Caroca, R., Concha, P., Rodriguez, E., & SalgadoRebolledo, P. (2018). Generalizing the bms(3) and 2Dconformal algebras by expanding the Virasoro algebra. Eur. Phys. J. C, 78(3), 15 pp.
Abstract: By means of the Lie algebra expansion method, the centrally extended conformal algebra in two dimensions and the bms3 algebra are obtained from the Virasoro algebra. We extend this result to construct new families of expanded Virasoro algebras that turn out to be infinitedimensional lifts of the socalled Bk, Ck and Dk algebras recently introduced in the literature in the context of (super) gravity. We also show how some of these new infinitedimensional symmetries can be obtained from expanded KacMoody algebras using modified Sugawara constructions. Applications in the context of threedimensional gravity are briefly discussed.

Caroca, R., Concha, P., Fierro, O., Rodriguez, E., & SalgadoRebolledo, P. (2018). Generalized ChernSimons higherspin gravity theories in three dimensions. Nucl. Phys. B, 934, 240–264.
Abstract: The coupling of spin3 gauge fields to threedimensional Maxwell and AdSLorentz gravity theories is presented. After showing how the usual spin3 extensions of the Ad S and the Poincare algebras in three dimensions can be obtained as expansions of sl (3, R) algebra, the procedure is generalized so as to define new higherspin symmetries. Remarkably, the spin3 extension of the Maxwell symmetry allows one to introduce a novel gravity model coupled to higherspin topological matter with vanishing cosmological constant, which in turn corresponds to a flat limit of the AdSLorentz case. We extend our results to define two different families of higherspin extensions of threedimensional Einstein gravity. (C) 2018 The Authors. Published by Elsevier B.V.
