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arXiv 1610.08070cs.ITmath.ITquant-ph
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从Clifford轨道恢复低秩矩阵

Low rank matrix recovery from Clifford orbits

Richard Kueng, Huangjun Zhu, David Gross

摘要:

我们证明了低秩矩阵可以有效地恢复从少量的测量,从某一矩阵组的轨道采样。作为一种特殊情况,我们的理论对相位恢复问题进行了说明。在这里,任务是恢复一个向量,只给出它的内积的振幅与少量的向量从轨道。在数学的许多领域中,这个群的变体以不同的名字出现。在编码理论和量子信息中,它是复克利福德群;在时频分析中,它是振子群;在数学物理中,它是亚群。它提供了一个特别小的和高度结构化的轨道,包括和推广离散傅立叶基:虽然傅立叶向量具有常数模量的系数和线性依赖于其指数的相位,但所述轨道中的向量具有二次依赖的相位。在量子信息中,轨道被广泛使用,并被称为稳定态的集合。我们认为,由于其丰富的几何结构和接近最佳的恢复性能,稳定状态形成一个理想的模型,相位恢复的结构化测量。我们的结果适用于$m\geq C κ_r r d \log(d)$测量,其中过采样因子k在$κ_r=1$和$κ_r = r^2$之间变化,取决于轨道。重建对加性噪声和偏离低秩假设都是稳定的。如果感兴趣的矩阵是另外半正定的,则可以通过简单的约束最小二乘回归来执行重建。我们的证明方法可以适用于其他群体的轨道。

英文摘要:

We prove that low-rank matrices can be recovered efficiently from a small number of measurements that are sampled from orbits of a certain matrix group. As a special case, our theory makes statements about the phase retrieval problem. Here, the task is to recover a vector given only the amplitudes of its inner product with a small number of vectors from an orbit. Variants of the group in question have appeared under different names in many areas of mathematics. In coding theory and quantum information, it is the complex Clifford group; in time-frequency analysis the oscillator group; and in mathematical physics the metaplectic group. It affords one particularly small and highly structured orbit that includes and generalizes the discrete Fourier basis: While the Fourier vectors have coefficients of constant modulus and phases that depend linearly on their index, the vectors in said orbit have phases with a quadratic dependence. In quantum information, the orbit is used extensively and is known as the set of stabilizer states. We argue that due to their rich geometric structure and their near-optimal recovery properties, stabilizer states form an ideal model for structured measurements for phase retrieval. Our results hold for $m\geq C κ_r r d \log(d)$ measurements, where the oversampling factor k varies between $κ_r=1$ and $κ_r = r^2$ depending on the orbit. The reconstruction is stable towards both additive noise and deviations from the assumption of low rank. If the matrices of interest are in addition positive semidefinite, reconstruction may be performed by a simple constrained least squares regression. Our proof methods could be adapted to cover orbits of other groups.

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。

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