Generating primordial features at large scales in two field models of inflation. (arXiv:2004.00672v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Braglia_M/0/1/0/all/0/1">Matteo Braglia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hazra_D/0/1/0/all/0/1">Dhiraj Kumar Hazra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sriramkumar_L/0/1/0/all/0/1">Lakshmanan Sriramkumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Finelli_F/0/1/0/all/0/1">Fabio Finelli</a>
We investigate the generation of features at large scales in the primordial
power spectrum (PPS) when inflation is driven by two scalar fields. In
canonical single field models of inflation, these features are often generated
due to deviations from the slow-roll regime. While deviations from slow-roll
can be naturally achieved in two field models due to a sharp turn in the
trajectory in the field space, features at the largest scales of the types
suggested by CMB temperature anisotropies are more difficult to achieve in
models involving two canonical scalar fields due to the presence of
isocurvature fluctuations. We show instead that a coupling between the kinetic
terms of the scalar fields can easily produce such features. We discuss models
whose theoretical predictions are consistent with current observations and
highlight the implications of our results.
We investigate the generation of features at large scales in the primordial
power spectrum (PPS) when inflation is driven by two scalar fields. In
canonical single field models of inflation, these features are often generated
due to deviations from the slow-roll regime. While deviations from slow-roll
can be naturally achieved in two field models due to a sharp turn in the
trajectory in the field space, features at the largest scales of the types
suggested by CMB temperature anisotropies are more difficult to achieve in
models involving two canonical scalar fields due to the presence of
isocurvature fluctuations. We show instead that a coupling between the kinetic
terms of the scalar fields can easily produce such features. We discuss models
whose theoretical predictions are consistent with current observations and
highlight the implications of our results.
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