Mixtures of Gaussians are Privately Learnable with a Polynomial Number of Samples
- URL: http://arxiv.org/abs/2309.03847v3
- Date: Tue, 23 Apr 2024 14:54:23 GMT
- Title: Mixtures of Gaussians are Privately Learnable with a Polynomial Number of Samples
- Authors: Mohammad Afzali, Hassan Ashtiani, Christopher Liaw,
- Abstract summary: We study the problem of estimating mixtures of Gaussians under the constraint of differential privacy (DP)
Our main result is that $textpoly(k,d,1/alpha,1/varepsilon,log (1/delta))$ samples are sufficient to estimate a mixture of $k$ Gaussians in $mathbbRd$ up to total variation distance $alpha$.
This is the first finite sample complexity upper bound for the problem that does not make any structural assumptions on the GMMs.
- Score: 9.649879910148854
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We study the problem of estimating mixtures of Gaussians under the constraint of differential privacy (DP). Our main result is that $\text{poly}(k,d,1/\alpha,1/\varepsilon,\log(1/\delta))$ samples are sufficient to estimate a mixture of $k$ Gaussians in $\mathbb{R}^d$ up to total variation distance $\alpha$ while satisfying $(\varepsilon, \delta)$-DP. This is the first finite sample complexity upper bound for the problem that does not make any structural assumptions on the GMMs. To solve the problem, we devise a new framework which may be useful for other tasks. On a high level, we show that if a class of distributions (such as Gaussians) is (1) list decodable and (2) admits a "locally small'' cover (Bun et al., 2021) with respect to total variation distance, then the class of its mixtures is privately learnable. The proof circumvents a known barrier indicating that, unlike Gaussians, GMMs do not admit a locally small cover (Aden-Ali et al., 2021b).
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