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Equidistribution Theorem

The theorem that successive multiples of an irrational number, reduced modulo one, become uniformly distributed on the unit interval or circle.

Version
v1 · 2026-09-28 · History
Domain-specific #
7636
Domain group
Formal Sciences
Origin domain
Mathematics
Subdomain
Number Theory → Mathematics
Aliases
Irrational-rotation equidistribution theorem

Core Idea

For irrational α, the fractional parts of α, 2α, 3α, … visit every interval of [0,1) with asymptotic frequency equal to that interval's length. Equivalently, repeated rotation of the circle by irrational angle α distributes an orbit uniformly with respect to normalized length. The theorem asserts long-run spatial balance, not random generation or equal spacing at each finite stage. Irrationality is decisive. For rational α, the orbit is periodic and occupies finitely many residues.

Scope of Application

The Equidistribution Theorem is a domain-bounded mathematical result for the deterministic orbit generated by repeated addition of an irrational real number modulo one; an application must preserve that irrational increment, modulo-one circle carrier, and asymptotic uniform-frequency conclusion rather than infer the theorem from a finite even-looking sample. - Uniform distribution modulo one. The fractional-part sequence {nα} for irrational α is the theorem's canonical arithmetic habitat. - Circle rotations. Iterating x ↦ x + α (mod 1) expresses the same result as uniform distribution of an orbit with respect to normalized angle or length measure. - Unit-interval formulations. Identifying the endpoints of [0,1) permits interval occupancies to be compared with interval length under a fixed endpoint convention. - Translated starting points. Orbits of the form x + nα (mod 1) are studied under the same rotation structure, with the starting phase separated from the irrational increment.

Clarity

A clear statement specifies fractional part, modulo-one topology, normalization, test sets, and limiting order. Endpoint conventions do not change interval length but should be consistent. “Eventually covers uniformly” should not be read as a finite stopping guarantee.

Manages Complexity

The Equidistribution Theorem compresses the detailed order of the infinite deterministic orbit \(\{n\alpha\}\) into one limiting occupancy rule. The analyst tracks irrational \(\alpha\), a test interval \(I\), the prefix length \(N\), and the fraction of the first \(N\) residues that fall in \(I\); the theorem replaces all point-by-point positions with the limit \(|I|\). This makes the main regimes immediately readable. The compression stops at asymptotic distribution.

Abstract Reasoning

The circle-rotation representation converts arithmetic fractional parts into a dynamical orbit. Fourier or Weyl-style reasoning tests uniformity through cancellation of nonzero modes. Rational approximation explains both why irrationality prevents closure into a finite orbit and why finite prefixes can still look uneven.

Knowledge Transfer

Within number theory, dynamics, and uniform-distribution theory, the theorem transfers literally between fractional-part and circle-rotation coordinates, to translated starting points where the same invariant measure is preserved, and among equivalent interval-frequency, averaging, or Weyl-criterion formulations. What carries is the irrational rotation x ↦ x + α (mod 1), the empirical frequency of visits to test intervals, and the asymptotic equality with normalized length. Beyond this particular orbit, the honest reach is B — shared abstract mechanism through Equidistributed Sequence, with A — analogy for data that merely look even.

Relationships to Other Abstractions

Local relationship map for Equidistribution TheoremParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.EquidistributionTheoremDOMAINDomain-specific abstraction: Equidistributed sequence — is part ofEquidistributedsequenceDOMAIN

Current abstraction Equidistribution Theorem Domain-specific

Parents (1) — more general patterns this builds on

  • Equidistribution Theorem is part of Equidistributed sequence Domain-specific

    The theorem contains the equidistributed-sequence property as a constitutive part of its conclusion: for irrational α, the carrier {nα} satisfies the all-subinterval limiting-frequency invariant.

Hierarchy path (1) — routes to 1 parentless root

Neighborhood in Abstraction Space

Equidistribution Theorem sits in a sparse region of the domain-specific corpus (75th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Combinatorial Optimization & Discrete Structures (31 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08