Dynamical chaotic inflation in the light of BICEP2

The measurement of a large tensor-to-scalar ratio by the BICEP2 experiment, <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>r</mi><mo>=</mo><msubsup><mrow><mn>0.20</mn></mrow><mrow><mo>−</mo><mn>0.05</mn></mrow><mrow><mo>+</mo><mn>0.07</mn></mrow></msubsup></math> , severely restricts the landscape of viable inflationary models and shifts attention once more towards models featuring large inflaton field values. In this context, chaotic inflation based on a fractional power-law potential that is dynamically generated by the dynamics of a strongly coupled supersymmetric gauge theory appears to be particularly attractive. We revisit this class of inflation models and find that, in the light of the BICEP2 measurement, models with a non-minimal gauge group behind the dynamical model seem to be disfavored, while the model with the simplest group, i.e. <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="italic">SU</mi></mrow><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></math> , is consistent with all results. We also discuss how the dynamical model can be distinguished from the standard chaotic inflation model based on a quadratic inflaton potential