Abstract
Natural inflation relies on the existence of an axion decay constant which is super-Planckian. In string theory only sub-Planckian axion decay constants have been found in any controlled regime. However in field theory it is possible to generate an enhanced super-Planckian decay constant by an appropriate aligned mixing between axions with individual sub-Planckian decay constants. We study the possibility of such a mechanism in string theory. In particular we construct a new realisation of an alignment scenario in type IIA string theory compactifications on a Calabi-Yau where the alignment is induced through fluxes. Within field theory the original decay constants are taken to be independent of the parameters which induce the alignment. In string theory however they are moduli dependent quantities and so interact gravitationally with the physics responsible for the mixing. We show that this gravitational effect of the fluxes on the moduli can precisely cancel any enhancement of the effective decay constant. This censorship of an effective super-Planckian decay constant depends on detailed properties of Calabi-Yau moduli spaces and occurs for all the examples and classes that we study. We expand these results to a general superpotential assuming only that the axion superpartners are fixed supersymmetrically and are able to show for a large class of Calabi-Yau manifolds, but not all, that the cancellation effect occurs and is independent of the superpotential. We also study simple models where the moduli are fixed non-supersymmetrically and find that similar cancellation behaviour can emerge. Finally we make some comments on a possible generalisation to axion monodromy inflation models.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Planck collaboration, P.A.R. Ade et al., Planck 2015 results. XX. Constraints on inflation, arXiv:1502.02114 [INSPIRE].
K. Freese, J.A. Frieman and A.V. Olinto, Natural inflation with pseudo-Nambu-Goldstone bosons, Phys. Rev. Lett. 65 (1990) 3233 [INSPIRE].
X. Dong, B. Horn, E. Silverstein and A. Westphal, Simple exercises to flatten your potential, Phys. Rev. D 84 (2011) 026011 [arXiv:1011.4521] [INSPIRE].
L.E. Ibáñez, F. Marchesano and I. Valenzuela, Higgs-otic Inflation and String Theory, JHEP 01 (2015) 128 [arXiv:1411.5380] [INSPIRE].
W. Buchmüller, E. Dudas, L. Heurtier, A. Westphal, C. Wieck and M.W. Winkler, Challenges for Large-Field Inflation and Moduli Stabilization, JHEP 04 (2015) 058 [arXiv:1501.05812] [INSPIRE].
E. Dudas and C. Wieck, Moduli backreaction and supersymmetry breaking in string-inspired inflation models, JHEP 10 (2015) 062 [arXiv:1506.01253] [INSPIRE].
R. Kappl, H.P. Nilles and M.W. Winkler, Natural Inflation and Low Energy Supersymmetry, Phys. Lett. B 746 (2015) 15 [arXiv:1503.01777] [INSPIRE].
M. Peloso and C. Unal, Trajectories with suppressed tensor-to-scalar ratio in Aligned Natural Inflation, JCAP 06 (2015) 040 [arXiv:1504.02784] [INSPIRE].
J.E. Kim, H.P. Nilles and M. Peloso, Completing natural inflation, JCAP 01 (2005) 005 [hep-ph/0409138] [INSPIRE].
T. Banks, M. Dine, P.J. Fox and E. Gorbatov, On the possibility of large axion decay constants, JCAP 06 (2003) 001 [hep-th/0303252] [INSPIRE].
P. Svrček and E. Witten, Axions In String Theory, JHEP 06 (2006) 051 [hep-th/0605206] [INSPIRE].
Z. Kenton and S. Thomas, D-brane Potentials in the Warped Resolved Conifold and Natural Inflation, JHEP 02 (2015) 127 [arXiv:1409.1221] [INSPIRE].
N. Arkani-Hamed, L. Motl, A. Nicolis and C. Vafa, The String landscape, black holes and gravity as the weakest force, JHEP 06 (2007) 060 [hep-th/0601001] [INSPIRE].
C. Cheung and G.N. Remmen, Naturalness and the Weak Gravity Conjecture, Phys. Rev. Lett. 113 (2014) 051601 [arXiv:1402.2287] [INSPIRE].
T. Rudelius, Constraints on Axion Inflation from the Weak Gravity Conjecture, JCAP 09 (2015) 020 [arXiv:1503.00795] [INSPIRE].
J. Brown, W. Cottrell, G. Shiu and P. Soler, Fencing in the Swampland: Quantum Gravity Constraints on Large Field Inflation, JHEP 10 (2015) 023 [arXiv:1503.04783] [INSPIRE].
M. Montero, A.M. Uranga and I. Valenzuela, Transplanckian axions!?, JHEP 08 (2015) 032 [arXiv:1503.03886] [INSPIRE].
A. Hebecker, P. Mangat, F. Rompineve and L.T. Witkowski, Winding out of the Swamp: Evading the Weak Gravity Conjecture with F-term Winding Inflation?, Phys. Lett. B 748 (2015) 455 [arXiv:1503.07912] [INSPIRE].
J. Brown, W. Cottrell, G. Shiu and P. Soler, On Axionic Field Ranges, Loopholes and the Weak Gravity Conjecture, arXiv:1504.00659 [INSPIRE].
B. Heidenreich, M. Reece and T. Rudelius, Weak Gravity Strongly Constrains Large-Field Axion Inflation, arXiv:1506.03447 [INSPIRE].
D. Junghans, Large-Field Inflation with Multiple Axions and the Weak Gravity Conjecture, arXiv:1504.03566 [INSPIRE].
O. DeWolfe, A. Giryavets, S. Kachru and W. Taylor, Type IIA moduli stabilization, JHEP 07 (2005) 066 [hep-th/0505160] [INSPIRE].
T.W. Grimm and J. Louis, The Effective action of type IIA Calabi-Yau orientifolds, Nucl. Phys. B 718 (2005) 153 [hep-th/0412277] [INSPIRE].
E. Palti, G. Tasinato and J. Ward, WEAKLY-coupled IIA Flux Compactifications, JHEP 06 (2008) 084 [arXiv:0804.1248] [INSPIRE].
F. Denef, M.R. Douglas and B. Florea, Building a better racetrack, JHEP 06 (2004) 034 [hep-th/0404257] [INSPIRE].
B.S. Acharya, F. Benini and R. Valandro, Fixing moduli in exact type IIA flux vacua, JHEP 02 (2007) 018 [hep-th/0607223] [INSPIRE].
R. Blumenhagen, M. Cvetič, S. Kachru and T. Weigand, D-Brane Instantons in Type II Orientifolds, Ann. Rev. Nucl. Part. Sci. 59 (2009) 269 [arXiv:0902.3251] [INSPIRE].
P.G. Camara, A. Font and L.E. Ibáñez, Fluxes, moduli fixing and MSSM-like vacua in a simple IIA orientifold, JHEP 09 (2005) 013 [hep-th/0506066] [INSPIRE].
H. Ooguri and C. Vafa, Summing up D instantons, Phys. Rev. Lett. 77 (1996) 3296 [hep-th/9608079] [INSPIRE].
L.B. Anderson, J. Gray, A. Lukas and B. Ovrut, Stabilizing All Geometric Moduli in Heterotic Calabi-Yau Vacua, Phys. Rev. D 83 (2011) 106011 [arXiv:1102.0011] [INSPIRE].
D. Baumann and L. McAllister, Inflation and String Theory, arXiv:1404.2601 [INSPIRE].
C. Long, L. McAllister and P. McGuirk, Aligned Natural Inflation in String Theory, Phys. Rev. D 90 (2014) 023501 [arXiv:1404.7852] [INSPIRE].
I. Ben-Dayan, F.G. Pedro and A. Westphal, Towards Natural Inflation in String Theory, Phys. Rev. D 92 (2015) 023515 [arXiv:1407.2562] [INSPIRE].
F. Ruehle and C. Wieck, Natural inflation and moduli stabilization in heterotic orbifolds, JHEP 05 (2015) 112 [arXiv:1503.07183] [INSPIRE].
X. Gao, T. Li and P. Shukla, Combining Universal and Odd RR Axions for Aligned Natural Inflation, JCAP 10 (2014) 048 [arXiv:1406.0341] [INSPIRE].
P. Candelas, X. De La Ossa, A. Font, S.H. Katz and D.R. Morrison, Mirror symmetry for two parameter models. 1., Nucl. Phys. B 416 (1994) 481 [hep-th/9308083] [INSPIRE].
M. Cicoli, M. Kreuzer and C. Mayrhofer, Toric K3-Fibred Calabi-Yau Manifolds with del Pezzo Divisors for String Compactifications, JHEP 02 (2012) 002 [arXiv:1107.0383] [INSPIRE].
R. Blumenhagen, D. Herschmann and E. Plauschinn, The Challenge of Realizing F-term Axion Monodromy Inflation in String Theory, JHEP 01 (2015) 007 [arXiv:1409.7075] [INSPIRE].
A. Hebecker, P. Mangat, F. Rompineve and L.T. Witkowski, Tuning and Backreaction in F-term Axion Monodromy Inflation, Nucl. Phys. B 894 (2015) 456 [arXiv:1411.2032] [INSPIRE].
R. Blumenhagen et al., A Flux-Scaling Scenario for High-Scale Moduli Stabilization in String Theory, Nucl. Phys. B 897 (2015) 500 [arXiv:1503.07634] [INSPIRE].
G. Shiu, W. Staessens and F. Ye, Widening the Axion Window via Kinetic and Stückelberg Mixings, arXiv:1503.01015 [INSPIRE].
G. Shiu, W. Staessens and F. Ye, Large Field Inflation from Axion Mixing, JHEP 06 (2015) 026 [arXiv:1503.02965] [INSPIRE].
S. Dimopoulos, S. Kachru, J. McGreevy and J.G. Wacker, N-flation, JCAP 08 (2008) 003 [hep-th/0507205] [INSPIRE].
T.C. Bachlechner, C. Long and L. McAllister, Planckian Axions and the Weak Gravity Conjecture, arXiv:1503.07853 [INSPIRE].
T.C. Bachlechner, C. Long and L. McAllister, Planckian Axions in String Theory, arXiv:1412.1093 [INSPIRE].
T.C. Bachlechner, M. Dias, J. Frazer and L. McAllister, Chaotic inflation with kinetic alignment of axion fields, Phys. Rev. D 91 (2015) 023520 [arXiv:1404.7496] [INSPIRE].
M.P. Hertzberg, S. Kachru, W. Taylor and M. Tegmark, Inflationary Constraints on Type IIA String Theory, JHEP 12 (2007) 095 [arXiv:0711.2512] [INSPIRE].
A. Hebecker, E. Palti and L.T. Witkowski, work in progress.
E. Silverstein and A. Westphal, Monodromy in the CMB: Gravity Waves and String Inflation, Phys. Rev. D 78 (2008) 106003 [arXiv:0803.3085] [INSPIRE].
F. Marchesano, G. Shiu and A.M. Uranga, F-term Axion Monodromy Inflation, JHEP 09 (2014) 184 [arXiv:1404.3040] [INSPIRE].
A. Hebecker, S.C. Kraus and L.T. Witkowski, D7-Brane Chaotic Inflation, Phys. Lett. B 737 (2014) 16 [arXiv:1404.3711] [INSPIRE].
R. Blumenhagen and E. Plauschinn, Towards Universal Axion Inflation and Reheating in String Theory, Phys. Lett. B 736 (2014) 482 [arXiv:1404.3542] [INSPIRE].
R. Blumenhagen, A. Font, M. Fuchs, D. Herschmann and E. Plauschinn, Towards Axionic Starobinsky-like Inflation in String Theory, Phys. Lett. B 746 (2015) 217 [arXiv:1503.01607] [INSPIRE].
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1508.00009
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Palti, E. On natural inflation and moduli stabilisation in string theory. J. High Energ. Phys. 2015, 188 (2015). https://doi.org/10.1007/JHEP10(2015)188
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP10(2015)188