Highly elongated polymer melts in the non-linear viscoelastic regime are characterized, specifically the interplay between topological constraints and macroscopic stress are examined.

• Microscopic Validation of Tube-Model Dynamics: Large-scale molecular dynamics simulations provide direct evidence of the chain retraction signature following strong elongational deformation. This work confirms core predictions of the Doi-Edwards and GLaMM models by demonstrating that stretched chains contract in all spatial directions within their affinely deformed tubes immediately after the strain is applied.

"Chain retraction in highly entangled stretched polymer melts", arXiv:1805.01935, Phys. Rev. Lett.  121, 167801 (2018).

• Topological Inhomogeneity and Entanglement Clustering: A significant discovery is the emergence of long-lived entanglement clusters in strongly deformed states. This inhomogeneous distribution acts as a persistent constraint that significantly retards conformational relaxation compared to equilibrium predictions

"Clustering of entanglement points in highly strained polymer melts", arXiv:190600109, Macromoelcules 52, 6756-6772 (2019).

• Load Bearing and Primitive Path Tension: By applying primitive path analysis (PPA), the tension profile along the chain backbones  is identified. This work demonstrates that the macroscopic stress is directly linked to the local density of entanglements and how they are distributed after deformation.