Represent a rotation-dependent scalar or feature field by truncated Wigner-D coefficients and apply Lie derivatives, gradients, and divergence using fixed generator matrices in frequency space. This replaces noisy coordinate-space finite differences and gives an exactly band-limited rotational differential layer with predictable computational cost.
Replace a dense Haar or Gaussian random projection with a streamed product of random two-coordinate rotations followed by coordinate subsampling. The transform is exactly orthogonal before subsampling, requires only a list of rotation triples, and the paper's pseudo-mixing result predicts that degree-two statistics relevant to norm preservation and Johnson–Lindenstrauss embeddings become Haar-like after only O(n polylog(n)) rotations.
Initialize a unitary feature-mixing layer with a shallow brickwork circuit of independent random SU(4) gates instead of sampling or factorizing a dense Haar-random unitary. Stack enough layers to obtain a target contraction of non-Haar components, using the paper's constant spectral-gap principle to make the required depth essentially independent of the number of qubits. The resulting layer is local, parameter-efficient, exactly norm-preserving, and should provide Haar-like scrambling at…
Replace all pairwise consistency comparisons between m augmented views by a single group-valued relative-difference vector with m−1 components. Add a learned contractible-chart penalty so that the relative-difference map remains locally simple rather than merely numerically small. The construction is invariant to simultaneous left multiplication of every view, providing a useful gauge-invariant consistency signal.