Searching extra dimensions in compact stars

The electro-magnetic and particle radiation detected from the direction of Cygnus X3 raise the question of the existence of special long-lived, neutral particles. We investigate the origin of these particles in a special approach: the source object may contain compactified extra dimension and these particles are messengers of this state. We describe hyperon stars in 3 + 1 dimension and introduce the description of a compact stars in 3 + 1(c) + 1 dimensional space-time. (c) 2007 WILEY-VCH Verlag GmbH&Co. KGaA, Weinheim.