Obtaining a scalar fifth force via a broken-symmetry couple between the scalar field and matter

Understand

A matter-coupled scalar field model is presented in obtaining a scalar fifth force when the constraint of the current cosmological constant is satisfied.

• The interaction potential energy density between the scalar field and matter has a symmetry-breaking form with two potential wells.
• The cosmological constant is proven to be a value of the scalar-field's self-interaction potential energy density at the minimum of an effective matter-density-dependent potential energy density.
• The effective potential is a sum of the interaction potential and the self-interaction potential of the scalar field.