On the Riesz basis property of root vectors system for 2 × 2 Dirac type operators

The paper is concerned with the Riesz basis property of a boundary value problem associated in L2[0,1]⊗C2L2[0,1]⊗C2 with the following 2×22×2 Dirac type equationequation(0.1)Ly=−iB−1y′+Q(x)y=λy,B=(b100b2),y=col(y1,y2), with a summable potential matrix Q∈L1[0,1]⊗C2×2Q∈L1[0,1]⊗C2×2 and b1<0