2016/08/01 by Hatice Özer, Ahmet Baykal, Özgür Delice · 3 citations
Mathematics · Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Curvature #Einstein #Gauss–Bonnet gravity #Geometry #Mathematical physics #Mathematics #Minimal coupling #Physics #Scalar curvature #Scalar field #gr-qc
paper · pdf · doi:10.1140/epjp/i2016-16290-4
published in The European Physical Journal Plus 131(8) (Springer Science+Business Media) · 17 pages
openalex publication_date 2016/08/01 · arxiv created 2016/08/29 · arxiv updated 2016/08/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A modified Einstein-Gauss-Bonnet gravity in four dimensions where the quadratic Gauss-Bonnet term is coupled to a scalar field is considered. The field equations of the model are obtained by variational methods by making use of the constrained-first order formalism covering both pseudo-Riemannian and non-Riemannian cases. In the pseudo-Riemannian case, the Lagrange multiplier forms, which impose the vanishing torsion constraint, are eliminated in favor of the remaining fields and the resulting metric field equations are expressed in terms of the double-dual curvature 2-form. In the non-Riemannian case with torsion, the field equations are expressed in terms of the pseudo-Riemannian quantities by a perturbative scheme valid for a weak coupling constant. It is shown that, for both cases, the model admits a maximally symmetric de-Sitter solution with nontrivial scalar field. Minimal coupling of a Dirac spinor to the Gauss-Bonnet modified gravity is also discussed briefly.