P-VCriticality of Conformal Anomaly Corrected AdS Black Holes

The effects of conformal anomaly on the thermodynamics of black holes are investigated in this paper from the perspective ofP-Vcriticality of AdS black holes. Treating the cosmological constant as thermodynamic pressure, we extend the recent research to the extended phase space. Firstly, we study theP-Vcriticality of the uncharged AdS black holes with conformal anomaly and find that conformal anomaly does not influence whether there exists Van der Waals like critical behavior. Secondly, we investigate theP-Vcriticality of the charged cases and find that conformal anomaly influences not only the critical physical quantities but also the ratioPcrc/Tc. The ratio is no longer a constant as before but a function of conformal anomaly parameterα~. We also show that the conformal parameter should satisfy a certain range to guarantee the existence of critical point that has physical meaning. Our results show the effects of conformal anomaly.

PRE-INFLATION IN THE PRESENCE OF CONFORMAL COUPLING

We consider a massless scalar field, conformally coupled to the Ricci scalar curvature, in the pre-inflation era of a closed FLRW Universe. The scalar field potential can be of the form of the Coleman–Weinberg one-loop potential, which is flat at the origin and drives the inflationary evolution. For positive values of the conformal parameter ξ, less than the critical value ξ c =(1/6), the model admits exact solutions with nonzero minimum scale factor and zero initial Hubble parameter. Thus these solutions can be matched smoothly to the so-called Pre-Big-Bang models. At the end of this pre-inflation era one can match inflationary solutions by specifying the form of the potential and the whole solution is of the class C(1).