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arXiv · 1708.01709

On the Effective Field Theory for Quasi-Single Field Inflation

Xi Tong·Yi Wang·Siyi Zhou
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Abstract

We study the effective field theory (EFT) description of the virtual particle effects in quasi-single field inflation, which unifies the previous results on large mass and large mixing cases. By using a horizon crossing approximation and matching with known limits, approximate expressions for the power spectrum and the spectral index are obtained. The error of the approximate solution is within 10% in dominate parts of the parameter space, which corresponds to less-than-0.1% error in the $n_s$-$r$ diagram. The quasi-single field corrections on the $n_s$-$r$ diagram are plotted for a few inflation models. Especially, the quasi-single field correction drives $m^2\phi^2$ inflation to the best fit region on the $n_s$-$r$ diagram, with an amount of equilateral non-Gaussianity which can be tested in future experiments.

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Xi Tong, Yi Wang, Siyi Zhou. 2017-08-05. On the Effective Field Theory for Quasi-Single Field Inflation. https://doi.org/10.1088/1475-7516%2F2017%2F11%2F045

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