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arXiv · 2510.01610

Higher moment theory and learnability of bosonic states

Joseph T. Iosue·Yu-Xin Wang·Ishaun Datta·Soumik Ghosh·Changhun Oh·Bill Fefferman·Alexey V. Gorshkov
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Abstract

We present a sample- and time-efficient algorithm to learn any bosonic Fock state acted upon by an arbitrary Gaussian unitary. As a special case, this algorithm efficiently learns states produced in Fock state BosonSampling, thus resolving an open question put forth by Aaronson and Grewal (Aaronson, Grewal 2023). We further study a hierarchy of classes of states beyond Gaussian states that are specified by a finite number of their higher moments. Using the higher moments, we find a full spectrum of invariants under Gaussian unitaries, thereby providing necessary conditions for two states to be related by an arbitrary (including active, e.g. beyond linear optics) Gaussian unitary.

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Joseph T. Iosue, Yu-Xin Wang, Ishaun Datta, Soumik Ghosh, Changhun Oh, Bill Fefferman, Alexey V. Gorshkov. 2025-10-02. Higher moment theory and learnability of bosonic states. https://arxiv.org/abs/2510.01610

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