Publikace ÚTF

We present an improved metric form of the complete family of exact black hole spacetimes of algebraic type D, including any cosmological constant. This class was found by Debever in 1971, Plebański and Demiański in 1976, and conveniently reformulated by Griffiths and Podolský in 2005. In our new form of this metric the key functions are simplified, partially factorized, and fully explicit. They depend on seven parameters with direct physical meanings, namely m, a, l, α, e, g, Λ which characterize mass, Kerrlike rotation, NUT parameter, acceleration, electric and magnetic charges of the black hole, and the cosmological constant, respectively. Moreover, this general metric reduces directly to the familiar forms of (possibly accelerating) Kerr-Newman–(anti–)de Sitter spacetime, charged Taub-NUT–(anti–)de Sitter solution, or (possibly rotating and charged) C-metric with a cosmological constant by simply setting the corresponding parameters to zero. In addition, it shows that the Plebański-Demiański family does not involve accelerating NUT black holes without the Kerr-like rotation. The new improved metric also enables us to study various physical and geometrical properties, namely the character of singularities, two black hole and two cosmo-acceleration horizons (in a generic situation), the related ergoregions, global structure including the Penrose conformal diagrams, parameters of cosmic strings causing the acceleration of the black holes, their rotation, pathological regions with closed timelike curves, or thermodynamic quantities.