AT2 - Extended Theories of Gravity and Quantum Cosmology |
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Speaker |
Izaurieta, Fernando |
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Coauthors |
Cordonier, Fabrizio; Medina, Perla; Narbona, Daniela; Rodriguez, Eduardo, Valdivia, Omar |
| Talk Title |
Horndeski Lagrangian, Cartan Geometry and Torsion |
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Abstract |
Scalar fields are a common tool in the context of inflation. In comparison, torsion is scarcely used in the context of cosmology. However, recent works have shown that non-vanishing torsion has highly non-trivial cosmological consequences [1, 2, 3]. When torsion vanishes, the most general lagrangian for gravity coupled to an scalar field in d = 4 (providing second order equations of motion) is given by the Horndeski lagrangian [4, 5]. In this talk we will study how to write down the Horndeski 4-form lagrangian in first order formalism with non-vanishing torsion. In particular, we will study how non-minimal couplings in Horndeski's theory generate torsion and affect cosmological evolution. References [1] N. Poplawski, Cosmology with torsion: An alternative to cosmic inflation, Phys. Lett. B 694 (3): 181–185 (2010). arXiv:1007.0587 [2] N. Poplawski, Nonsingular, big-bounce cosmology from spinor-torsion coupling, Phys. Rev. D 85 (10): 107502 (2012). arXiv:1111.4595 [3] A. Toloza, J. Zanelli, Cosmology with scalar–Euler form coupling, Class.Quant.Grav. 30 (2013) 135003, arXiv:1301.0821 [4] G. Horndeski, Second-Order Scalar-Tensor Field Equations in a Four-Dimensional Space, Int. J. Theor. Phys. 10, No. 6 (1974), pp. 363-384 [5] T. Kobayashi, M. Yamaguchi, J. Yokoyama, Generalized G-inflation: Inflation with the most general second-order field equations, Prog. Theor. Phys. 126 (2011), 511-529, arXiv:1105.5723 [hep-th] |
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