Infrared fixed point

In the context of quantum field theory and statistical physics, an "infrared fixed point" refers to a particular type of fixed point in the renormalization group flow where the behavior of the system at long wavelengths (or low energies) becomes scale-invariant. This means that, as one examines the system at larger and larger scales or lower and lower energies, the physical properties of the system do not change—they remain self-similar.