_N\) (that sum is the ℂ-linear span — the function-space semimodule — not the harmonics). Collapse to an exact ℂ value is deferred to resolve() and exact only where \(\zeta_N\) lives in the base field: N=8 ⊂ ℚ(√2), via root8. Other N would need the cyclotomic field \(\mathbb{Q}(\zeta_N)\) and get no numeric collapse here (a compile-time Honest Rejection).