Constraints on oscillating dark energy models

The oscillating scenario of route to Lambda was recently proposed by us [O. Hrycyna, M. Szydlowski, Phys. Lett. B 651 (2007) 8, arXiv: 0704.1651 [hep-th]] as an alternative to a cosmological constant in a explanation of the current accelerating universe. In this scenario phantom scalar field conformally coupled to gravity drives the accelerating phase of the universe. In our model ΛCDM appears as a global attractor in the phase space. In this Letter we investigate observational constraints on this scenario from recent measurements of distant supernovae type Ia, H(z) observational data, CMB R shift and BAO parameter. The Bayesian methods of model selection are used in comparison the model with concordance ΛCDM one as well as with model with dynamical dark energy parametrised by linear form. We conclude that ΛCDM is favoured over FRW model with dynamical oscillating dark energy. Our analysis also demonstrate that FRW model with oscillating dark energy is favoured over FRW model with decaying dark energy parametrised in linear way.