Effect of the Global Rotation of the Universe on the Formation of Galaxies

The effect of the global rotation of the universe on the formation of galaxies is investigated. It is found that the global rotation provides a natural origin for the rotation of galaxies, and the morphology of the objects formed from gravitational instability in a rotating and expanding universe depends on the amplitude of the density fluctuation, different values of the amplitude of the fluctuation lead to the formation of elliptical galaxies, spiral galaxies, and walls. The global rotation gives a natural explanation of the empirical relation between the angular momentum and mass of galaxies: J ∝ M5/3. The present angular velocity of the universe is estimated, which is ∼ 10−13 rad yr−1. Subject headings: cosmology: theory — galaxies: formation — galaxies: general In a homogeneous universe which is more general than the Friedmann model, the matter may not only expand but also rotate relative to local gyroscopes. The rotation of the matter in the universe as a whole is usually called the global rotation of the universe, which has been investigated by many scientists (Gamow 1946, Gödel 1949 & 1990, Ellis 1971, Obukhov 1992, Korotky & Obukhov 1996). People usually think that the observed isotropy of the cosmic microwave background (CMB) strongly restricts the possible value of the angular velocity of the universe (Collins & Hawking 1973, Hawking 1974). However, when more general cosmological models are considered, the restriction may be much looser (Matzner 1997). For the Bianchi IX models the more realistic limits are thought to be of the order 10−12 rad yr−1 (Ciufolini & Wheeler 1995). And more, some recent investigations reveal that there are a wide class of viable cosmological models for which the global rotation does not influence the isotropy of CMB at all and it is the shear which may affect the isotropy of CMB (Obukhov 1990, Korotky & Obukhov 1991 & 1996, Pavelkin & Panov 1995). Therefore it is significant to investigate the cosmic effects of the global rotation further. E-mail address: [email protected]