optic properties of uranium-based compounds" Uranium-based compounds often show interesting magnetic properties and large polar Kerr rotations. Because of this, the wavelength and temperature dependencies of the polar Kerr rotation in several uranium-based compounds, including UMnzGez, UFe2, and UGa2, have been investigated. The Mn moments order ferromagnetically in UMnzGel below 380 K, and whi...

The four-dimensional Kerr-de Sitter and Kerr-AdS black hole metrics have cohomogeneity 2, and they admit a generalisation in which an additional parameter characterising a NUT charge is included. In this paper, we study the higher-dimensional Kerr-AdS metrics, specialised to cohomogeneity 2 by appropriate restrictions on their rotation parameters, and we show how they too admit a generalisation...

We present a new approach for analyzing band structures in one-dimensional Kerr-nonlinear photonic crystals. It combines the finite-difference time-domain method, based on the numerical simulation of oscillating dipole radiation, with the Kerr-nonlinear model. The approach is applied to analyze the band structures in Kerr-nonlinear one-dimensional photonic crystals as a function of the intensit...

We consider the Kerr de Sitter (Kerr-dS) black hole in various dimensions. Introducing a counterterm, we show that the total action of these spacetimes are finite. We compute the masses and the angular momentum of Kerr-dS spaces with one rotational parameter in four, five and seven dimensions. Also these conserved charges are computed for the case of Kerr-dS with two rotational parameters in fi...

The Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and the Galactic superluminal jet sources share the common spectral characteristic that they have extremely high disk temperatures which cannot be explained in the framework of the standard accretion disk model in the Schwarzschild metric. We examine several possibilities to solve this “too-hot” disk problem. In particula...

We obtain a characterization of the Kerr metric among stationary, asymptotically flat, vacuum spacetimes, which extends the characterization in terms of the Simon tensor (defined only in the manifold of trajectories) to the whole spacetime. More precisely, we define a three index tensor on any spacetime with a Killing field, which vanishes identically for Kerr and which coincides in the strictl...

The Kerr-Newman solution has g=2 as that of the Dirac electron and is considered as a model of spinning particle in general relativity. The Kerr geometry changes cardinally our representations on the role of gravity in the particle physics. We show that the Kerr gravitational field has a stringy local action and a topological peculiarity which are extended up to the Compton distances, and also ...