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Kerr-Anti-De-Sitter/De-Sitter Black Hole In Perfect Fluid Dark Matter Background (1711.04538v2)

Published 13 Nov 2017 in gr-qc

Abstract: We obtain the Kerr-anti-de-sitter (Kerr-AdS) and Kerr-de-sitter (Kerr-dS) black hole (BH) solutions to the Einstein field equation in the perfect fluid dark matter background using the Newman-Janis method and Mathematica package. We discuss in detail the black hole properties and obtain the following main results: (i) From the horizon equation $g_{rr}=0$, we derive the relation between the perfect fluid dark matter parameter $\alpha$ and the cosmological constant $\Lambda$ when the cosmological horizon $r_{\Lambda}$ exists. For $\Lambda=0$, we find that $\alpha$ is in the range $0<\alpha<2M$ for $\alpha>0$ and $-7.18M<\alpha<0$ for $\alpha<0$. For positive cosmological constant $\Lambda$ (Kerr-AdS BH), $\alpha_{max}$ decreases if $\alpha>0$, and $\alpha_{min}$ increases if $\alpha<0$. For negative cosmological constant $-\Lambda$ (Kerr-dS BH), $\alpha_{max}$ increases if $\alpha>0$ and $\alpha_{min}$ decreases if $\alpha<0$; (ii) An ergosphere exists between the event horizon and the outer static limit surface. The size of the ergosphere evolves oppositely for $\alpha>0$ and $\alpha<0$, while decreasing with the increasing $\mid\alpha\mid$. When there is sufficient dark matter around the black hole, the black hole spacetime changes remarkably; (iii) The singularity of these black holes is the same as that of rotational black holes. In addition, we study the geodesic motion using the Hamilton-Jacobi formalism and find that when $\alpha$ is in the above ranges for $\Lambda=0$, stable orbits exist. Furthermore, the rotational velocity of the black hole in the equatorial plane has different behaviour for different $\alpha$ and the black hole spin $a$. It is asymptotically flat and independent of $\alpha$ if $\alpha>0$ while is asymptotically flat only when $\alpha$ is close to zero if $\alpha<0$.

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