Kaluza-Klein models

Below we present the idea of self-interacting dark matter and gravitationally-produced WIMPZILLAs. Other interesting candidates have been proposed recently in models with extra dimensions, such as Kaluza-Klein dark matter ( Cheng, Feng Matchev (2002)) and branons (Cembranos, Dobado Maroto (2003)). 

Unification of the gravitational and electromagnetic fields was achieved qualitatively in terms of the Kaluza-Klein (KK) five-dimensional model (4.6). 

On the theoretical side, simple cosmological models with a varying fine structure constant have now been developed (see, for example, Sandvik et al., 2002 Barrow etal., 2002b). They share some properties with Kaluza-Klein-type models in which a varies at the same rate as the extra dimensions of space (see, for example, Damour and Polyakov, 1994) and with varying-speed-of-light theories (see, for example, Albrecht and Magueijo, 1999 Barrow and Magueijo, 2000). 

Ponce de Leon, J. (1988) Cosmological models in Kaluza-Klein theory with variable rest mass, Gen. Rel. Grav., 1988 (20) 539-550. 

The model produced nothing beyond Kaluza s original and confirmed the periodicity condition observed by Klein - a mathematical consequence of a closed system. The coordinates they used to describe the closed fivedimensional space are strangely reminiscent of the homogeneous coordinates of four-dimensional projective geometry, but without a point at infinity. 

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