arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2602.16094quant-ph
收藏

李代数分析生成器:近似误差界与 barren-plateau 启发法

Lie-Algebraic Analysis of Generators: Approximation-Error Bounds and Barren-Plateau Heuristics

Toyota Central R & D Labs., Inc.(丰田中央研究开发研究所)

Hiroshi Ohno

AI总结:

本文通过李代数分析生成器,研究量子电路近似误差界与barren-plateau启发法,提出有效频率集扩展规则及基于生成器迹的启发式度量。

摘要:

李代数为量子机器学习中的理论分析提供了一个有用的框架,特别是在混合量子-经典学习中。从函数逼近的角度来看,参数化量子电路的期望值可以被视为三角多项式,其可访问的傅里叶模式由生成器的谱决定。在本研究中,我们描述了:(1)当电路的有效频率集包含在半径为K的球体内的时候,Sobolev球上的L²近似误差的最小最大下界,其形式为Ω(K^{d/2 - r}),对于r > d/2(假设目标函数属于Sobolev空间W_2^r(T^d)),我们还推导了在目标函数Sobolev正则性下的量子电路近似误差的Jackson型上界,以有效带宽的形式表示,该带宽由生成器谱间隙确定;(2)一种由非交换生成器扩大有效频率集所启发的生成器选择规则;(3)基于生成器迹分量的简单启发式度量,旨在表征与barren plateaus相关的训练行为。在玩具问题上的模拟实验展示了频率谱视角和所提出启发法的实用意义。

英文摘要:

Lie algebras provide a useful framework for theoretical analysis in quantum machine learning, particularly in hybrid quantum-classical learning. From the viewpoint of function approximation, expectation values of parameterized quantum circuits can be viewed as trigonometric polynomials whose accessible Fourier modes are determined by the spectra of the generators. In this study, we describe: (1) a minimax lower bound on the $ L^{2} $-approximation error over a Sobolev ball when the circuit's effective frequency set is contained in a radius-$K$ ball, which yields a scaling law of the form $ Ω(K^{\frac{d}{2} - r}) $ for $ r > \frac{d}{2} $ (assuming the target function belongs to the Sobolev space $ W_2^{r}(\mathbb{T}^{d}) $), and we also derive a Jackson-type upper bound on the approximation error of quantum circuits under Sobolev regularity of the target function, expressed in terms of an effective bandwidth determined by generator spectral gaps; (2) a generator-selection rule motivated by enlarging the effective frequency set via non-commuting generators; and (3) a simple heuristic metric based on the trace component of generators, aimed at characterizing training behaviors related to barren plateaus. Simulation experiments on toy problems illustrate the practical implications of the frequency-spectrum perspective and the proposed heuristics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑