  Our primary objective is to construct a plausible unified model of inflation,
dark energy and dark matter from a fundamental Lagrangian action first
principle, where all fundamental ingredients are systematically dynamically
generated starting from a very simple model of modified gravity interacting
with a single scalar field employing the formalism of non-Riemannian spacetime
volume-elements. The non-Riemannian volume element in the initial scalar field
action leads to a hidden nonlinear Noether symmetry which produces
energy-momentum tensor identified as a sum of a dynamically generated
cosmological constant and a dust-like dark matter. The non-Riemannian
volume-element in the initial Einstein-Hilbert action upon passage to the
physical Einstein-frame creates dynamically a second scalar field with a
non-trivial inflationary potential and with an additional interaction with the
dynamically generated dark matter. The resulting Einstein-frame action
describes a fully dynamically generated inflationary model coupled to dark
matter. Numerical results for observables such as the scalar power spectral
index and the tensor-to-scalar ratio conform to the latest 2018 PLANCK data.
