We introduce and study the derived moduli stack Symp(X,n) of
n-shifted symplectic structures on a given derived stack X, as introduced
by [PTVV] (IHES Vol. 117, 2013). In particular, under reasonable assumptions on
X, we prove that Symp(X,n) carries a canonical shifted quadratic
form. This generalizes a classical result of Fricke and Habermann, which was
established in the C∞-setting, to the broader context of derived
algebraic geometry, thus proving a conjecture stated by Vezzosi.Comment: 17 page