  Positive geometries encode the physics of scattering amplitudes in flat
space-time and the wavefunction of the universe in cosmology for a large class
of models. Their unique canonical forms, providing such quantum mechanical
observables, are characterised by having only logarithmic singularities along
all the boundaries of the positive geometry. However, physical observables have
logarithmic singularities just for a subset of theories. Thus, it becomes
crucial to understand whether a similar paradigm can underlie their structure
in more general cases. In this paper we start a systematic investigation of a
geometric-combinatorial characterisation of differential forms with
non-logarithmic singularities, focusing on projective polytopes and related
meromorphic forms with multiple poles. We introduce the notions of covariant
forms and covariant pairings. Covariant forms have poles only along the
boundaries of the given polytope; moreover, their leading Laurent coefficients
along any of the boundaries are still covariant forms on the specific boundary.
Whereas meromorphic forms in covariant pairing with a polytope are associated
to a specific (signed) triangulation, in which poles on spurious boundaries do
not cancel completely, but their order is lowered. These meromorphic forms can
be fully characterised if the polytope they are associated to is viewed as the
restriction of a higher dimensional one onto a hyperplane. The canonical form
of the latter can be mapped into a covariant form or a form in covariant
pairing via a covariant restriction. We show how the geometry of the higher
dimensional polytope determines the structure of these differential forms.
Finally, we discuss how these notions are related to Jeffrey-Kirwan residues
and cosmological polytopes.
