Models of phase stability in Jackiw-Teitelboim gravity

Abstract: We construct solutions within Jackiw-Teitelboim (JT) gravity in the presence of nontrivial couplings between the dilaton and the Abelian $1$-form where we analyse the asymptotic structure as well as the phase stability corresponding to charged black hole solutions in $1+1$ D. We consider the Almheiri-Polchinski (AP) model as a specific example within $1+1$ D JT gravity which plays a pivotal role in the study of Sachdev-Ye-Kitaev (SYK)/anti-de Sitter (AdS) duality. The corresponding vacuum solutions exhibit a rather different asymptotic structure than their uncharged counterpart. We find interpolating vacuum solutions with AdS$2$ in the IR and Lifshitz$_2$ in the UV with dynamical exponent $z{\text{dyn}}=3/2$. Interestingly, the presence of charge also modifies the black hole geometry from asymptotically AdS to asymptotically Lifshitz with same value of the dynamical exponent. We consider specific examples, where we compute the corresponding free-energy and explore the thermodynamic phase stability associated with charged black hole solutions in $1+1$ D. Our analysis reveals the existence of a universal thermodynamic feature that is expected to reveal its immediate consequences on the dual SYK physics at finite density and strong coupling.