CMB Anisotropy Induced by Tachyonic Perturbations of Dark Energy

摘要

We consider the effects of possible tachyonic perturbations of dark energy on the CMB anisotropy. Such perturbations emerge, in particular, in models with phantom dark energy violating Lorentz invariance. Therefore, we discuss tachyonic perturbations with a Lorentz-violating dispersion relation. We show that the corresponding contribution to the CMB anisotropy can have an appreciable amplitude, while the angular spec_trum has a distinct maximum. These predictions are compared with observational data. The tachyonic contri_bution slightly improves the agreement between the theory and observations, but this improvement is statisti_cally insignificant and our analysis gives constraints on the tachyonic perturbation amplitude.