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arXiv · 1901.06097

Anisotropic inflation with coupled $\boldsymbol{p}$-forms

Juan P. Beltrán Almeida·Alejandro Guarnizo·Ryotaro Kase·Shinji Tsujikawa·César A. Valenzuela-Toledo
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Abstract

We study the cosmology in the presence of arbitrary couplings between $p$-forms in 4-dimensional space-time for a general action respecting gauge symmetry and parity invariance. The interaction between 0-form (scalar field $ϕ$) and 3-form fields gives rise to an effective potential $V_{\rm eff}(ϕ)$ for the former after integrating out the contribution of the latter. We explore the dynamics of inflation on an anisotropic cosmological background for a coupled system of 0-, 1-, and 2-forms. In the absence of interactions between 1- and 2-forms, we derive conditions under which the anisotropic shear endowed with nearly constant energy densities of 1- and 2-forms survives during slow-roll inflation for an arbitrary scalar potential $V_{\rm eff}(ϕ)$. If 1- and 2-forms are coupled to each other, we show the existence of a new class of anisotropic inflationary solutions in which the energy density of 2-form is sustained by that of 1-form through their interactions. Our general analytic formulas for the anisotropic shear are also confirmed by the numerical analysis for a concrete inflaton potential.

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Juan P. Beltrán Almeida, Alejandro Guarnizo, Ryotaro Kase, Shinji Tsujikawa, César A. Valenzuela-Toledo. 2019-03-06. Anisotropic inflation with coupled $\boldsymbol{p}$-forms. https://doi.org/10.1088/1475-7516%2F2019%2F03%2F025

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