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Gravitational AdS to dS phase transition in Einstein-Maxwell-Gauss-Bonnet gravity

In this work, we revisit a toy model proposed by Camanho {\it et.al.} [JHEP 10 (2015) 179] and extensively study the possible existence of gravitational phase transition from AdS to dS geometries by adding the Maxwell field as an impurity substitution. We show that the phase transitions proceed via the bubble nucleation of spherical thin-shells described by different branches of the solution which host a black hole in the interior. In order to demonstrate the existence of the phase transition, we examine how the free energy and temperature depend on the higher-order gravity coupling $(λ)$ indicating the possibility of thermalon mediated phase transition. We observe that the phase transitions of the charged case is possible in which the required (maximum) temperature is lower than that of the neutral case. Interestingly, we also discover that the critical temperature and the coupling $λ$ of the phase transitions are modified when having the charge. In addition, our results agree with the claim that the generalized gravitational phase transition is a generic behavior of the higher-order gravity theories even the matter field is added.