We review the role and properties of hyperons in finite and infinite nuclear systems. In particular, we present different production mechanisms of hypernuclei, as well as several aspects of hypernuclear γ-ray spectroscopy, and the weak decay modes of hypernuclei. Then we discuss the construction of hyperon-nucleon and hyperon-hyperon interactions on the basis of the meson-exchange and chiral effective field theories. Recent developments based on the so-called V low k approach and lattice quantum chromodynamics will also be addressed. Finally, we go over some of the effects of hyperons on the properties of neutron and proto-neutron stars with an emphasis on the so-called 'hyperon puzzle', i.e. the problem of the strong softening of the equation of state, and the consequent reduction of the maximum mass, induced by the presence of hyperons, a problem which has become more intriguing and difficult to solve due the recent measurements of approximately 2M ⊙ millisecond pulsars. We discuss some of the solutions proposed to tackle this problem. We also re-examine the role of hyperons on the cooling properties of newly born neutron stars and on the development of the so-called r-mode instability.
Keywords: baryon–baryon interactions; equation of state; hypernuclei; hyperons; neutron star.