Quantum kernels

Umbrella module for the quantum-kernel development; re-exports the genuine results.

• QKernel.Fidelity — the fidelity quantum kernel and its Gram-matrix positive semidefiniteness (quantumKernel_gram_posSemidef).
• QKernel.Fourier — the Fourier representation of quantum kernels (fourier_representation, Schuld 2021).
• QKernel.Concentration — exponential concentration of the tensor-product RY kernel (ryKernel_concentrates, Thanasilp 2022).
• QKernel.DiscreteLogConcept / QKernel.Advantage — the discrete-log concept class (secret-homogeneity acc_shift) and the conditional learning-advantage separation (QuantumKernelAdvantage.separation, Liu 2021).
• QKernel.Expressivity — density-matrix realization of feature-map kernels (eqk_realizes, Gil-Fuster 2023).