Rights statement: 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.
Final published version, 198 KB, PDF document
Available under license: CC BY
Final published version
Licence: CC BY
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Sub-Planckian two-field inflation consistent with the Lyth bound
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 - 2014/9
Y1 - 2014/9
N2 - The BICEP2 observation of a large tensor-to-scalar ratio, r = 0.20(-0.05)(+0.07), implies that the inflaton phi in single-field inflation models must satisfy phi similar to 10 M-Pl in order to produce sufficient inflation. This is a problem if interaction terms suppressed by the Planck scale impose a bound phi less than or similar to M-Pl. Here we consider whether it is possible to have successful sub-Planckian inflation in the case of two-field inflation. The trajectory in field space cannot be radial if the effective single-field inflaton is to satisfy the Lyth bound. By considering a complex field Phi, we show that a near circular but aperiodic modulation of a vertical bar Phi vertical bar(4) potential can reproduce the results of phi(2) chaotic inflation for n(s) and r while satisfying vertical bar Phi vertical bar less than or similar to 0.01 M-Pl throughout. More generally, for models based on a vertical bar Phi vertical bar(4) potential, the simplest sub-Planckian models are equivalent to phi(2) and phi(4/3) chaotic inflation.
AB - The BICEP2 observation of a large tensor-to-scalar ratio, r = 0.20(-0.05)(+0.07), implies that the inflaton phi in single-field inflation models must satisfy phi similar to 10 M-Pl in order to produce sufficient inflation. This is a problem if interaction terms suppressed by the Planck scale impose a bound phi less than or similar to M-Pl. Here we consider whether it is possible to have successful sub-Planckian inflation in the case of two-field inflation. The trajectory in field space cannot be radial if the effective single-field inflaton is to satisfy the Lyth bound. By considering a complex field Phi, we show that a near circular but aperiodic modulation of a vertical bar Phi vertical bar(4) potential can reproduce the results of phi(2) chaotic inflation for n(s) and r while satisfying vertical bar Phi vertical bar less than or similar to 0.01 M-Pl throughout. More generally, for models based on a vertical bar Phi vertical bar(4) potential, the simplest sub-Planckian models are equivalent to phi(2) and phi(4/3) chaotic inflation.
KW - inflation
KW - physics of the early universe
KW - BACKGROUND ANISOTROPY
U2 - 10.1088/1475-7516/2014/09/027
DO - 10.1088/1475-7516/2014/09/027
M3 - Journal article
VL - 2014
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 9
M1 - 027
ER -