Funktionalgleichungen in reellen Verktorräumen und verallgemeinerte Cauchy-Riemannsche Differentialgleichungen, speziell die Weylsche Gleichung des Neutrinos. (Short Communication).
The author considers the operator equation . Methods for acceleration of convergence of the iterative process are investigated.
Four applications are outlined of pseudospectra of highly nonnormal linear operators.
We investigate the existence of the solution to the following problem min φ(x) subject to G(x)=0, where φ: X → ℝ, G: X → Y and X,Y are Banach spaces. The question of existence is considered in a neighborhood of such point x₀ that the Hessian of the Lagrange function is degenerate. There was obtained an approximation for the distance of solution x* to the initial point x₀.
An exactness lemma offers a simplified account of the spectral properties of the "holomorphic" analogue of normal solvability.