Extensions of the fundamental theorem of algebra

In this paper motivated by the celebrated fundamental theorem of algebra and its standard proof utilizing Liouville's Theorem, we prove the fundamental theorem of algebra type results for both commutative and noncommutative polynomials in the setting of left (resp. right) alternative topological complex algebras whose topological duals separates their elements and that of such real algebras whose centers contain certain copies of complex numbers. An application of one of the main results of the paper is the existence of eigenvalues for matrices with entries from arbitrary finite-dimensional complex algebras. We also prove the existence of right eigenvalues for matrices with entries from finite-dimensional associative real algebras that contain copies of the complex numbers.Comment: in this version: we improved Theorems 2.2 and 2.3 and fixed a trivial mistake as well as some typo

Iranian mathematics competitions 1973–2007

A collection of problems from a competition for college students organised by the Iranian Mathematical Society. It compiles problems from these competitions between 1973 and 2007 and provides solutions to most of them. It is suitable for students of mathematics preparing for competitions and for advanced studies

On simultaneous triangularization of collections of compact operators

AbstractIn this paper we consider collections of compact (resp. Cp class) operators on arbitrary Banach (resp. Hilbert) spaces. For a subring R of reals, it is proved that an R-algebra of compact operators with spectra in R on an arbitrary Banach space is triangularizable if and only if every member of the algebra is triangularizable. It is proved that every triangularizability result on certain collections, e.g., semigroups, of compact operators on a complex Banach (resp. Hilbert) space gives rise to its counterpart on a real Banach (resp. Hilbert) space. We use our main results to present new proofs as well as extensions of certain classical theorems (e.g., those due to Kolchin, McCoy, and others) on arbitrary Banach (resp. Hilbert) spaces