On behalf of the Organizing Committee, we are pleased to welcome you to “Frontiers in Ab initio Many-Body Interactions” (FAMBI 2026).

In recent years, first-principles approaches have substantially advanced our ability to investigate many-body interactions in condensed matter systems. These developments now make it possible to quantitatively describe complex phenomena, ranging from electronic correlations to interactions with collective excitations such as phonons, excitons, and magnons, thereby enabling increasingly precise exploration of emergent quantum phases.

As theoretical and computational frameworks continue to improve in accuracy and predictive power, they also grow in complexity. The numerical implementations, methodological details, and algorithmic choices underlying many-body perturbation theory are often too intricate to be fully conveyed through standard conference presentations or publications alone. This has created a need for more focused and in-depth exchange within the community.

The central objective of FAMBI 2026 is to address this need by providing a dedicated forum for researchers actively involved in the development and implementation of computational many-body methods. The workshop is designed to bring together mid-career and early-career scientists who are shaping the next generation of computational tools, with the aim of fostering substantive technical discussions that extend beyond the presentation of results and engage directly with the foundations of the methods themselves.

We look forward to a stimulating and productive workshop, and to the exchange of ideas that will contribute to the continued advancement of computational materials science in the years ahead.