Euler-scale hydrodynamics without attractiveness

Prove hydrodynamic limits at Euler scaling for asymmetric interacting particle systems with drift that neither satisfy the basic coupling nor possess the attractiveness property.

Background

The relative entropy argument is presented for TASEP, an attractive asymmetric exclusion process, and relies on a one-block estimate. The notes state that hydrodynamics for all times can be obtained for attractive processes by other methods.

For general drifted processes lacking attractiveness, the corresponding all-time Euler-scale hydrodynamic limit remains unresolved. Establishing such a result would extend the theory beyond the class where the basic coupling provides the required comparison and local-equilibrium estimates.

References

However, in general, hydrodynamics for all times has not been shown for processes with drift in Euler scale \upsilon(N)=N that do not satisfy the basic coupling' or are notattractive' in the sense given in Subsection \ref{coupling}. It is an open problem to show such hydrodynamics.

Notes on Hydrodynamic Limits and Related Topics  (2608.20252 - Sethuraman, 20 Aug 2026) in Section 6, Notes