On the Sample Complexity of Learning with Geometric Stability

Many supervised learning problems involve high-dimensional data such as images, text, or graphs. In order to make efficient use of data, it is often useful to leverage certain geometric priors in the problem at
hand, such as invariance to translations, permutation subgroups, or stability to small deformations. We study the sample complexity of learning problems where the target function presents such invariance and stability properties, by considering spherical harmonic decompositions of such functions on the sphere. We provide non-parametric rates of convergence for kernel methods, and show improvements in sample complexity by a factor equal to the size of the group when using an invariant kernel over the group, compared to the
corresponding non-invariant kernel. These improvements are valid when the sample size is large enough, with an asymptotic behavior that depends on spectral properties of the group. Finally, these gains are
extended beyond invariance groups to also cover geometric stability to small deformations, modeled here as subsets (not necessarily subgroups) of permutations.

Join Zoom Meeting
https://maths-cam-ac-uk.zoom.us/j/98587671557?pwd=eGthTEU5TVdNcUt0bldQREhMaVhMZz09

Meeting ID: 985 8767 1557
Passcode: 169824

• Speaker: Alberto Bietti (NYU)
• Wednesday 09 February 2022, 14:00–15:00
• Venue: Virtual (Zoom details under abstract).
• Series: CCIMI Seminars; organiser: Willem Diepeveen.