TY - JOUR

T1 - Isocurvature perturbations of dark energy and dark matter from the Swampland conjecture

AU - Matsui, Hiroki

AU - Takahashi, Fuminobu

AU - Yamada, Masaki

N1 - Funding Information:
F.T. thanks Mohammad Hossein Namjoo and Alan H. Guth for useful discussion. F.T. thanks the hospitality of MIT Center for Theoretical Physics and Tufts Institute of Cosmology where the present work was done. This work is partially supported by JSPS KAKENHI Grant Numbers JP15H05889 (F.T.), JP15K21733 (F.T.), JP17H02878 (F.T.), and JP17H02875 (H.M. and F.T.), Leading Young Researcher Overseas Visit Program at Tohoku University (F.T.), and by World Premier International Research Center Initiative (WPI Initiative), MEXT , Japan (F.T.).
Publisher Copyright:
© 2018 The Author(s)

PY - 2019/2/10

Y1 - 2019/2/10

N2 - We point out that the recently proposed Swampland conjecture on the potential gradient can lead to isocurvature perturbations of dark energy, if the quintessence field acquires large quantum fluctuations during high-scale inflation preferred by the conjecture. Also, if the quintessence field is coupled to a dark sector that contains dark matter, isocurvature perturbation of dark matter is similarly induced. Both isocurvature perturbations can be suppressed if the quintessence potential allows a tracker solution in the early Universe. We find that a vector field of mass ≲ O(1) meV is an excellent dark matter candidate in this context, not only because the right abundance is known to be produced by quantum fluctuations during high-scale inflation without running afoul of isocurvature bounds, but also because its coupling to the quintessence does not spoil the flatness of the potential.

AB - We point out that the recently proposed Swampland conjecture on the potential gradient can lead to isocurvature perturbations of dark energy, if the quintessence field acquires large quantum fluctuations during high-scale inflation preferred by the conjecture. Also, if the quintessence field is coupled to a dark sector that contains dark matter, isocurvature perturbation of dark matter is similarly induced. Both isocurvature perturbations can be suppressed if the quintessence potential allows a tracker solution in the early Universe. We find that a vector field of mass ≲ O(1) meV is an excellent dark matter candidate in this context, not only because the right abundance is known to be produced by quantum fluctuations during high-scale inflation without running afoul of isocurvature bounds, but also because its coupling to the quintessence does not spoil the flatness of the potential.

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U2 - 10.1016/j.physletb.2018.12.055

DO - 10.1016/j.physletb.2018.12.055

M3 - Article

AN - SCOPUS:85059353620

SN - 0370-2693

VL - 789

SP - 387

EP - 392

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

ER -