Astrophysical and cosmological applications of modified theories of gravity
Details

Call:
IDPASC Portugal  PHD Programme 2015

Academic Year:
2015 / 2016

Domains:
General Relativity  Cosmology

Supervisor:
José Sande Lemos

CoSupervisor:
Francisco Lobo

Institution:
Instituto Superior Técnico

Host Institution:
Instituto Superior Técnico

Abstract:
The latetime cosmic accelerated expansion is one of the most important and challenging current problems in cosmology. Although the standard model of cosmology has favored the dark energy models as fundamental candidates responsible for the cosmic expansion, the latter may be due to modifications of General Relativity, which introduce new degrees of freedom to the gravitational sector itself. This research project will explore the viability of a plethora of modified gravity models, consistently analyzing the reproduction of all the cosmological epochs. More specifically, we will consider generalizations of the EinsteinHilbert action by including quadratic Lagrangians, involving second order curvature invariants, such as Lagrangians involving nonlinear curvature invariants, such as, modified GaussBonnet theories, Lovelock theories, or Lagrangians which in addition to higherorder curvature terms also include couplings to the matter sector. Another class of theories under our scrutiny will be generalized scalartensor or vectortensor gravity theories, where scalar or vector fields play gravitational roles that can also be perceived as couplings to matter in an appropriate frame. Additionally, another fundamental goal is to study the theoretical issues of the extra degrees of freedom of the theory and finally astrophysical applications, such as in black hole physics, in all of these classes of modified gravity will also be analyzed. References: [1] S. Perlmutter et al. [Supernova Cosmology Project Collaboration], Astrophys. J. 517, 565 (1999). [2] A.G. Riess et al. [Supernova Search Team Collaboration], Astron. J. 116, 1009 (1998). [3] R. Maartens, Living Rev. Rel. 7, 7 (2004). [4] G.R. Dvali, G. Gabadadze and M. Porrati, Phys. Lett. B 485, 208 (2000). [5] T.P. Sotiriou and V. Faraoni, Rev. Mod. Phys. 82, 451 (2010); [6] A. De Felice and S. Tsujikawa, Livinging Rev. Rel. 13, 3 (2010); [7] S. Capozziello and M. De Laurentis, Phys. Rept. 509, 167 (2011). [8] S. Nojiri and S.D. Odintsov, Phys. Rept. 505, 59 (2011). [9] S.M. Carroll, V. Duvvuri, M. Trodden and M.S. Turner, Phys. Rev. D 70, 043528 (2004). [10] A.B. Balakin, V.V. Bochkarev, J.P.S. Lemos, Phys. Rev. D 85, 064015 (2012). [11] L. Amendola et al. [Euclid Theory Working Group Collaboration], Living Rev. Rel. 16, 6 (2013). [12] C. de Rham, Living Rev. Rel. 17, 7 (2014). [13] G.W. Horndeski, Int. J. Theor. Phys., 10, 363 (1974). [14] M.S. Volkov, Class. Quant. Grav. 30, 184009 (2013). [15] T.P. Sotiriou and S. Liberati, Annals Phys. 322, 935 (2007). [16] R. Ferraro and F. Fiorini, Phys. Rev. D 75, 084031 (2007). [17] E.V. Linder, Phys. Rev. D 81, 127301 (2010). [18] T. Harko, F.S.N. Lobo, G. Otalora and E.N. Saridakis, Phys.Rev. D 89, 124036, (2014). [19] Y.F. Cai, S.H. Chen, J.B. Dent, S. Dutta and E.N. Saridakis, Class. Quant. Grav. 28, 215011 (2011). [20] H. van Dam, M. Veltman, Nucl. Phys. B22, 397 411 (1970); V. Zakharov, JETP Lett. 12, 312 (1970). [21] W. J. Percival, et al, Mon. Not. Roy. Astron. Soc. 381, 1053 (2007). [22] J. E. Lidsey et al, Rev. Mod. Phys. 69 373 (1997). [23] E.J. Copeland, M. Sami and S. Tsujikawa, Int. J. Mod. Phys. D 15, 1753 (2006).
Thesis Student

Student:
João Rosa

Status:
Concluded

Started At:
October 01, 2015

Ended At:
October 30, 2019