The Quantum Spectral Method: From Atomic Orbitals to Classical Self-Force

Can classical systems be described analytically at all orders in their interaction strength? For periodic and approximately periodic systems, the answer is yes, as we show in this work. Our analytical approach, which we call the $\mathit{\text{Quantum}}\mathit{\text{Spectral}}\mathit{\text{Method}}$, is based on a novel application of Bohr’s correspondence principle, obtaining non-perturbative classical dynamics as the classical limit of $\mathit{\text{quantum}}\mathit{\text{matrix}}\mathit{\text{elements}}$. A major application of our method is the calculation of self-force as the classical limit of atomic radiative transitions. We demonstrate this by calculating an adiabatic electromagnetic inspiral, along with its associated radiation, at all orders in the multipole expansion. Finally, we propose a future application of the Quantum Spectral Method to compute scalar and gravitational self-force in Schwarzschild, analytically.