On the Riesz Inequality and the Basicity of Systems of Root Vector Functions of 2mth-Order Dirac-Type Operator with Summable Coefficient

We consider a Dirac-type operator of $$2m$$ th order on a finite interval $$G = (a,b).$$ It is assumed that its coefficient is a complex-valued matrix function summable on $$G = (a,b)$$ . A Riesz property criterion is established for a system of root vector functions, and a theorem on the equivalent basis property in $$L_{p}^{{2m}}(G)$$ , $$1 < p < \infty $$ , is proved.