Reflected constraint algebras of open Carroll--Weyl null strings

Abstract

We construct a classical reflected phase space for open Carroll--Weyl null strings with Dirichlet conditions at the target origin or linear mixed target gluings. The reflection-compatible constraints are differentiable, their Hamiltonian flows preserve the boundary domain, and the constraint system is weakly first class on its regular part. The induced boundary algebra extends the boundary Carrollian conformal algebra by an even weight-one Carroll--Weyl current, with normalization fixed by the reflected symplectic form. The regular local embedding count agrees with that of the closed theory. We exhibit a four-dimensional mixed sector with one canonical field pair and a separate solution family carrying a nonzero conserved target-space boost charge and a nondegenerate symplectic pullback. Smooth fixed-point reflection selects characteristic endpoints. For timelike defects with natural tangential variations and no additional boundary interactions, non-characteristic endpoints have vanishing Carroll flow. For displaced Dirichlet data, we derive the canonical affine lift and its required shift of the edge momentum by integrated bulk momentum.