The Higgs program and open questions in particle physics and cosmology

The Higgs program is relevant to many of the open fundamental questions in particle physics and cosmology. Thus, when discussing future collider experiments, one way of comparing them is by assessing their potential contributions to progress on these questions. We discuss in detail the capabilities of various proposed experiments in searching for singlet scalars, which are relevant to several of the open questions, and in measuring Higgs decays into fermion pairs, which are relevant to the flavor puzzles. With regard to other interesting questions, we list the most relevant observables within the Higgs program.