The Mathematical Institute, University of Oxford, Eprints Archive

Wave Packet Pseudomodes of Variable Coefficient Differential Operators

Trefethen, Lloyd N. (2004) Wave Packet Pseudomodes of Variable Coefficient Differential Operators. Technical Report. Unspecified. (Submitted)



The pseudospectra of nonselfadjoint linear ordinary differential operators with variable coefficients are considered. It is shown that when a certain winding number or twist condition is satisfied, closely related to Hörmander's commutator condition for partial differential equations, \varepsilon-pseudoeigenfunctions of such operators for exponentially small values of \varepsilon exist in the form of localized wave packets. In contrast to related results of Davies and of Dencker, Sjöstrand, and Zworski, the symbol need not be smooth.

Item Type:Technical Report (Technical Report)
Subjects:O - Z > Ordinary differential equations
H - N > Numerical analysis
Research Groups:Numerical Analysis Group
ID Code:1183
Deposited By: Lotti Ekert
Deposited On:18 May 2011 07:14
Last Modified:29 May 2015 18:52

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