L. Boulton

activity

19992002

collaborators

3 papers

math.SP2002

Projection methods for discrete Schrodinger operators

Lyonell S. Boulton

Let $H$ be the discrete Schrödinger operator $H u (n) := u (n - 1) + u (n + 1) + v (n) u (n)$ , $u (0) = 0$ acting on $l^{2} (Z^{+})$ where the potential $v$ is real-valued and $v (n) \to 0$ as $n\to \i…

math.SP2001

Spectral behaviour of a simple non-self-adjoint operator

L. S. Boulton

We investigate the spectrum of a typical non-self-adjoint differential operator $A D = - d^{2} / d x^{2} \otimes A$ acting on $\Lp(0,1)\otimes \mathbb{C}^2$, where $A$ is a $2 \times 2$ constan…

math.SP1999

Non-self-adjoint harmonic oscillator, compact semigroups and pseudospectra

Lyonell S. Boulton

We provide new information concerning the pseudospectra of the complex harmonic oscillator. Our analysis illustrates two different techniques for getting resolvent norm estimates.…