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TY - JOUR
T1 - A minimal sub-Planckian axion inflation model with large tensor-to-scalar ratio
AU - McDonald, John
N1 - Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
PY - 2015/1
Y1 - 2015/1
N2 - We present a minimal axion inflation model which can generate a large tensor-to-scalar ratio while remaining sub-Planckian. The modulus of a complex scalar field Phi with a lambda vertical bar Phi vertical bar(4) potential couples directly to the gauge field of a strongly-coupled sector via a term of the form (vertical bar Phi vertical bar/M-Pl)(m) F (F) over tilde . This generates a minimum of the potential which is aperiodic in the phase. The resulting inflation model is equivalent to a phi(4/(m+1)) chaotic inflation model. For the natural case of a leading-order portal-like interaction of the form Phi dagger Phi F (F) over tilde, the model is equivalent to a phi(4/3) chaotic inflation model and predicts a tensor-to-scalar ratio r = 16/3N = 0.097 and a scalar spectral index n(s) = 1 - 5/3N = 0.970 . The value of vertical bar Phi vertical bar remains sub-Planckian throughout the observable era of inflation, with vertical bar Phi vertical bar less than or similar to 0.01M(Pl) for N less than or similar to 60 when lambda similar to 1.
AB - We present a minimal axion inflation model which can generate a large tensor-to-scalar ratio while remaining sub-Planckian. The modulus of a complex scalar field Phi with a lambda vertical bar Phi vertical bar(4) potential couples directly to the gauge field of a strongly-coupled sector via a term of the form (vertical bar Phi vertical bar/M-Pl)(m) F (F) over tilde . This generates a minimum of the potential which is aperiodic in the phase. The resulting inflation model is equivalent to a phi(4/(m+1)) chaotic inflation model. For the natural case of a leading-order portal-like interaction of the form Phi dagger Phi F (F) over tilde, the model is equivalent to a phi(4/3) chaotic inflation model and predicts a tensor-to-scalar ratio r = 16/3N = 0.097 and a scalar spectral index n(s) = 1 - 5/3N = 0.970 . The value of vertical bar Phi vertical bar remains sub-Planckian throughout the observable era of inflation, with vertical bar Phi vertical bar less than or similar to 0.01M(Pl) for N less than or similar to 60 when lambda similar to 1.
KW - inflaiion
KW - physics of the early universe
KW - CHAOTIC INFLATION
KW - CP INVARIANCE
KW - SUPERGRAVITY
U2 - 10.1088/1475-7516/2015/01/018
DO - 10.1088/1475-7516/2015/01/018
M3 - Journal article
VL - 2015
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 1
M1 - 018
ER -