Abstract: Variational inference with natural-gradient descent often shows fast convergence in practice, but its theoretical convergence guarantees have been challenging to establish. This is true even for the simplest cases that involve concave log-likelihoods and use a Gaussian approximation. We show that the challenge can be circumvented for such cases using a square-root parameterization for the Gaussian covariance. This approach establishes novel convergence guarantees for natural-gradient variational-Gaussian inference and its continuous-time gradient flow. Our experiments demonstrate the effectiveness of natural gradient methods and highlight their advantages over algorithms that use Euclidean or Wasserstein geometries.
Submission Length: Regular submission (no more than 12 pages of main content)
Changes Since Last Submission: Section 7 is brand new, section 8 is rephrased and has been expanded a bit.
Assigned Action Editor: ~Jan-Willem_van_de_Meent1
Submission Number: 3805
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