TY - JOUR
T1 - Natural inflation on a steep potential with classical non-Abelian gauge fields
AU - Adshead, Peter
AU - Wyman, Mark
PY - 2012/6/27
Y1 - 2012/6/27
N2 - We propose a model for inflation consisting of an axionic scalar field coupled to a set of three non-Abelian gauge fields. Our model's novel requirement is that the gauge fields begin inflation with a rotationally invariant vacuum expectation value (VEV) that is preserved through identification of SU(2) gauge invariance with rotations in three dimensions. The gauge VEV interacts with the background value of the axion, leading to an attractor solution that exhibits slow roll inflation even when the axion decay constant has a natural value (Pl). Assuming a sinusoidal potential for the axion, we find that inflation continues until the axionic potential vanishes. The speed at which the axion moves along its potential is modulated by its interactions with the gauge VEV, rather than being determined by the slope of its bare potential. For sub-Planckian axion decay constants vanishingly small tensor to scalar ratios are predicted, a direct consequence of the Lyth bound. The parameter that controls the interaction strength between the axion and the gauge fields requires a technically natural tuning of O(100).
AB - We propose a model for inflation consisting of an axionic scalar field coupled to a set of three non-Abelian gauge fields. Our model's novel requirement is that the gauge fields begin inflation with a rotationally invariant vacuum expectation value (VEV) that is preserved through identification of SU(2) gauge invariance with rotations in three dimensions. The gauge VEV interacts with the background value of the axion, leading to an attractor solution that exhibits slow roll inflation even when the axion decay constant has a natural value (Pl). Assuming a sinusoidal potential for the axion, we find that inflation continues until the axionic potential vanishes. The speed at which the axion moves along its potential is modulated by its interactions with the gauge VEV, rather than being determined by the slope of its bare potential. For sub-Planckian axion decay constants vanishingly small tensor to scalar ratios are predicted, a direct consequence of the Lyth bound. The parameter that controls the interaction strength between the axion and the gauge fields requires a technically natural tuning of O(100).
UR - http://www.scopus.com/inward/record.url?scp=84862980322&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84862980322&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.108.261302
DO - 10.1103/PhysRevLett.108.261302
M3 - Article
C2 - 23004957
AN - SCOPUS:84862980322
SN - 0031-9007
VL - 108
JO - Physical review letters
JF - Physical review letters
IS - 26
M1 - 261302
ER -