Constraints on Dark Energy Models from Weak Gravity Conjecture
  We study the constraints on the dark energy model with constant equation of state parameter $w=p/\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $w<-0.7$ at the $3\sigma$ confidence level. The holographic dark energy model realized by a scalar field is in swampland. 
Ximing Chen, Jie Liu, Yungui Gong