Are there really conformal frames? Uniqueness of affine inflation

Understand

Here we concisely review the nonminimal coupling dynamics of a single scalar field in the context of purely affine gravity and extend the study to multifield dynamics.

• The coupling is performed via an affine connection and its associated curvature without referring to any metric tensor.
• The latter arises a posteriori and it may gain an emergent character like the scale of gravity.
• What is remarkable in affine gravity is the transition from nonminimal to minimal couplings which is realized by only field redefinition of the scalar fields.