Beltran, JarnishsFarinati, MarcoReyes, Enrique G.2018-02-222018-02-222017Journal of Pure and Applied Algebra Available online 8 August 2017http://hdl.handle.net/11447/1994https://doi.org/10.1016/j.jpaa.2017.08.017Get rights and contentWe describe the space of central extensions of the associative algebra Ψn of formal pseudo-differential symbols in n≥1 independent variables using Hochschild (co)homology groups: we prove that the first Hochschild (co)homology group HH1(Ψn) is 2n-dimensional and we use this fact to calculate the first Lie (co)homology group HLie1(Ψn) of Ψn equipped with the Lie bracket induced by its associative algebra structure. As an application, we use our calculations to provide examples of infinite-dimensional quadratic symplectic Lie algebras.Available onlineen-USArtículo