Abstract
We propose a technically natural scenario whereby an initially large cosmological constant (c.c.) is relaxed down to the observed value due to the dynamics of a scalar evolving on a very shallow potential. The model crucially relies on a sector that violates the null energy condition (NEC) and gets activated only when the Hubble rate becomes sufficiently small — of the order of the present one. As a result of NEC violation, this low-energy universe evolves into inflation, followed by reheating and the standard Big Bang cosmology. The symmetries of the theory force the c.c. to be the same before and after the NEC-violating phase, so that a late-time observer sees an effective c.c. of the correct magnitude. Importantly, our model allows neither for eternal inflation nor for a set of possible values of dark energy, the latter fixed by the parameters of the theory.
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References
S. Weinberg, The Cosmological Constant Problem, Rev. Mod. Phys. 61 (1989) 1 [INSPIRE].
L.F. Abbott, A Mechanism for Reducing the Value of the Cosmological Constant, Phys. Lett. B 150 (1985) 427 [INSPIRE].
P.W. Graham, D.E. Kaplan and S. Rajendran, Cosmological Relaxation of the Electroweak Scale, Phys. Rev. Lett. 115 (2015) 221801 [arXiv:1504.07551] [INSPIRE].
G. Dvali and A. Vilenkin, Cosmic attractors and gauge hierarchy, Phys. Rev. D 70 (2004) 063501 [hep-th/0304043] [INSPIRE].
G. Dvali, Large hierarchies from attractor vacua, Phys. Rev. D 74 (2006) 025018 [hep-th/0410286] [INSPIRE].
N. Arkani-Hamed, H.-C. Cheng, M.A. Luty and S. Mukohyama, Ghost condensation and a consistent infrared modification of gravity, JHEP 05 (2004) 074 [hep-th/0312099] [INSPIRE].
P.J. Steinhardt and N. Turok, Why the cosmological constant is small and positive, Science 312 (2006) 1180 [astro-ph/0605173] [INSPIRE].
A.D. Linde, Hybrid inflation, Phys. Rev. D 49 (1994) 748 [astro-ph/9307002] [INSPIRE].
G. Gabadadze, The Big Constant Out, The Small Constant In, Phys. Lett. B 739 (2014) 263 [arXiv:1406.6701] [INSPIRE].
G. Gabadadze and S. Yu, Metamorphosis of the Cosmological Constant and 5D Origin of the Fiducial Metric, arXiv:1510.07943 [INSPIRE].
N. Kaloper, A. Padilla, D. Stefanyszyn and G. Zahariade, Manifestly Local Theory of Vacuum Energy Sequestering, Phys. Rev. Lett. 116 (2016) 051302 [arXiv:1505.01492] [INSPIRE].
N. Arkani-Hamed, S. Dimopoulos, G. Dvali and G. Gabadadze, Nonlocal modification of gravity and the cosmological constant problem, hep-th/0209227 [INSPIRE].
G. Dvali, S. Hofmann and J. Khoury, Degravitation of the cosmological constant and graviton width, Phys. Rev. D 76 (2007) 084006 [hep-th/0703027] [INSPIRE].
C. de Rham, G. Gabadadze, L. Heisenberg and D. Pirtskhalava, Cosmic Acceleration and the Helicity-0 Graviton, Phys. Rev. D 83 (2011) 103516 [arXiv:1010.1780] [INSPIRE].
C. Armendariz-Picon, T. Damour and V.F. Mukhanov, k-inflation, Phys. Lett. B 458 (1999) 209 [hep-th/9904075] [INSPIRE].
N. Arkani-Hamed, P. Creminelli, S. Mukohyama and M. Zaldarriaga, Ghost inflation, JCAP 04 (2004) 001 [hep-th/0312100] [INSPIRE].
T. Kobayashi, M. Yamaguchi and J. Yokoyama, G-inflation: Inflation driven by the Galileon field, Phys. Rev. Lett. 105 (2010) 231302 [arXiv:1008.0603] [INSPIRE].
M. Kawasaki, K. Kohri and N. Sugiyama, MeV scale reheating temperature and thermalization of neutrino background, Phys. Rev. D 62 (2000) 023506 [astro-ph/0002127] [INSPIRE].
S. Hannestad, What is the lowest possible reheating temperature?, Phys. Rev. D 70 (2004) 043506 [astro-ph/0403291] [INSPIRE].
É. Aubourg et al., Cosmological implications of baryon acoustic oscillation measurements, Phys. Rev. D 92 (2015) 123516 [arXiv:1411.1074] [INSPIRE].
W.E. East, M. Kleban, A. Linde and L. Senatore, Beginning inflation in an inhomogeneous universe, JCAP 09 (2016) 010 [arXiv:1511.05143] [INSPIRE].
P. Creminelli, M.A. Luty, A. Nicolis and L. Senatore, Starting the Universe: Stable Violation of the Null Energy Condition and Non-standard Cosmologies, JHEP 12 (2006) 080 [hep-th/0606090] [INSPIRE].
S.D.H. Hsu, A. Jenkins and M.B. Wise, Gradient instability for ω < −1, Phys. Lett. B 597 (2004) 270 [astro-ph/0406043] [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].
D. Pirtskhalava, L. Santoni, E. Trincherini and P. Uttayarat, Inflation from Minkowski Space, JHEP 12 (2014) 151 [arXiv:1410.0882] [INSPIRE].
D. Pirtskhalava, L. Santoni, E. Trincherini and F. Vernizzi, Weakly Broken Galileon Symmetry, JCAP 09 (2015) 007 [arXiv:1505.00007] [INSPIRE].
A.A. Starobinsky, Spectrum of relict gravitational radiation and the early state of the universe, JETP Lett. 30 (1979) 682 [INSPIRE].
B. Whitt, Fourth Order Gravity as General Relativity Plus Matter, Phys. Lett. B 145 (1984) 176 [INSPIRE].
V.F. Mukhanov, H.A. Feldman and R.H. Brandenberger, Theory of cosmological perturbations. Part 1. Classical perturbations. Part 2. Quantum theory of perturbations. Part 3. Extensions, Phys. Rept. 215 (1992) 203 [INSPIRE].
L. Kofman, A.D. Linde and A.A. Starobinsky, Towards the theory of reheating after inflation, Phys. Rev. D 56 (1997) 3258 [hep-ph/9704452] [INSPIRE].
B.A. Bassett, S. Tsujikawa and D. Wands, Inflation dynamics and reheating, Rev. Mod. Phys. 78 (2006) 537 [astro-ph/0507632] [INSPIRE].
M.M. Ivanov and S. Sibiryakov, UV-extending Ghost Inflation, JCAP 05 (2014) 045 [arXiv:1402.4964] [INSPIRE].
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Alberte, L., Creminelli, P., Khmelnitsky, A. et al. Relaxing the cosmological constant: a proof of concept. J. High Energ. Phys. 2016, 22 (2016). https://doi.org/10.1007/JHEP12(2016)022
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DOI: https://doi.org/10.1007/JHEP12(2016)022