We consider a modified gravity plus single scalar-field model, where the scalar Lagrangian couples symmetrically both to the standard Riemannian volume-form (spacetime integration measure density) given by the square-root of the determinant of the Riemannian metric, as well as to another non-Riemannian volume-form in terms of an auxiliary maximal-rank antisymmetric tensor gauge field. The pertinent scalar field dynamics provides an exact unified description of both dark energy via dynamical generation of a cosmological constant, and dark matter as a “dust” fluid with geodesic flow as a result of a hidden Noether symmetry. The associated quantum Wheeler-De Witt equation acquires the form of a Schroedinger-like equation with an effective potential of inverted harmonic oscillator. The quantum average value of the Friedmann-Lemaitre-Robinson-Walker scale factor does not exhibit any singularities in its time evolution thus implying absence of Big Bang creation and supporting the idea of "emerging" universe.
2016, February 20
European Physics Journal C76:90 (2016)