Extend the Killing initial data characterization beyond analytic asymptotic data

Establish the converse Killing initial data theorem for smooth, non-analytic asymptotic data in higher dimensions: namely, prove that a conformal Killing vector field satisfying the Killing initial data equation extends uniquely to a bulk Killing vector for the associated positive-cosmological-constant vacuum spacetime.

Background

The paper uses a higher-dimensional Killing initial data theorem whose converse is established only for analytic asymptotic data. In that result, a conformal Killing vector satisfying the boundary Killing initial data equation determines a unique bulk Killing vector. Extending this implication to the smooth non-analytic category would provide a general characterization of bulk symmetries directly from asymptotic data and would remove the analyticity restriction from the framework used to study asymptotic Killing horizons.

References

The Theorem is expected to hold beyond the analytic class of data, although up to the author's knowledge, no formal proof has yet been established.

— Asymptotics of Killing horizons: A Characterization in de Sitter Spacetime  (2609.37427 - Peón-Nieto, 29 Sep 2026) in Remark immediately following Theorem KIDanal, Section 2.3 (Killing initial data)