We construct the Cartan calculus of differential cubical forms on an object of a cartesian tangent category with a scalar multiplication by a commutative ring object . Borrowing the terminology of cubical singular homology, we define an (infinitesimal) cubical -form to be a morphism on the iterated tangent bundle that is antisymmetric and -linear in every factor of . We call differential if, in addition, it is its own derivative in the fiber directions. (This notion of forms is a special case of the singular forms of Cruttwell and Lucyshyn-Wright.) We prove that the differential cubical forms are naturally equipped with the structure of a commutative differential graded algebra (CDGA). Then we show that, if the ring object has no -torsion, this CDGA together with the Lie algebra of vector fields and the inner derivatives constitutes a Cartan calculus. It lies between their initial Cartan calculus of algebraic Kähler forms and the terminal one of Lie-Rinehart forms. We give a number of examples. In particular, on affine schemes over a field of characteristic other than two and on elastic diffeological spaces we retrieve the usual de Rham complex, which is generally different from the complex of Lie-Rinehart forms.

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