2016, February 20
European Physics Journal C76:90 (2016)
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.