Glimpses Into the Early Universe

  title={Glimpses Into the Early Universe},
  author={David Langlois},
  journal={arXiv: High Energy Physics - Theory},
  • D. Langlois
  • Published 2 October 2009
  • Physics
  • arXiv: High Energy Physics - Theory
This contribution gives a brief overview of the theoretical ideas underlying our current understanding of the early Universe. Confronting the predictions of the early Universe models with cosmological observations, in particular of the cosmic microwave background fluctuations, will improve our knowledge about the physics of the primordial Universe. 



Inflation, Quantum Fluctuations and Cosmological Perturbations

These lectures are intended to give a pedagogical introduction to the main current picture of the very early universe. After elementary reviews of general relativity and of the standard Big Bang

Density fluctuations in Brans-Dicke inflation

Spectrum of density perturbations in the Universe generated from quantum-gravitational fluctuations in slow-roll-over inflationary scenarios with the Brans-Dicke gravity is calculated. It is shown

Primordial fluctuations and non-Gaussianities in multifield Dirac-Born-Infeld inflation.

It is shown that the adiabatic and entropy modes propagate with a common effective sound speed and are thus amplified at the sound horizon crossing and this could strongly affect the observable curvature power spectrum as well as the amplitude of non-Gaussianities, although their shape remains as in the single-field Dirac-Born-Infeld case.

Perturbations in generalized multi-field inflation

We study the linear perturbations of multi-field inflationary models governed by a Lagrangian which is a general function of the scalar fields and of a global kinetic term combining their spacetime

Primordial perturbations and non-Gaussianities in DBI and general multifield inflation

We study cosmological perturbations in general inflation models with multiple scalar fields and arbitrary kinetic terms, with special emphasis on the multifield extension of Dirac-Born-Infeld (DBI)

Scalar speed limits and cosmology: Acceleration from D-cceleration

Causality on the gravity side of the AdS/CFT correspondence restricts motion on the moduli space of the N = 4 super Yang Mills theory by imposing a speed limit on how fast the scalar field may roll.

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