| Abstract : | Magnetic fields are omnipresent in universe. They play important role in the formation of stars, galaxies and the accretion onto compact objects and the collimation of the relativistic jets of radio galaxies. It is intriguing to understand the origin of magnetic fields in such objects,which has scales comparable to the size of the system and ranges from micro-Gauss to kilo-Gauss strength. In the canonical dynamo theory, it is been shown that if fluid posses kinetic helicity on the average, it would lead to the generation of magnetic field at larger scales. Although, such a net helicity cannot be expected in all astrophysical settings. In particular, disc galaxies have sub-critical strength of kinetic helicity needed to trigger the instability to generate the magnetic field. Hence, the quest for alternative dynamo mechanism. In this talk, I will present my investigation of zero mean helicity fluctuations in the background of linear shear flows as a alternate kinematic dynamo mechanism. |
