Open_Research

Open Research

What is genuinely open, honestly bounded. The solved problems moved to Detection Capabilities; this page is the frontier.

Resolved (context, briefly)

The method-choice question is closed. Passive statistics (FFT, mutual information, transfer entropy, Granger, CCM) failed on this problem class for a structural reason: the receiver's own exploration noise sits ~500× above any coupling signal in passive data. The shipped answer is the impulse protocol — deliberate, guarded pushes with the receiver holding still, detected by CFAR — validated across coupling shapes including deeply nonlinear cascaded channels and slow drift, zero false positives on controls, with a published boundary map. Passive methods remain interesting only as accelerators (ranking candidates for probe prioritization at scale).

Composition is closed to a measured horizon. Nonlinear composition — curves chained through nonlinear switching elements and summed at converging junctions — predicts far-end response within error bars propagated from each piece: 95 of 97 referee points across four chain seeds, a junction, and a live threshold relay, with the propagated bars validated as honest metrology. The bench capability that did not exist (nonlinearity in the edge itself) shipped with the campaign. Published as From Curves to Cascades.

Beyond the Composition Horizon

Roughly two nonlinear hops at noise σ=0.02: beyond that the far end falls below the detection floor, and composing the measured pieces is the only remaining door. Extending the horizon — a quieter instrument, evidence stacked across probes — is open.

Direct vs Transitive Edges

Distinguishing a direct edge from a two-hop path through an intermediate — the diamond topology is the test cell — remains open. Pairwise curves constrain the answer; they do not yet separate it.

Fast Non-Stationarity

Drift slower than the detection window is handled (local reference windows, drift flags on re-measurement disagreement). Phase transitions faster than the window — a system that changes regime mid-probe — remain open. Candidate directions: shorter adaptive blocks, dwell-based protocols, drift-rate estimation as a first-class measurement.

Scaling the Scan

2-6 agents validated. The O(N²) pairwise scan, turn-taking serialization, and scan-rate vs drift-rate at N >> 6 are open — partly engineering (parallel probe groups, spatial locality), partly fundamental (observability limits under drift). Group-scoped coordination and per-receiver curves (one sender walk measures all listeners) already removed one factor of N.

Prediction-Driven Rescan (the maintenance loop)

A frozen measured map enables prediction: "if node A moves to X, node D responds by Y." When prediction fails, the map is stale — and the error localizes WHERE structure changed. Rescan the neighborhood, diff against the frozen map. The prediction error is the compass: it points toward ignorance; probe where it's most wrong. Designed, prototyped in analysis, not yet an engine loop.

Multi-Cadence Coupling Spectroscopy

The coupling structure revealed at one probe cadence is one view: slow probes see steady-state thermal coupling, fast probes see electrical/capacitive coupling. Different cadences excite different mechanisms; each yields a different graph. When one cadence suffices (dominant mechanism) the single map is honest; multiple concurrent mechanisms need multi-cadence probing, and detecting that need — via prediction error — is itself open.

Meta-Optimization of Sensing

The protocol's own parameters (probe amplitude, block lengths, walk depth, convergence threshold) are tunable against measurement outcomes. The system optimizing its own sensing strategy — choosing experiments by expected information — is a natural, unsolved layer. The current walk is deliberately deterministic; adaptive experiment selection is a rung above it.

From Detection to Steering

The measured map's consumer loop — agents adapting to known coupling, coordinated moves toward chosen targets — is the project's direction and not yet built. With composition closed to its measured horizon (above), the open problems in order are joint action under coupling, then destination-directed steering through the measured map. Each rung gates the next; none is assumed.