TY - JOUR

T1 - On the cosmological implications of the string Swampland

AU - Agrawal, Prateek

AU - Obied, Georges

AU - Steinhardt, Paul J.

AU - Vafa, Cumrun

N1 - Funding Information:
We would like to thank R. Daly, A. Ijjas, H. Ooguri, L. Spodyneiko and C. Stubbs for valuable discussions. PA would like to thank the Kavli Institute for Theoretical Physics for their hospitality during the completion of this work. The work of PA is supported by the NSF grants PHY-0855591 and PHY-1216270 . PJS thanks the NYU Center for Cosmology and Particle Physics and the Simons Foundation Origins of the Universe Initiative 548512 for support during his leave at NYU. PJS is supported by the DOE grant number DEFG02-91ER40671 . The work of CV is supported in part by NSF grant PHY-1067976 .
Funding Information:
We would like to thank R. Daly, A. Ijjas, H. Ooguri, L. Spodyneiko and C. Stubbs for valuable discussions. PA would like to thank the Kavli Institute for Theoretical Physics for their hospitality during the completion of this work. The work of PA is supported by the NSF grants PHY-0855591 and PHY-1216270. PJS thanks the NYU Center for Cosmology and Particle Physics and the Simons Foundation Origins of the Universe Initiative 548512 for support during his leave at NYU. PJS is supported by the DOE grant number DEFG02-91ER40671. The work of CV is supported in part by NSF grant PHY-1067976.
Publisher Copyright:
© 2018 The Author(s)

PY - 2018/9/10

Y1 - 2018/9/10

N2 - We study constraints imposed by two proposed string Swampland criteria on cosmology. These criteria involve an upper bound on the range traversed by scalar fields as well as a lower bound on |∇ϕV|/V when V>0. We find that inflationary models are generically in tension with these two criteria. Applying these same criteria to dark energy in the present epoch, we find that specific quintessence models can satisfy these bounds and, at the same time, satisfy current observational constraints. Assuming the two Swampland criteria are valid, we argue that the universe will undergo a phase transition within a few Hubble times. These criteria sharpen the motivation for future measurements of the tensor-to-scalar ratio r and the dark energy equation of state w, and for tests of the equivalence principle for dark matter.

AB - We study constraints imposed by two proposed string Swampland criteria on cosmology. These criteria involve an upper bound on the range traversed by scalar fields as well as a lower bound on |∇ϕV|/V when V>0. We find that inflationary models are generically in tension with these two criteria. Applying these same criteria to dark energy in the present epoch, we find that specific quintessence models can satisfy these bounds and, at the same time, satisfy current observational constraints. Assuming the two Swampland criteria are valid, we argue that the universe will undergo a phase transition within a few Hubble times. These criteria sharpen the motivation for future measurements of the tensor-to-scalar ratio r and the dark energy equation of state w, and for tests of the equivalence principle for dark matter.

UR - http://www.scopus.com/inward/record.url?scp=85051399610&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051399610&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2018.07.040

DO - 10.1016/j.physletb.2018.07.040

M3 - Article

AN - SCOPUS:85051399610

SN - 0370-2693

VL - 784

SP - 271

EP - 276

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 -