Correction to the response of many-fermion systems and its impulse approximation
摘要
The response function of a many-fermion system, defined via the particle density fluctuations, diverges at very small momentum transfer q. This divergence leads to an unphysical behavior for the response function. We resolve this by introducing a correction term based on time-reversal symmetry. The modified response function is symmetric, well-behaved at low q, and simplifies within the impulse approximation to a form expressed through the momentum distribution. We apply both the original and corrected formulations to interacting nuclear matter. The corrected response function shows improved consistency with experimental data and theoretical definitions, especially when