TY - JOUR AU - Marilena Tzavala AU - J. Kas AU - Lucia Reining AU - John Rehr BT - PHYSICAL REVIEW RESEARCH DO - 10.1103/PhysRevResearch.2.033147 PY - 2020 EP - 033147 T2 - PHYSICAL REVIEW RESEARCH TI - Nonlinear response in the cumulant expansion for core-level photoemission VL - 2 ER -