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Abstract We construct rotating hybrid axion-miniboson stars (RHABSs), which are asymptotically flat, stationary, axially symmetric solutions of (3+1)-dimensional Einstein–Klein–Gordon theory. RHABSs consist of an axion field (ground state) and a free complex scalar field (first excited state). The solutions of RHABSs have two types of nodes, including $$^1S^2S$$ 1 S 2 S state and $$^1S^2P$$ 1 S 2 P state. For different axion decay constants $$f_a$$ f a , we present the mass M of RHABSs as a function of the synchronized frequency, as well as the nonsynchronized frequency, and explore the mass M versus the angular momentum J for the synchronized frequency and the nonsynchronized frequency, respectively. Furthermore, we study the effect of axion decay constant $$f_a$$ f a and free scalar field mass $$\mu _f$$ μ f on the existence domain of the synchronized frequency $$\omega $$ ω .

Abstract In this paper we investigate the model of the anti-de Sitter gravity coupled to a Maxwell field and a free, complex scalar field, and construct a fully back-reacted holographic model of superconductor with excited states. With the fixed charge q, there exist a series of excited states of holographic superconductor with the corresponding critical chemical potentials. The condensates as functions of the temperature for the two operators $${\mathcal {O}}_1$$ O 1 and $${\mathcal {O}}_2$$ O 2 of excited states are also studied. For the optical conductivity in the excited states, we find that there exist the additional peaks in the imaginary and real parts of the conductivity. Moreover, the number of peaks corresponding to n-th excited state is equal to n.

Abstract Motivated by the recent studies of the novel asymptotically global $$\hbox {AdS}_4$$ AdS4 black hole with deformed horizon, we consider the action of Einstein–Maxwell gravity in AdS spacetime and construct the charged deforming AdS black holes with differential boundary. In contrast to deforming black hole without charge, there exists at least one value of horizon for an arbitrary temperature. The extremum of temperature is determined by charge q and divides the range of temperature into several parts. Moreover, we use an isometric embedding in the three-dimensional space to investigate the horizon geometry. The entropy and quasinormal modes of deforming charged AdS black hole are also studied in this paper. Due to the existence of charge q, the phase diagram of entropy is more complicated. We consider two cases of solutions: (1) fixing the chemical potential $$\mu $$ μ ; (2) changing the value of $$\mu $$ μ according to the values of horizon radius and charge. In the first case, it is interesting to find there exist two families of black hole solutions with different horizon radii for a fixed temperature, but these two black holes have same horizon geometry and entropy. The second case ensures that deforming charged AdS black hole solutions can reduce to standard RN–AdS black holes.

Abstract We construct a class of counterexamples to cosmic censorship in four dimensional Einstein–Born–Infeld theory with asymptotically anti-de Sitter boundary conditions, and investigate the effect of the Born–Infeld parameter b in comparison with the counterpart of Einstein–Maxwell theory. When a charged massive scalar field is included into the action, we find that this class of counterexamples to cosmic censorship would be removed if the charge of scalar fields is above the bound of charge $$q_{w}$$ qw . In particular, the bound of charge required to preserve cosmic censorship increases with the increasing of Born–Infeld parameter. Meanwhile, we also show the lower bounds on charge-to-mass ratio with the different values of Born–Infeld parameter.