Dark Radiation in LARGE Volume Models

Abstract

We consider reheating driven by volume modulus decays in the LARGE Volume Scenario. Such reheating always generates non-zero dark radiation through the decays to the axion partner, while the only competitive visible sector decays are Higgs pairs via the Giudice-Masiero term. In the framework of sequestered models where the cosmological moduli problem is absent, the simplest model with a shift-symmetric Higgs sector generates 1.56 < N_{eff} - N_{eff,SM} < 1.74. For more general cases, the known experimental bounds on N_{eff} strongly constrain the parameters and matter content of the models.

6 pages; v2. refs updated

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Cited by in corpus (8)

• Dark matter production in the early Universe: beyond the thermal WIMP paradigm
• Towards Axionic Starobinsky-like Inflation in String Theory
• Inflationary Constraints on Late Time Modulus Dominated Cosmology
• Relaxing Isocurvature Bounds on String Axion Dark Matter
• Exploring the Role of Axions and Other WISPs in the Dark Universe
• ALP Conversion and the Soft X-ray Excess in the Outskirts of the Coma Cluster
• The Darkness of Spin-0 Dark Radiation
• Non-thermal CMSSM with a 125 GeV Higgs