|Author||Nitti, F. ♦ Porrati, M. ♦ Rombouts, J. -W|
|Date of Submission||2005-03-31|
|Subject Domain (in DDC)||Computer science, information & general works ♦ Natural sciences & mathematics ♦ Astronomy & allied sciences ♦ Physics|
|Subject Keyword||High Energy Physics - Theory ♦ Astrophysics ♦ General Relativity and Quantum Cosmology ♦ physics:astro-ph ♦ physics:gr-qc ♦ physics:hep-th|
|Abstract||We propose a novel approach to the problem of constraining cosmological initial conditions. Within the framework of effective field theory, we classify initial conditions in terms of boundary terms added to the effective action describing the cosmological evolution below Planckian energies. These boundary terms can be thought of as spacelike branes which may support extra instantaneous degrees of freedom and extra operators. Interactions and renormalization of these boundary terms allow us to apply to the boundary terms the field-theoretical requirement of naturalness, i.e. stability under radiative corrections. We apply this requirement to slow-roll inflation with non-adiabatic initial conditions, and to cyclic cosmology. This allows us to define in a precise sense when some of these models are fine-tuned. We also describe how to parametrize in a model-independent way non-Gaussian initial conditions; we show that in some cases they are both potentially observable and pass our naturalness requirement.|
|Description||Reference: Phys.Rev. D72 (2005) 063503|
|Learning Resource Type||Article|
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