Symmetry without a manifold: intrinsic dimension on orbits

📅 2026-09-15
📈 Citations: 0
Influential: 0
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🤖 AI Summary
研究解决了标准维度估计器在有限群等距作用轨道上失效的问题,提出用指数函数替代幂律来描述隐藏宽度与分辨率的关系。
📝 Abstract
The standard geometric derivation of neural scaling exponents takes the intrinsic dimension of a data manifold as its input. On modular addition in $\mathbb{Z}_p$ that derivation has no input. The exact algebraic solution is an orbit of $\mathbb{Z}_p$ acting by isometries. Transitivity alone makes the ratio statistic underlying the standard dimension estimator a point mass, so the estimator is undefined, and here the two nearest neighbour distances coincide exactly. Breaking the symmetry at scale $ε$ returns a number, but one that tracks $1/ε$ with no scale free plateau. We show that the failure is general, since on any finite orbit of a group acting by isometries the estimator reports the resolution at which the set is probed rather than a dimension. What replaces the power law is exponential in hidden width, $L(h)=L_\infty+A\exp(-c\,h^α)$, with $R^2$ between 0.982 and 0.995 against 0.857 to 0.906 for a power law admitting the same floor and fitted under the same protocol. Where the data supply is sufficient the rate belongs to the regulariser rather than to the group, since weight decay moves $c$ by a factor of 47 while group order moves it by 1.10, a residual below seed to seed resolution, for every fixed $α$ between 0.75 and 2. The critical width falls with group order rather than rising, against capacity counting that assigns a fixed number of neurons to each irreducible representation.
Problem

Research questions and friction points this paper is trying to address.

intrinsic dimension
orbit
isometries
neural scaling exponents
resolution
Innovation

Methods, ideas, or system contributions that make the work stand out.

intrinsic dimension
symmetry breaking
exponential function
isometries
neural scaling
C
Chon-Fai Kam
Dipartimento di Fisica e Chimica, Universit`a degli Studi di Palermo, via Archirafi 36, I-90123 Palermo, Italy; Universit´e Paris Cit´e and Universit´e de La R´eunion, BIGR, INSERM UMR S1134, F-75014 Paris, France
M
Miloud Bessafi
EnergyLab, Universit´e de La R´eunion, F-97715 Saint-Denis, France
F
Frédéric Cadet
Universit´e Paris Cit´e and Universit´e de La R´eunion, BIGR, INSERM UMR S1134, F-75014 Paris, France; PEACCEL, AI for Biologics, F-75013 Paris, France