## 34E20 Singular perturbations, turning point theory, WKB methods

### Refine

#### Has Fulltext

- yes (4)

#### Document Type

- Preprint (4)

#### Language

- English (4)

#### Is part of the Bibliography

- yes (4)

#### Keywords

- singular perturbation (2)
- asymptotic methods (1)
- asymptotics (1)
- dynamical system (1)
- ellipticity with parameter (1)
- lattice point (1)
- logarithmic residue (1)
- pseudodifferential operator (1)
- regularization (1)

#### Institute

The paper is devoted to asymptotic analysis of the Dirichlet problem for a second order partial differential equation containing a small parameter multiplying the highest order derivatives. It corresponds to a small perturbation of a dynamical system having a stationary solution in the domain. We focus on the case where the trajectories of the system go into the domain and the stationary solution is a proper node.

We develop a new approach to the analysis of pseudodifferential operators with small parameter 'epsilon' in (0,1] on a compact smooth manifold X. The standard approach assumes action of operators in Sobolev spaces whose norms depend on 'epsilon'. Instead we consider the cylinder [0,1] x X over X and study pseudodifferential operators on the cylinder which act, by the very nature, on functions depending on 'epsilon' as well. The action in 'epsilon' reduces to multiplication by functions of this variable and does not include any differentiation. As but one result we mention asymptotic of solutions to singular perturbation problems for small values of 'epsilon'.