Anisotropic 2-form dark energy

Abstract

We study the dynamics of dark energy in the presence of a 2-form field coupled to a canonical scalar field ϕ. We consider the coupling proportional to e−μϕ/MplHαβγHαβγ and the scalar potential V(ϕ)∝e−λϕ/Mpl, where Hαβγ is the 2-form field strength, μ,λ are constants, and Mpl is the reduced Planck mass. We show the existence of an anisotropic matter-dominated scaling solution followed by a stable accelerated fixed point with a non-vanishing shear. Even if λ≥O(1), it is possible to realize the dark energy equation of state wDE close to −1 at low redshifts for μ≫λ. The existence of anisotropic hair and the oscillating behavior of wDE are key features for distinguishing our scenario from other dark energy models like quintessence.