Description
We outline the prospective contributions of functional methods towards hadron spectroscopy and structure calculations within the NuPECC Long Range Plan 2024. Based on a body of existing work, this approach offers opportunities towards a microscopic description of ordinary as well as exotic hadrons such as glueballs, hybrid mesons, tetraquarks, pentaquarks and even light nuclei. Functional methods have come to a stage where ab-initio calculations based on self-consistent solutions for the microscopic quark and gluon n-point correlation functions have come within reach. In the near future, the existing high-quality calculations for glueballs and light mesons will be extended towards a wide range of observables and provide access to ordinary and exotic hadron spectroscopy, the timelike properties of hadrons, the internal structure of hadrons through parton distributions, and flavor matrix elements to pin down QCD contributions in searches for new physics.