The goal of the ULTRA BSE project is to obtain a deep understanding of the low-energy elementary electronic excitations that can be measured by inelastic scattering experiments in correlated materials.It will push forward the ability of first-principles many-body methods to deal with correlated materials and will foster their integration with experiments.The outcome of ULTRA BSE will be a set of new ab initio theoretical tools capable to guide new experiments on correlated materials with the aim of realising their potential for novel nanoscale devices beyond the limits of today’s electronics.The research budget will be used to support the integration of M. Gatti as permanent CNRS researcher at the Laboratoire des Solides Irradiés (LSI), including cofunding a PhD fellowship.It will create the best possible conditions for establishing the applicant in the new stable research career as leader of an independent theoretical team working at a synchrotron facility.Finally, it will strengthen ongoing international collaborations with colleagues working in the fields of synchrotron and theoretical spectroscopies (notably with his former group in San Sebastian, Spain).