  We carry out Particle-in-Cell (PIC) simulations to study the instabilities
associated with a 2-D sheared electron flow configuration against a
neutralizing background of ions. Both weak and strong relativistic flow
velocities are considered. In the weakly relativistic case, we observe the
development of electromagnetic Kelvin Helmholtz instability with similar
characteristics as that predicted by the electron Magnetohydrodynamic (EMHD)
model. On other hand, in strong relativistic case the compressibility effects
of electron fluid dominate and introduce upper hybrid electrostatic
oscillations transverse to the flow which are very distinct from EMHD fluid
behaviour. In the nonlinear regime, both weak and strong relativistic cases
lead to turbulence with broad power law spectrum.
