A structural approach to theoretical physics reveals that genuine cosmological models must be relational in a manner that is roughly laid out in Leibniz’s framework of monadology. In an event ontology, this has the implication that there cannot be global symmetries in spacetime, which is verified for compact cosmological solutions in general relativity. However, since spacetime and 4-momentum are dynamically paired in a Hamiltonian treatment, it is possible to interpret 4-momentum as an intrinsic quantity that nonetheless has causal efficacy, thus motivating the energetic causal sets program even in classical cosmology.
This form of impure relationalism further allows the possibility of a preferred, irreducible notion of universal time and reference frames only measurable at the cosmic scale, thereby compatible with the empirical findings of general relativity while opening the possibility of describing a fundamental theory from which general relativity and quantum mechanics may emerge for special subsystems and levels of organization.