Canonical coordinates are defined as a special set of coordinates on the cotangent bundle of a manifold. They are usually written as a set of ( q i , p j ) {\displaystyle \left(q^{i},p_{j}\right)} or ( x i , p j ) {\displaystyle \left(x^{i},p_{j}\right)} with the x's or q's denoting the coordinates on the underlying manifold and the p's denoting the conjugate momentum, which are 1-forms in the cotangent bundle at point q in the manifold.