SearcharxivSearch

arXiv · 2306.12395

On Some Problems of Operator Theory and Complex Analysis

Abstract

In 1955 Kadison \cite{14} asked whether the analogue of the classical Burnside's theorem of the Linear Algebra holds in the infinite dimensional case. We use reproducing kernels method to solve the Kadison question. Namely, we prove that any proper weakly closed subalgebra $\mathcal{A}$ of the algebra $\mathcal{B}\left( H\right) $ of bounded linear operators on infinite dimensional complex Hilbert spaces $H$ has a nontrivial invariant subspace, i.e., $\mathcal{A}$ is a nontransitive algebra. This solves The Transitive Algebra Problem positively, and hence Hyperinvariant Subspace Problem and Invariant Subspace Problem are also solved positively. In this context, we also consider the celebrated Riemann Hypothesis of the theory of meromorphic functions and solve it in negative.

Explore related subjects

Keep this discovery

BibTeXRIS

Mubariz T. Garayev. 2023-06-19. On Some Problems of Operator Theory and Complex Analysis. https://arxiv.org/abs/2306.12395

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Average Chord Lengths in a Triangle

Let $P$ be a point inside a triangle $T$. We consider the average length of the chords of $T$ through $P$, where the direction of the chord is chosen uniformly. An elementary formula is obtained in terms of the distances from $P$ to the sides and vertices of the triangle. Several classical triangle centers give especially simple specializations. For example, if $I$ is the incenter, then \[ M_T(I)=\frac{2r}{\pi} \log\left(\cot\frac A4\cot\frac B4\cot\frac C4\right). \] Our main result is the sharp inequality \[ M_T(P)\le \frac{p}{\pi\sqrt3}\log(2+\sqrt3), \] valid simultaneously for every triangle of perimeter $p$ and every interior point $P$. Thus, among all such pairs $(T,P)$, the largest possible average chord length occurs only when $T$ is equilateral and $P$ is its center. The proof is an elementary symmetrization argument. We close with brief remarks relating the problem to the radial center of a convex body, the electrostatic potential center of a triangle, and dual quermassintegrals.

math.GM

A Proof of Liu's Conjecture on the Fundamental Triangle Inequality

Let $a,b,c$ be the side lengths of a triangle, and let $R$ and $r$ denote its circumradius and inradius, respectively. We prove a conjecture of Liu stating that \[\sum_{\mathrm{cyc}} \left(\frac{a(b+c-a)}{bc}\right)^k \geq 2+\left(\frac{2r}{R}\right)^k,~~k>1, \] with the reverse inequality for $0<k<1$. The proof reduces the problem to three positive variables with fixed sum and product. We also determine the equality cases.

math.GM