Research Notes
Routing Costs for Distributed Inverse QFT Architectures
A two-note architecture thread extending the distributed inverse QFT result of Cardama et al. The first note argues that, once phase-angle pruning fixes which inter-QPU communications survive, the physical interconnect determines how far each surviving message must travel: placing logical blocks on a hypercube by Gray code yields a worst-case communication distance of min{D, log2 P} for retained horizon-D interactions. The companion note adds a spectral layer, tying distributed iQFT routing to Path-Length Distributions, Inverse Geometry, and Designed Neighborhood Spectra : iQFT phase decay induces a logical metric, hardware placement turns retained interactions into a phase-weighted routing spectrum, and QPU architecture design becomes an inverse path-volume problem.
- Routing note. HTML writeup or PDF .
- Phase-weighted path-volume extension. HTML writeup or PDF ; connects to Path-Length Distributions .
A Geodesic Event-Study Formalism for Deep-Ocean DART Response After Large Earthquakes
This paper builds a station-normalized event study for DART® deep-ocean bottom-pressure records after large earthquakes, with great-circle distance setting each station's arrival cone and matched random windows from the same station history supplying the null. The mathematical core is a magnitude-geodesic cone-collapse theorem: under damped linear shallow-water propagation on the sphere, the leading response collapses to a common arrival-time shape once scaled by magnitude, damping, and spherical spreading. Empirically, on a 45-day USGS/NDBC live feed, standard meteorological buoys show no wave-height response, while DART® water-column histories light up after large quakes. For M7+ events the scaled cone response is 0.766 against a matched-null mean of 0.394 (p = 0.008, 500 randomizations).
Path-Length Distributions, Inverse Geometry, and Designed Neighborhood Spectra
This note studies geometry through path-volume spectra: instead of tracking only shortest-path distance, it measures how the available volume of one-waypoint detours accumulates by path length. The result is an inverse problem for reconstructing metric-measure geometry from local path spectra, with shifted lognormal laws serving as a model for multiplicative detour structure.
The PDF paper develops the path-volume geometry, while the companion lognormal spectrum optimization demo realizes the finite-sample design objective by evolving points in R2 so anchor-wise neighborhood distance spectra match a target shifted lognormal.
Algorithms as Geodesics: Flattening Entropy and Partial Curvature Removal in Sorting
This paper reframes algorithms as geodesics in a geometry defined by admissible primitive operations, where classical complexity lower bounds become curvature obstructions — statements that no global flattening coordinate chart exists inside the model. Counting sort is shown to be a literal flattening theorem: in histogram coordinates the relevant state space is globally flat, its Levi-Civita connection and Riemann tensor vanish, and the essential computation is geodesic transport to the endpoint histogram. Comparison sorting saturates a matching quantitative obstruction called the flattening entropy, ℱcmp(n) = log(n!) + O(1), and every ordered bucketization removes an explicit multinomial block of sorting curvature, leaving a residual problem whose size is a precise entropy. Radix sorting is recovered as iteration of this principle, continuously interpolating between pure comparison and full geometric flattening.
- Main note. Algorithms as Geodesics - develops flattening entropy, counting sort as global flattening, and ordered bucketization as partial curvature removal.
- Emergent obstruction. Flattening Entropy from Comparison Geometry - realizes comparison lower bounds as path-length statements on the simplex of order-type uncertainty.
- Learned partial flattening. Learned Monotone Bucketization as Partial Flattening - learns a monotone preprocessing chart whose balanced buckets remove sorting entropy before exact local refinement.
This extends the geometric sorting framework in my arXiv paper .
Angle-Distribution Relaxation in a Many-Body Orbital System
This note studies how orbital-plane inclinations evolve in a many-body system with a dominant central mass. It separates the exact Newtonian dynamics from a coarse-grained relaxation model: after averaging over fast orbital phases and weak interactions, the preferred plane orthogonal to the total angular-momentum axis acquires a quadratic energy penalty for small inclination, producing an effective restoring drift.
Under an overdamped stochastic closure, the induced Fokker-Planck equation becomes an Ornstein-Uhlenbeck model with a stationary Gaussian angle law and explicit exponential convergence in relative entropy and total variation. The stylized HTML writeup is tuned for mobile reading, while the PDF writeup presents the same result in a more formal paper style.
A companion initial exploration, Orbital Plane Stability and Geometric Robustness Under Perturbations , isolates the two-body case: conservation of angular momentum fixes the orbital plane, while external forcing changes orientation through torque and affects escape through a separate energy channel.
Gaussian Halfspace Testing, Distributional Robustness, and the Lognormal Pullback
This note begins with Chen, De, Huang, Nadimpalli, Servedio, and Yang’s Sublinear-query relative-error testing of halfspaces , which shows that Gaussian geometry makes relative-error halfspace testing sublinear in dimension. It then extends that setting in three directions: a total-variation robustness theorem for transporting Gaussian testers through coordinate changes, an exact lognormal pullback where the problem becomes an ordinary halfspace test in log coordinates, and an explicit multivariate-t perturbation bound together with a sketch toward stability of query complexity itself.
Preprint: preprint PDF . The earlier draft PDF is still available as a less polished working version with a bit more speculation.
Noether, Energy-Conserving Transitions, and Distributed Repair
This cluster develops energy conservation as geometry: first as a Noether-style admissibility filter on possible futures, then as a repair-and-redistribution mechanism on a thickened energy shell. Together, the note, paper, and companion animation move from discrete constraint counting to a visual picture of how excess energy is corrected and spread across the system.
- Conservation as filtration. Noether, Energy-Conserving Transitions, and Distance-to-Conservation - formalizes conservation laws as a dimensional reduction on candidate next states and introduces an explicit distance-to-conservation correction metric.
- Distributed repair. Distributed Energy Borrowing - treats off-shell mismatch as excess that can be repaired by minimal coordinated adjustment across degrees of freedom on an admissible energy band.
- Companion visualization. Distributed Energy Borrowing - Shell Ripples Animation - visualizes normal-to-shell repair together with ripple-like redistribution along the conserving shell.
Dynamics and Long-Horizon Stability
This four-note arc explains why models that look stable over short windows can fail under deployment-time drift at long horizons. It connects geometric error decomposition and directional compounding sensitivity to a practical robustness strategy: constrain tangent response specifically along empirically observed drift directions. To formalize this progression, the notes develop a sequence of theoretical results on horizon-scaled error bounds, directional sensitivity of long-run functionals, and variance control through drift-aligned tangent geometry.
- Horizon geometry. Fan-of-Rays Geometry: Bounding Long-Horizon Prediction Error - decomposes terminal miss into initial offset, angle mismatch, and curvature mismatch with explicit horizon scaling.
- Functional sensitivity. Long-Horizon Sensitivity of CAGR Under Infinitesimal Model Perturbations - converts geometric amplification into a concrete compounding metric and shows directional concentration along realized displacement.
- Risk over time. Dynamics Shift and Geometric Robustness in Classification - moves from endpoint error to deployment-time risk volatility, controlled by drift speed and network tangent gain.
- Capstone regularization. Drift-Tangent Regularization - turns the mechanism into a training and monitoring recipe by penalizing directional Jacobian gain along estimated drift subspaces.
- Capstone preprint. Jacobian-Velocity Bounds for Deployment Risk Under Covariate Drift - this manuscript is the capstone project preprint. It formalizes long-horizon deployment instability for frozen predictors under covariate drift, proves volatility control through Jacobian-velocity interaction, introduces drift-aligned tangent regularization, and validates the mechanism on synthetic and real Air Quality experiments.
Density-Based Clustering: A Geometry of Scale
In clustering, turning the density dial reveals a hidden continuous geometry underneath the discrete labels. A short arc: operational event discovery → DBSCAN knob dynamics → a continuous scale surrogate → level-set erosion calculus → equivalence with centroid-based clustering.
- Grounding. Spatiotemporal Event Detection in Structured Grid Data — comments over incidents; delayed timestamps; clustering as inference.
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Discrete behavior.
- Differential Effects of the Minimum Point Threshold on Topology and Motion in DBSCAN — matching splits motion (peeling) from birth/death events.
- A Continuous Sensitivity Theory for Density-Based Clustering Scale — smooth “effective cluster count” via diffusion; sensitivity scales like ε−2.
- Continuous geometry. Density-Level Clustering: Erosion, Centers, and Separation Across a Continuous Threshold — derivative laws for mass/centroid motion under density-threshold erosion.
- Unification. Blob Topology Equals Centroids — after whitening + separation, DBSCAN components coincide with the k-means minimizer.
Creativity and Sorting: Rarity at the n log n Boundary
A concrete “creativity = rare compression” story for comparison sorting. It proves a boundary/rarity theorem for decision trees under an uninformed prior, lifts the same idea to the permutohedron where efficient sorts correspond to geodesic-like paths, and connects the discrete picture to the continuous contraction view of sorting as gradient flow.
This connects to the gradient-flow formulation in:
my arXiv paper
.
Geodesics on the Permutohedron
A derivation bounding the number of shortest paths between permutations in the
permutohedron in terms of Kendall distance. The result makes the exponential
branching structure of permutation space explicit.
This complements the geometric sorting framework in:
my arXiv paper
.
Permutohedron Geometry & Distance Comparisons
A short note analyzing three natural metrics on the permutohedron: the graph distance,
geometric edge distance, and direct Euclidean distance. The construction gives clean comparison
theorems showing how inversion count controls edge-based paths, and why straight-line Euclidean
distance is always strictly smaller than any route restricted to edges. This clarifies how
discrete order geometry interacts with embedded Euclidean structure.
This relates to the geometric sorting formulation in:
my arXiv paper
.
Opposite-Skewness Symmetry & TV Bounds
A short, self-contained note showing how two scaled Beta distributions can share the same
support, mean, and median while exhibiting opposite skewness via centered reflection.
It gives a clean total-variation expression in terms of the density’s overlap with its mirror and a
small-imbalance approximation that links TV directly to parameter differences. In ticket-pricing
applications, this symmetry reflects opposite-skew pricing distributions for the same
event snapshot, highlighting why full-shape geometry (not just mean/variance) matters for model
robustness and divergence-based evaluation.
For related work and broader context, see
my arXiv paper
.
Neural Net Dropout Viewed as Probability-Mass Dilution
This short note extends the implicit regularization mechanism proved in my Random Forests work to neural networks. By viewing dropout as random thinning of active units, it derives a concise odds-compression inequality showing how dropout reduces dominance of high-scoring units. The note directly connects to Section 5 of my arXiv paper .
Limits of Hawking-Induced Magnetism
This series of short notes explores the boundary between quantum evaporation effects and classical plasma dynamics around Kerr black holes. Each note tackles a different facet of why Hawking-induced magnetic fields remain negligible and structurally undetectable compared to accretion-disk–driven fields.
- Magnetic Fields from Hawking Radiation vs. Accretion Disk Dynamics – Scaling arguments show Hawking-radiated charges cannot compete with disk dynamo fields across astrophysical regimes.
- Unphysical Magnetic Field Parity – Proves impossibility in two directions: capped growth forbids parity in forward models, and inverse decompositions cannot recover Hawking modes.
- Non-Identifiability of Subcomponents – A general theorem on information loss in aggregates, applied to Hawking fields, showing zero channel capacity for detection.