Cause of mode-coupling theory failure at its predicted transition

Establish the theoretical reason why standard mode-coupling theory predicts a non-ergodicity transition at its critical temperature (T_MCT) that is not observed in simulations and experiments, leading to the breakdown of the theory below T_MCT.

Background

Mode-coupling theory successfully captures many qualitative features of glassy dynamics but predicts a sharp non-ergodicity transition at T_MCT that is absent in real systems.

Understanding the origin of this failure is pivotal for refining theoretical descriptions of glass formation and for extending them reliably to active systems.

References

The reason behind this failure of MCT remains unclear.

— A perspective on active glassy dynamics in biological systems  (2403.06799 - Sadhukhan et al., 2024) in Section 5.1, Mode-coupling theory of active glasses (equilibrium MCT context)

Whether this evolution connects continuously to the mosaic-driven processes advocated by theories of the deeply supercooled regime, and how the two lengthscales governing these respective regimes relate to one another , are questions that we hope the present work will motivate.

— Non-Monotonic Dynamical Correlations Across The Glass Crossover  (2608.21219 - Laudicina et al., 21 Aug 2026) in Section 4, Discussion