Replace uniform collocation for a fixed random-feature neural PDE solver with sampling from the leverage-score density of the operator-applied features. Whiten the retained residual feature space before solving for output coefficients, so the sampled least-squares matrix has an identity-like expected Gram rather than inheriting severe anisotropy from the differential operator. The same construction can be used for a linearized neural network by treating Jacobian features as the trial functions.
For bandlimited or progressively higher-frequency targets, construct a nested random Fourier layer whose frequency window grows according to the paper's bandwidth laws instead of sampling all frequencies from one fixed range. Train with a low-bandwidth subset first, then activate additional frequency blocks. This creates a mathematically motivated spectral curriculum and may reduce early optimization difficulty while preserving high-frequency accuracy.
Use spatially correlated training points whose low-frequency structure factor vanishes instead of iid points. For neural fields, PINNs, image-coordinate MLPs, or spatially indexed minibatches, this should suppress long-wavelength quadrature and gradient-estimation noise while preserving the represented target dynamics. The finite-order prediction is that a design with structure factor S(k)=O(|k|^{2q}) produces lower variance for smooth losses than iid sampling, especially as the domain or batch…