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T: Fachverband Teilchenphysik

T 23: Theoretische Astroteilchenphysik und Kosmologie 2

T 23.2: Talk

Tuesday, March 10, 2009, 17:00–17:15, M114

Inflationary perturbation spectra from Lorentz violating dissipative models — •Julian Adamek¹, David Campo¹, Jens Niemeyer¹, and Renaud Parentani² — ¹ITPA Universität Würzburg, Würzburg, Germany — ²LPT CNRS Université Paris-Sud 11, Orsay Cedex, France

Trans-Planckian redshifts in cosmology and the question of initial conditions for primordial fluctuations are addressed in the context of a phenomenological model that breaks Lorentz invariance by dissipative effects above an energy scale Λ. These effects are dynamically obtained by coupling the fluctuation modes to additional degrees of freedom which are unobservable below Λ. When these degrees of freedom are in their ground state (vacuum), and when the Hubble rate H is much smaller than Λ (scale separation), the standard prediction for the spectral power remains robust. For a large class of dissipative models, using analytical and numerical methods, we show that the leading modification (in an expansion in H/Λ) is linear in the decay rate evaluated at horizon exit, and that high frequency superimposed oscillations are not generated. The modification is negative when the decay rate decreases slower than the cube of H, which means that there is a loss of power on the largest scales.