Sample-Efficient Private Learning of Mixtures of Gaussians
- URL: http://arxiv.org/abs/2411.02298v1
- Date: Mon, 04 Nov 2024 17:23:52 GMT
- Title: Sample-Efficient Private Learning of Mixtures of Gaussians
- Authors: Hassan Ashtiani, Mahbod Majid, Shyam Narayanan,
- Abstract summary: We prove that roughly $kd2 + k1.5 d1.75 + k2 d$ samples suffice to learn a mixture of $k$ arbitrary $d$-dimensional Gaussians.
Our work improves over the previous best result [AAL24b] and is provably optimal when $d$ is much larger than $k2$.
- Score: 11.392841244701605
- License:
- Abstract: We study the problem of learning mixtures of Gaussians with approximate differential privacy. We prove that roughly $kd^2 + k^{1.5} d^{1.75} + k^2 d$ samples suffice to learn a mixture of $k$ arbitrary $d$-dimensional Gaussians up to low total variation distance, with differential privacy. Our work improves over the previous best result [AAL24b] (which required roughly $k^2 d^4$ samples) and is provably optimal when $d$ is much larger than $k^2$. Moreover, we give the first optimal bound for privately learning mixtures of $k$ univariate (i.e., $1$-dimensional) Gaussians. Importantly, we show that the sample complexity for privately learning mixtures of univariate Gaussians is linear in the number of components $k$, whereas the previous best sample complexity [AAL21] was quadratic in $k$. Our algorithms utilize various techniques, including the inverse sensitivity mechanism [AD20b, AD20a, HKMN23], sample compression for distributions [ABDH+20], and methods for bounding volumes of sumsets.
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