  Affine gravity, a gravity theory based on affine connection with no notion of
metric, supports scalar field dynamics only if scalar fields have non-vanishing
potential. The non-vanishing vacuum energy ensures that the cosmological
constant is non-vanishing. It also ensures that the energy-momentum tensor of
vacuum gives the dynamically generated metric tensor. We construct this affine
setup and study primordial inflation in it. We study inflationary dynamics in
affine gravity and general relativity, comparatively. We show that
non-minimally coupled inflaton dynamics can be transformed into a
minimally-coupled one with a modified potential. We also show that there is one
unique frame in affine gravity, as opposed to the Einstein and Jordan frames in
general relativity. Future observations with higher accuracy may be able to
test the affine gravity.
