Four-dimensional noncommutative deformations of U(1) gauge theory and L ∞ bootstrap.

We construct a family of four-dimensional noncommutative deformations of U(1) gauge theory following a general scheme, recently proposed in JHEP 08 (2020) 041 for a class of coordinate-dependent noncommutative algebras. This class includes the 𝔰𝔲 (2), the 𝔰𝔲 (1 , 1) and the angular (or λ -Minkowski) noncommutative structures. We find that the presence of a fourth, commutative coordinate x 0 leads to substantial novelties in the expression for the deformed field strength with respect to the corresponding three-dimensional case. The constructed field theoretical models are Poisson gauge theories, which correspond to the semi-classical limit of fully noncommutative gauge theories. Our expressions for the deformed gauge transformations, the deformed field strength and the deformed classical action exhibit flat commutative limits and they are exact in the sense that all orders in the deformation parameter are present. We review the connection of the formalism with the L ∞ bootstrap and with symplectic embeddings, and derive the L ∞ -algebra, which underlies our model.