Abstract

Globular clusters are among the most ancient and densest stellar systems known. They pack millions of old stars within just a few parsecs, representing truly unique objects in the Universe. Associated with galaxies of all type and mass, globular clusters are intrinsically connected to the earliest formation of galaxies and dark matter halos. On the other hand, young progenitors of globular-cluster-like objects are observed in galactic mergers and dense star forming regions within nearby galaxies. This connection to current star formation suggests that globular clusters probe not only the large-scale environment of galaxies and halos, but also the small-scale physics of star formation and stellar feedback on the interstellar medium. The purpose of this program is to establish a transformative cross-talk between the different fields of astrophysics linked by the physics of globular clusters. The program will highlight and establish the link between old globular clusters and young star clusters in the Local Universe, their connection to galaxy formation and supermassive black holes, and their role in the physics of the early Universe and the reionization of cosmic hydrogen.