Drift and ion acoustic waves in an inhomogeneous electron-positron-ion plasma with temperature degeneracy and exchange-correlation effects

•The role of correlation and pressure degeneracy effects on drift and IAW waves.•Linear dispersion derived here gives several limiting cases of previous studies.•Boundedness condition for the existence of vortex structures is significantly modified.•Vortex structures can move with different speed than the drift speed or the IA speed.•The amplitude of the nonlinear structures increases by increasing the Mach number.•The present study can be helpful to understand the magnetized dense EPI plasma. Plasma is a complex system because of huge variation in density and temperature, on the basis of these variations, the importance of classical limit, relativistic effects and different types of quantum effects are decided. In dense plasmas, the quantum effects become important. Therefore, in the present manuscript we investigate the role of exchange correlation and pressure degeneracy effects on the propagation of drift and ion acoustic waves (IAW) in an inhomogeneous dense electron–positron-ion (EPI) plasma. Most of the work presented here is analytical and based on the quantum hydrodynamic model and Mathematica is used to draw the different plots for illustration of the results. The nonlinear vortex solution is obtained with the help of Larichev and Reznik technique. A general linear dispersion relation is derived in a degenerate plasma which gives the several limiting cases of previous studies. The drift wave and IAW driven dipolar vortex solution is discussed. It is noticed that boundedness condition for the existence of nonlinear structures is significantly modify. It is pointed out that obeying boundedness condition of the solution, the nonlinear structures can move with the drift speed or the acoustic speed or greater than both the speeds. It is also noticed that the amplitude of the structures increases by increasing the Mach number. The present study is relevant to dense plasma system, where EPI plasma exists.