On the oscillation of second order quasilinear elliptic equations

By using the Riccati technique, some oscillation criteria for the second order quasilinear elliptic equation ∑ i , j = 1 N D i [ Φ ( y ) A i j ( x ) | D y | p − 2 D j y ] + p ( x ) f ( y ) = 0 are established. These results contain the known oscillation theorems from the literature as special cases.