2 00 9 Rotation and helicity as dynamo generators in dissipative and ideal plasma cosmologies July 22 , 2009

Recently Kleides et al [IJMPA 11, 1697 (2008)] found a growing rate for magnetic fields in ideal plasma cosmologies by making use of general relativistic Friedmann model. This growth rate of δB B ∼ (t t H) 1 4 indicates the presence of a slow dynamo in the universe. More recently Hasseein [Phys Plasmas (2009)] have also investigate Beltrami magnetic fields in plasma universe. Here general relativistic(GR) MHD dynamo equation, recently given by Clarkson and Marklund [Monthly Not Roy Astr Soc (2005)] is used to investigate the relation between collapsing of the isotropic universe and dynamo action in ideal and dissipative cosmologies. Dynamo action can be supported in these phases as long as the kinetic helicity overcomes universe diffusion effects. A cosmological Beltrami flow in 3D shows that helicities may act constructively on gravitational collapse and enhance dynamo action. A slow dynamo action is found in the static Einstein universe also filled with a Beltrami flow. A rotating, shear-free Bianchi type-IX universe, is obtained, by