In this paper we introduce a method called Dirac Assisted Tree (DAT)  , which can handle  heterogeneous Helmholtz equations with arbitrarily large variable wave numbers.
<meaning-changed> In this paper we introduce a method called Dirac Assisted Tree (DAT)  , which can handle  heterogeneous Helmholtz equations with arbitrarily large variable wave numbers.
In this paper we introduce a method called Dirac Assisted Tree (DAT) , which can handle 1D heterogeneous Helmholtz equations with arbitrarily large variable wave numbers.