Weyl-Cartan-Weitzenböck gravity as a generalization of teleparallel gravity

Journal Article · Mon Oct 01 00:00:00 EDT 2012 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2012/10/061· OSTI ID:22279670

Haghani, Zahra; Sepangi, Hamid Reza; Shahidi, Shahab ^[1]; Harko, Tiberiu ^[2]

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1. Department of Physics, Shahid Beheshti University, G.C., Evin,Tehran 19839 (Iran, Islamic Republic of)
2. Department of Physics and Center for Theoretical and Computational Physics, The University of Hong Kong, Pok Fu Lam Road, Hong Kong (China)

We consider a gravitational model in a Weyl-Cartan space-time in which the Weitzenböck condition of the vanishing of the sum of the curvature and torsion scalar is imposed. In contrast to the standard teleparallel theories, our model is formulated in a four-dimensional curved spacetime. The properties of the gravitational field are then described by the torsion tensor and Weyl vector fields. A kinetic term for the torsion is also included in the gravitational action. The field equations of the model are obtained from a Hilbert-Einstein type variational principle, and they lead to a complete description of the gravitational field in terms of two fields, the Weyl vector and the torsion, respectively, defined in a curved background. The cosmological applications of the model are investigated for a particular choice of the free parameters in which the torsion vector is proportional to the Weyl vector. The Newtonian limit of the model is also considered, and it is shown that the Poisson equation can be recovered in the weak field approximation. Depending on the numerical values of the parameters of the cosmological model, a large variety of dynamic evolutions can be obtained, ranging from inflationary/accelerated expansions to non-inflationary behaviors. In particular we show that a de Sitter type late time evolution can be naturally obtained from the field equations of the model. Therefore the present model leads to the possibility of a purely geometrical description of the dark energy, in which the late time acceleration of the Universe is determined by the intrinsic geometry of the space-time.

• OSTI ID: 22279670
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
APPROXIMATIONS
COSMOLOGICAL MODELS
COSMOLOGY
DE SITTER GROUP
DE SITTER SPACE
FIELD EQUATIONS
FOUR-DIMENSIONAL CALCULATIONS
GRAVITATIONAL FIELDS
NONLUMINOUS MATTER
POISSON EQUATION
SCALARS
SPACE-TIME
TORSION
UNIVERSE
VARIATIONAL METHODS
VECTOR FIELDS