Assess energy-conservation enforcement versus unit-cell averaging in CQSFA

Ascertain whether manually imposing the energy-conservation condition n·ω = E_p + U_p + I_p on photoelectron momentum distributions computed with the Coulomb Quantum-Orbit Strong-Field Approximation provides better agreement with experiments than unit-cell averaging, and identify the specific improvements and the physical reasons underlying any superiority of one approach over the other.

Background

Unit-cell averaging has been successfully used in prior CQSFA studies to compare theory with experiments, achieving excellent agreement for fine features such as spider-like holographic modulations, with additional filtering applied to remove high-frequency oscillations like ATI rings.

This paper proposes enforcing energy conservation directly when using saddle-point methods to obtain physically consistent, unique momentum distributions. Whether this condition outperforms unit-cell averaging for CQSFA comparisons to experiments, and why, remains explicitly posed as an open issue by the authors.