Cosmological Perturbations in Einstein-Aether Theories

• Autores: Noela Fariña Sierra
• Directores de la Tesis: Jaume Garriga Torres (dir. tes.)
• Lectura: En la Universitat de Barcelona ( España ) en 2011
• Idioma: inglés
• Tribunal Calificador de la Tesis: Enric Verdaguer Oms (presid.), Alessio Notari (secret.), Oriol Pujolàs Boix (voc.)
• Materias:
  • Astronomía y astrofísica
    • Cosmología y cosmogonía
      • Gravitación
  • Física
    • Física teórica
      • Gravitación
• Enlaces
  • Tesis en acceso abierto en:  TDX  Dipòsit Digital de la UB 
• Resumen

  • In this thesis we study the Einstein-Aether (E-A) theory from the point of view of its cosmological perturbations. We are interested in the constraints that may be obtained from this analysis and the special features that can arise from the vector mode, absent in General Relativity. We apply the theory of linear perturbations in an expanding universe to describe the growth of inhomogeneities on subhorizon scales after recombination. We can split the perturbations in the different modes (scalar, vector and tensor) and we can study each of them separately. This allow us to obtain the stability conditions for this kind of theories and we can also obtain the power spectrum for each mode. For the scalar modes, we calculate the subhorizon solutions during the radiation and matter domination epochs. We are also interested in the effect of the theory in the Cosmic Microwave Background anisotropies, in particular in the contribution of the vector modes, as these modes are absent in General Relativity. We analyze the solutions for radiation and matter and calculate the angular power spectrum at large and small angular scales. This allows us to compare the contribution of the vector modes with the one coming from the tensor ones and with observations. The last issue we address is the effects of the vector modes in the polarization of the Cosmic Microwave Background.