birkhoff-average

plurigrid's avatarfrom plurigrid

Time average of observable along trajectory

⭐1stars🔀2forks📁View on GitHub🕐Updated Jan 9, 2026

When & Why to Use This Skill

The Birkhoff Average skill provides advanced computational tools for analyzing dynamical systems by calculating the time average of observables along trajectories. It is essential for researchers and engineers working with differential equations, manifold flows, and complex system modeling to determine long-term qualitative behavior and ergodic properties.

Use Cases

  • Analyzing long-term dynamics and limit sets to understand the global structure of complex physical systems.
  • Investigating system stability and robustness under perturbations within dynamical systems theory.
  • Identifying and studying bifurcations and qualitative changes in systems dependent on specific parameters.
  • Integrating with Julia's AlgebraicDynamics.jl for compositional modeling of resource-sharing machines and categorical dynamics.
namebirkhoff-average
descriptionTime average of observable along trajectory
version1.0.0

Birkhoff Average

Trit: 1 (PLUS) Domain: Dynamical Systems Theory Principle: Time average of observable along trajectory

Overview

Birkhoff Average is a fundamental concept in dynamical systems theory, providing tools for understanding the qualitative behavior of differential equations and flows on manifolds.

Mathematical Definition

BIRKHOFF_AVERAGE: Phase space × Time → Phase space

Key Properties

  1. Local behavior: Analysis near equilibria and invariant sets
  2. Global structure: Long-term dynamics and limit sets
  3. Bifurcations: Parameter-dependent qualitative changes
  4. Stability: Robustness under perturbation

Integration with GF(3)

This skill participates in triadic composition:

  • Trit 1 (PLUS): Sources/generators
  • Conservation: Σ trits ≡ 0 (mod 3) across skill triplets

AlgebraicDynamics.jl Connection

using AlgebraicDynamics

# Birkhoff Average as compositional dynamical system
# Implements oapply for resource-sharing machines
  • equilibrium (trit 0)
  • stability (trit +1)
  • bifurcation (trit +1)
  • attractor (trit +1)
  • lyapunov-function (trit -1)

Skill Name: birkhoff-average Type: Dynamical Systems / Birkhoff Average Trit: 1 (PLUS) GF(3): Conserved in triplet composition

Non-Backtracking Geodesic Qualification

Condition: μ(n) ≠ 0 (Möbius squarefree)

This skill is qualified for non-backtracking geodesic traversal:

  1. Prime Path: No state revisited in skill invocation chain
  2. Möbius Filter: Composite paths (backtracking) cancel via μ-inversion
  3. GF(3) Conservation: Trit sum ≡ 0 (mod 3) across skill triplets
  4. Spectral Gap: Ramanujan bound λ₂ ≤ 2√(k-1) for k-regular expansion
Geodesic Invariant:
  ∀ path P: backtrack(P) = ∅ ⟹ μ(|P|) ≠ 0
  
Möbius Inversion:
  f(n) = Σ_{d|n} g(d) ⟹ g(n) = Σ_{d|n} μ(n/d) f(d)