Spherical model

The spherical model is a mathematical framework used in statistical physics to study magnetic systems, where particles can have spins that interact with neighbors. Unlike simpler models that restrict spins to specific directions, the spherical model treats these spins as continuous variables constrained to lie on a sphere—meaning their squared values sum to a constant. This approach simplifies calculations while capturing essential features of phase transitions and critical behavior. Overall, it provides insights into how collective properties emerge in complex systems by allowing mathematical flexibility with a realistic physical constraint.