Graph-Coherence Toy Theory

A small research page for a graph-coherence toy model

A compact micro-preprint for the frozen linear baseline, the nonlinear weak-link extension, and the public artifacts that support the current numerical claims.

What the current prototype does and does not claim

The frozen baseline reproduces known fixed-Hamiltonian linear quantum behavior on graphs and should be read as a reformulation, not as new physics. The first candidate novelty appears only after adding state-dependent weak-link backreaction. In that nonlinear layer the scan shows memory, hysteresis, and incomplete-transfer regimes relative to the fixed-Hamiltonian baseline.

What is not new yet and what may be new

The page is organized as a control-versus-extension comparison: a frozen linear baseline, then a separate nonlinear layer where the first candidate deviation is explicitly introduced and scanned.

Not new yet

  • Interference on a graph.
  • Partial which-path visibility loss.
  • Quantum eraser behavior.
  • Clustered linear modes.
  • Effective geometry from connectivity.
  • Fixed-Hamiltonian linear graph-QM reformulation.

Candidate novelty

  • State-dependent weak-link dynamics.
  • Occupation-dependent spectral splitting.
  • Finite-relaxation memory effects.
  • Hysteresis measured by loop area.
  • Incomplete-transfer regimes.
  • Nonlinear deviation relative to the fixed-Hamiltonian baseline.

Linear baseline

P(Δφ, μ) = 1/2 (1 + μ cos Δφ)

Cluster splitting

Efull = Ecluster ± ε

Backreaction law

εeff(ψ) = ε₀ [1 + α (|ψi|² + |ψj|²)/2]

Baseline v0.1 as the control group

The baseline is frozen and kept separate from the nonlinear claim. The figures below are the control set: linear fixed-Hamiltonian graph dynamics, generated from the Python scripts and kept unchanged while the nonlinear layer evolves independently.

Nonlinear regime map

The nonlinear layer uses a state-dependent weak-link law with finite relaxation, scanned over 300 parameter combinations. The observables reported here are linear and nonlinear swap time, minimum left-cluster weight, maximum link lag, loop area, and norm drift; the main qualitative result is that only a subset of runs enters a memory-bearing incomplete-transfer regime.

Nonlinear law

dε/dt = γ (ε_target(ψ) - ε)

Scan grid

4 states × 5 α × 5 γ × 3 ε₀ = 300 runs

Measured observables

t* , min W_L, max lag, loop area, norm drift

Main nonlinear figure

The loop-area heatmap is promoted to the main figure because it separates pure renormalization from memory-bearing trajectories more cleanly than a swap-time comparison alone.

Representative regimes

Baseline-equivalent

The nonlinear module reduces to the linear baseline within numerical precision: loop area vanishes, link lag vanishes, and the transfer curve is unchanged.

Representative parameters: state = pattern1, ε₀ = 0.1, α = 0.0, γ = 0.5

Pure nonlinear renormalization

The transfer time shifts strongly, but the trajectory still behaves as if the weak links were replaced by a different static value rather than by a memory law.

Representative parameters: state = pattern2, ε₀ = 0.2, α = 12.0, γ = 0.5

Memory regime

Link relaxation and occupation feedback stop the system from reaching full transfer, and the trajectory traces a visible hysteresis loop.

Representative parameters: state = node0, ε₀ = 0.3, α = 12.0, γ = 4.0

Quantitative verdict

60

Baseline-equivalent runs

164

Pure nonlinear renormalization runs

76

Memory plus incomplete-transfer runs

Strongest loop-area case

state = node0, ε₀ = 0.3, α = 12.0, γ = 4.0

loop area = 0.2619, max link lag = 0.4330

Strongest tunneling-suppression case

state = node0, ε₀ = 0.3, α = 12.0, γ = 2.0

min W_L = 0.1894, loop area = 0.1711

Canonical public artifacts

These files are the canonical public source of truth for the current nonlinear scan, including the markdown report, the full CSV, the rendered summary, the heatmaps, and the representative trajectories.

Results version 20260414-1 | public site build 2026-04-13

Rendered summary

Loading nonlinear results summary...

Closest known model classes

  • Linear quantum walks and tight-binding dynamics on graphs.
  • Finite-dimensional Hermitian graph models.
  • Nonlinear state-dependent hopping or correlated-hopping classes.
  • Open question: does the present backreaction law define a genuinely distinct regime, or is it reducible to an already known nonlinear class?

Current limits of the evidence

  • The frozen baseline is not new physics; it is a graph-language restatement of linear fixed-Hamiltonian quantum dynamics.
  • Any novelty in the current page comes only from the explicitly added weak-link backreaction law.
  • The current evidence is numerical and still at the toy-model level.
  • The next scientific step is a direct comparison against known nonlinear lattice and graph models.

Live plots in real time

4-Node Graph

Interference and which-path marking

Quantum Eraser

Total counts and post-selected channels

6-Node Clustered Graph

Spectrum, exact modes, and packet timescales

Emergent Geometry

Effective distances and embedding

State-Dependent Weak Links

Nonlinear extension as a separate module

This panel compares the fixed-Hamiltonian baseline and backreacted weak-link dynamics. For a pure cluster pattern the effect nearly collapses to a renormalization, while a node-localized state already produces genuinely new trajectories.