Is Gravity the Weakest Force?

Understand

It has recently been suggested that "gravity is the weakest force" in any theory with a suitable UV completion within quantum gravity.

• One formulation of this statement is the scalar weak gravity conjecture, which states that gravity is weaker than the force originating from scalar fields.
• We study the scalar weak gravity conjecture in de Sitter space, and discuss its low-energy consequences in light of the experimental searches for fifth forces and violations of the equivalence principle.
• We point out that some versions of the scalar weak gravity conjecture forbid the existence of very light scalar particles, such as the quintessence and axion-like particles.