A compact regular operator without modulus

Linear Modulus of a Linear Operator

Struwe’s decomposition for a Polyharmonic operator on a compact Riemannian manifold with or without boundary

Modulus of convexity for operator convex functions

Most of the interesting examples deal with operators that are positive semi-definite. We shall follow the same convention in this paper. Operator convex functions are known to satisfy a number of interesting properties. An important discovery was made by Hansen and Pederson, who used Eq.1 in order to obtain an operator generalization of the Jensen inequality.[1] Recently, Effros provided an ele...

LASERS WITHOUT INVERSION: DENSITY OPERATOR METHOD

A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...

The Norm and Modulus of a Foguel Operator

We develop a method for calculating the norm and the spectrum of the modulus of a Foguel operator. In many cases, the norm can be computed exactly. In others, sharp upper bounds are obtained. In particular, we observe several connections between Foguel operators and the Golden Ratio.