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arXiv · 1604.06520

Gravitational Leptogenesis in the Axion Inflation with an SU(2) gauge field

Azadeh Maleknejad
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Abstract

We present an intrinsic leptogenesis mechanism in models of axion inflation with a classical SU(2) gauge field. The gauge field is coupled to the axion with a Chern-Simons interaction and comprises a tiny fraction of the total energy, $\frac{\rho_{_{\rm YM}}}{\rho_{_{\rm tot}}}\lesssim\epsilon^2$. However, it has spin-2 fluctuations which breaks the parity and leads to the generation of chiral gravitational waves during inflation. By the gravitational anomaly in SM, it naturally creates a net lepton number density, sufficient to explain the matter asymmetry. We show that this mechanism can generate the observed value of baryon to photon number density in a natural range of parameters and yet has a small chiral tensor power spectrum on large scales.

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Azadeh Maleknejad. 2016-04-22. Gravitational Leptogenesis in the Axion Inflation with an SU(2) gauge field. https://doi.org/10.1088/1475-7516%2F2016%2F12%2F027

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