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Parametric resonance with Multi-frequencies in preheating

Study of inflaton field decay to scalar field χ in parametric resonance preheating with multiple couplings and resonance regions. Exploring energy transfer efficiency and cosmological implications.

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Parametric resonance with Multi-frequencies in preheating

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  1. Parametric resonance with Multi-frequencies in preheating José Pedro Mimoso Physics Dep. Science Fac. & CFTC University of Lisboa Collaboration with: Ana Nunes Tiago Charters arXiv: 0807.4805v1 [hep-ph] ERE08 –Salamanca: September 15, 2008

  2. Abstract We study the decay of the inflaton field to another scalar field χ in the parametric resonance preheating mechanism.We consider the presence of several simultaneous couplings between the fields.This amounts to the existence of extra harmonic terms in the perturbation of the χ field dynamics. For the case of two frequencies we compute the geometry of the resonance regions, which is significantly altered due to the presence of non-cuspidal resonance regions associated to higher harmonics and to the emergence of instability `pockets'.We discuss the effect of this change in the efficiency of the energy transfer process for the simplest non-homogeneous coupling. We find that the presence of a finite number of higher harmonics has limited cosmological implications.

  3. Outline: Motivations (P)reheating after Inflation Preheating with multi-frequencies Conclusions ERE08 –Salamanca: September 15, 2008

  4. Inflation: as much of a problem as of a solution?! V(Φ) Slow roll Fast oscillations Φ Inflation exhausts the Universe: The accelerated expansion dilutes the matter content Trad~ e-60 Tinit The universe becomes too cold ERE08 –Salamanca: September 15, 2008

  5. So First, inflation Second, recreate Hell (A. Linde) ERE08 –Salamanca: September 15, 2008

  6. Coherent oscillations of [Chaotic inflation - A. Linde] [M. S. Turner, 1983] The expansion of the universe can be neglected ERE08 –Salamanca: September 15, 2008

  7. Old Reheating “Old” reheating Phenomenological perturbative decay of the inflaton Temperature reheating Thermalization ERE08 –Salamanca: September 15, 2008

  8. “New” Reheating Inflaton – homogeneous field –> large occupation of k=0 mode Φ~ Classical field acting on quantum fields χ, ψ Makes masses of χ, ψ to vary periodically Preheating Parametric Resonance of Thermalization ERE08 –Salamanca: September 15, 2008

  9. Parametric Resonance Exponential Production of Particles Periodic Floquet theor. Ignore expansion Minkowski Mathieu Equation Broad Resonance Distinguish Narrow Resonance ERE08 –Salamanca: September 15, 2008

  10. Broad Resonance Narrow Resonance ERE08 –Salamanca: September 15, 2008

  11. Broad Resonance Narrow Resonance ERE08 –Salamanca: September 15, 2008

  12. Narrow Resonance ICG –Portsmouth: May 16, 2008

  13. Narrow Resonance ERE08 –Salamanca: September 15, 2008

  14. ERE08 –Salamanca: September 15, 2008

  15. Narrow resonance ERE08 –Salamanca: September 15, 2008

  16. ERE08 –Salamanca: September 15, 2008

  17. ERE08 –Salamanca: September 15, 2008

  18. ERE08 –Salamanca: September 15, 2008

  19. arXiv: 0807.4805v1 [hep-ph] [Dufaux et al, PRD (2006) hep-ph/0602144v2 Tachyonic Resonance] ERE08 –Salamanca: September 15, 2008

  20. ERE08 –Salamanca: September 15, 2008

  21. Expanding Universe There is particle production if the frequency does not redshift out of the resonance band in a time interval shorter than the amplification period ERE08 –Salamanca: September 15, 2008

  22. The reason are that in the second resonance band the values of μ are shifted up and are smaller for the same peturbation amplitude L is much smaller. Moreover the distortion created by the emergence of the instability pocket narrows the instability band as the perturbation amplitude is increased… Differs very little from the contribution coming from the first band. ERE08 –Salamanca: September 15, 2008

  23. Conclusion The assumption that the particle production in the narrow resonance regime is only due to the first instability band is justified and so are the conclusions regarding the lesser effectiveness of this regime to contribute to the particle production and reheating. THANKS FOR LISTENING! ERE08 –Salamanca: September 15, 2008

  24. ERE08 –Salamanca: September 15, 2008

  25. Broad Resonance [Kofman, Linde and Starobinski, Phys. Rev. D 56 (1997) 3258-3295 ] ERE08 –Salamanca: September 15, 2008

  26. ERE08 –Salamanca: September 15, 2008

  27. Kofman, Linde and Starobinski, Phys. Rev. D 56 (1997) 3258-3295 ERE08 –Salamanca: September 15, 2008

  28. Charters, Mimoso & Nunes ERE08 –Salamanca: September 15, 2008

  29. ERE08 –Salamanca: September 15, 2008

  30. ERE08 –Salamanca: September 15, 2008

  31. ERE08 –Salamanca: September 15, 2008

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  33. ERE08 –Salamanca: September 15, 2008

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