abstract the spontaneous emission spectrum from a driven three-level atom placed inside a double-band photonic crystal has been investigated. we use the model which assumes the upper levels of the atomic transition are coupled via a classical driving field. the transition from one of the upper levels to lower level couples to the modes of the modified reservoir, and the transition from the othe...

In this essay, I make the case that the intersectionality framework is useful to explain the high level of obesity among Black women. I describe how the intersectionality framework reformulates the examination of racial and gender disparities in health by deconstructing traditional frames of Whiteness and maleness. Next, I discuss key barriers that operate as mechanisms to reduce Black women’s ...

In flat space, the extreme Reissner-Nordstrøm (RN) black hole is distinguished by its coldness (vanishing Hawking temperature) and its supersymmetry. We examine RN solutions to Einstein-Maxwell theory with a cosmological constant Λ, classifying the cold black holes and, for positive Λ, the " lukewarm " black holes at the same temperature as the de Sitter thermal background. For negative Λ, we c...

Static solutions of 5-dimensional gravity with two spatial Killing vectors are characterized by their rod structures. In this note we describe how the orbifold singularities and the topologies of the horizons and asymptotic regions can be determined from the corresponding rod diagrams. As an example we introduce the black lens, a static 5-dimensional black hole with a horizon of lens space topo...

The (single) black hole solutions of Ba~ nados, Teitelboim and Zanelli (BTZ) in 2+1 dimensional anti-de Sitter space are generalized to an arbitrary number n of such black holes. The resulting multi-black-hole (MBH) spacetime is locally isometric to anti-de Sitter space, and globally it is obtained from the latter as a quotient space by means of suitable identiications. The MBH spacetime has n ...

The (single) black hole solutions of Bañados, Teitelboim and Zanelli (BTZ) in 2+1 dimensional anti-de Sitter space are generalized to an arbitrary number n of such black holes. The resulting multi-black-hole (MBH) spacetime is locally isometric to anti-de Sitter space, and globally it is obtained from the latter as a quotient space by means of suitable identifications. The MBH spacetime has n a...

When a black hole is put in an empty space (zero temperature space) on which there is no matter except the matter of the Hawking radiation (Hawking field), then an outgoing energy flow from the black hole into the empty space exists. By the way, an equilibrium between two arbitrary systems can not allow the existence of an energy (heat) flow from one system to another. Consequently, in the case...

A black hole and a black hyperboloid solutions in the space with the Schrödinger isometries are presented and their thermodynamics is examined. The on-shell action is obtained by the difference between the extremal and non-extremal ones with the unusual matching of the boundary metrics. This regularization method is first applied to the black brane solution in the space of the Schrödinger symme...

In recent work on black hole entropy in non-perturbative quantum gravity, an action for the black hole sector of the phase space is introduced and (partially) quantized. We give a number of observations on this and related works. In particular we show that (i) the entropy calculation applies without change to generally covariant theories having no black hole solutions, (ii) the phase space cons...

String theory can accommodate black holes with the black hole parameters related to string moduli. It is a well known but remarkable feature that the near horizon geometry of a large class of black holes arising from string theory contains a BTZ part. A mathematical theorem (Sullivan’s Theorem) relates the three dimensional geometry of the BTZ metric to the conformal structures of a two dimensi...