Dynamics and cosmological constraints on Brans-Dicke cosmology

Understand

We investigate observational constraints on the Brans-Dicke cosmological model using observational data coming from distant supernovae type Ia, the Hubble function $H(z)$ measurements, information coming from the Alcock-Paczy{\'n}ski test, and baryon acoustic oscillations.

• Our analysis is based on the modified Friedmann function resulting form dynamical investigations of Brans-Dicke cosmology in the vicinity of a de Sitter state.
• The qualitative theory of dynamical systems enables us to obtain three different behaviors in the vicinity of this state.
• We find for a linear approach to the de Sitter state $\omega_{\textrm{BD}}=-0.8606^{+0.8281}_{-0.1341}$, for an oscillatory approach to the de Sitter state $\omega_{\textrm{BD}}=-1.1103^{+0.1872}_{-0.1729}$, and for the transient de Sitter state represented by a saddle-type critical point $\omega_{\textrm{BD}}=-2.3837^{+0.4588}_{-4.5459}$.