Generalizing metastability theory to interacting bosonic models

Investigate and develop a rigorous theory of metastability for interacting bosonic systems, particularly beyond number-conserving settings where strong locality bounds are unavailable. Determine conditions under which Lieb–Robinson-type control suffices, and devise new techniques to establish metastable lifetimes and local diagonalizability in bosonic models without conserved particle number.

Background

The paper’s results rely on strong locality bounds and Lieb–Robinson-type estimates, which are well-established for finite-dimensional spin systems and, in some cases, for number-conserving bosons. Extending the metastability framework to generic bosonic models is challenging because strong locality bounds can fail without number conservation.

The authors explicitly flag this extension as an open question. Addressing it would significantly broaden the applicability of metastability theory to many experimentally relevant bosonic systems, requiring new analytical tools beyond current locality frameworks.