Phase transitions in atomic nuclei

Numerous examples show phase transitions in the structure of atomic nuclei as the excitation energy and the moment of rotation increase and the number of nucleons changes. These are phase transitions of the equilibrium shape and structure of the ground and low-lying excited states of the nuclei, associated with a change in their symmetry. The subject of phase transitions has given rise to a new wave of investigations into the structure of atomic nuclei. In this review, we consider examples of phase transitions, discuss the feasibility of describing them within a collective model of the nucleus with a Hamiltonian depending on a small number of dynamic variables, and also touch upon microscopic aspects of phase transitions.