Peter Harper

Norm Estimates of Harper Operators

n denotes the canonical orthonormal basis in l2. The study of the spectral properties of this class of operators has attracted a significant amount of interest in the past couple of decades (see [5], [3], [8], [1], [10], [14], [12], [7] for some of the most important developments). Most of this work has focused on the “Ten Martini problem” of M. Kac, concerning the possible values of the labels...

Quantum diffusion in the generalized Harper equation

We study numerically the dynamic and spectral properties of a one-dimensional quasi-periodic system, where site energies are given by k = V cos 2πf xk with xk denoting the kth quasiperiodic lattice site. When 2πf is given by the reciprocal lattice vector G(m, n) with n and m being successive Fibonacci numbers, the variance of the wavepacket is found to grow quadratically in time, regardless of ...

JALDA's Interview with Peter Mühlhäusler

Peter Mühlhäusler is the Foundation Professor of Linguistics at the University of Adelaide, and Supernumerary Fellow of Linacre College, Oxford. He has taught at the Technical University of Berlin and in the University of Oxford. He is an active researcher in several areas of linguistics, including ecolinguistics, language planning, and language policy and language contact in the Australian-Pac...

Harper skirts transparency on foreign aid.

Peter Marshall

This paper outlines and analyses the behaviours of small and medium enterprises with respect to the evaluation of electronic commerce investments, and the subsequent realisation of the anticipated benefits from those investments. The responses of executives who participated in the study suggested that on-going involvement in electronic commerce did not come cheaply. Nonetheless, our study sugge...