2014/05/31 by Tiberiu Harko, Francisco S. N. Lobo, Giovanni Otalora +2 路 5 citations
Physics and Astronomy 路 #Black Holes and Theoretical Physics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Curvature #Dark energy #De Sitter universe #Galaxies: Formation, Evolution, Phenomena #General relativity #Geometry #Gravitation #Graviton #Massive gravity #Mathematical physics #Physics #Quantum mechanics #Quintessence #Scalar (mathematics) #Scalar curvature #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-th
paper 路 pdf 路 doi:10.1088/1475-7516/2014/12/021
published as JCAP 12 (2014) 021 路 31 pages, 15 figures; matches published version
arxiv created 2014/12/11 路 openalex publication_date 2014/12/11 路 arxiv updated 2014/12/12 路 openalex created_date 2016/06/24 路 openalex updated_date 2026/08/05
We present an extension of f ( T ) gravity, allowing for a general coupling of the torsion scalar T with the trace of the matter energy-momentum tensor . The resulting f ( T , ) theory is a new modified gravity, since it is different from all the existing torsion or curvature based constructions. Applied to a cosmological framework, it leads to interesting phenomenology. In particular, one can obtain a unified description of the initial inflationary phase, the subsequent non-accelerating, matter-dominated expansion, and then the transition to a late-time accelerating phase. Additionally, the effective dark energy sector can be quintessence or phantom-like, or exhibit the phantom-divide crossing during the evolution. Moreover, in the far future the universe results either to a de Sitter exponential expansion, or to eternal power-law accelerated expansions. Finally, a detailed study of the scalar perturbations at the linear level reveals that f ( T , ) cosmology can be free of ghosts and instabilities for a wide class of ansatzes and model parameters.