Molecular beam epitaxial growth and thermodynamic analysis of InGaAs and InAlAs lattice matched to InP

Reflection high-energy electron diffraction (RHEED) intensity oscillations have been used to detect the onset of metal droplet formation on the surface of InAs, InGaAs and InAlAs during molecular beam epitaxy. The growth conditions which produce such droplets are shown to be in good agreement with predictions based on thermodynamic arguments.     

Using permutation rational functions to obtain permutation arrays with large hamming distance

Designs, Codes and Cryptography - We consider permutation rational functions (PRFs), V(x)/U(x), where both V(x) and U(x) are polynomials over a finite field $$\mathbb {F}_q$$ . Permutation rational...     

On semilinear elliptic equations with indefinite nonlinearities

This paper concerns semilinear elliptic equations whose nonlinear term has the formW(x)f(u) whereW changes sign. We study the existence of positive solutions and their multiplicity. The important role played by the negative part ofW is contained in a condition which is shown to be necessary for homogeneousf. More general existence questions are also discussed.Supported in part by NSF grant DMS9003149.     

Realism in quantum mechanics

We first present a realistic framework for quantum probability theory based on the path integral formalism of quantum mechanics and illustrate this framework by constructing a model that describes a quantum particle evolving in a discrete space-time lattice. We then present a finite model for describing the internal dynamics of elementary particles and show that this model gives the standard particle classification scheme and successfully predicts particle masses.     

Eigenvalue branches of the Schrödinger operatorH−λW in a gap of σ(H)

The authors study the eigenvalue branches of the Schrödinger operatorH — W in a gap of (H). In particular, they consider questions of asymptotic distribution of eigenvalues and bounds on the number of branches. They also address the completeness problem.     

An essay on skew translation generalized quadrangles

Astract We study a class of generalized quadrangles satisfying a local Moufang condition that is more restrictive than the usual concept of skew translation GQ. A new infinite family is constructed whose point-line duals are translation generalized quadrangles with very small kernel. They have parameters (q ², q), q=3 ^r , for r>2.This paper was written while the author was supported by the CNR as a visiting professor at the University of Rome La Sapienza.