Brane partons and singleton strings

We examine p  -branes in AdSDAdSD in two limits where they exhibit partonic behavior: rotating branes with energy concentrated to cusp-like solitons; tensionless branes with energy distributed over singletonic bits on the Dirac hypercone. Evidence for a smooth transition from cusps to bits are found. First, each cusp yields D−2D−2 normal-coordinate bound states with protected frequencies; and is dual to a short open p  -brane becoming massless on the giant-vacuum brane at the end-of-the-universe. Second, the NbitNbit-sector is an sp(2Nbit)sp(2Nbit)-gauged phase-space sigma model giving rise to symmetrized NbitNbit-pletons of the minimal higher-spin algebra ho0(D−1,2)⊃so(D−1,2)ho0(D−1,2)⊃so(D−1,2). The continuum limit leads to a 2d chiral sp(2)sp(2)-gauged sigma model which is critical in D=7D=7; equivalent à la Bars–Vasiliev to an su(2)su(2)-gauged spinor string; and furthermore dual to WZW model in turn containing a topological soˆ(6,2)−2/(soˆ(6)⊕soˆ(2))−2 coset model giving rise to a chiral ring generated by singleton-valued weight-0 spin fields. Moreover, the two-bit truncation leads via a reformulation à la Cattaneo–Felder–Kontsevich to a topological open string on the phase space of the D  -dimensional Dirac hypercone giving rise to the Vasiliev equations based on vector oscillators and weak sp(2)sp(2)-projection. Geometrically, the bi-locality reflects broken boundary-singleton worldlines, and the intertwiner κ relates T- and R-ordered deformations of the boundary and the bulk of the worldsheet, respectively.