Carroll covariant scalar fields in two dimensions

A bstract Conformal Carroll symmetry generically arises on null manifolds and is important for holography of asymptotically flat spacetimes, generic black hole horizons tensionless strings. In this paper, we focus two dimensional (2 d ) hence the 2 or equivalently 3 Bondi-Metzner-Sachs (BMS) algebra. Using covariance, write most general free massless scalar field theory discover three inequivalent actions . Of these, viz. time-like space-like actions, have made their appearance in literature before. We uncover a third that call mixed-derivative theory. As expected, all theories enjoy off-shell BMS invariance. Interestingly, find on-shell mixed derivative single Virasoro algebra instead full BMS. discuss potential applications to strings holography.