Operator-theoretic Clunie–Eremenko–Rossi conjecture

From papers

Let {αn}nN\{\alpha_n\}_{n\in\mathbb{N}} be unimodular complex numbers and let {βn}nN\{\beta_n\}_{n\in\mathbb{N}} be positive numbers converging to 00, with the ratios αnβn1\alpha_n\beta_n^{-1} distinct. Define operators on a Hilbert space H\mathcal{H} with orthonormal basis {en}\{\mathbf e_n\} by

Aen=αnen,Ben=βnen.A\mathbf e_n=\alpha_n\mathbf e_n,\qquad B\mathbf e_n=\beta_n\mathbf e_n.

Thus AA is unitary and BB is compact selfadjoint. For a totally non-zero unit vector v\mathbf v, let PP be the orthoprojection onto K=v\mathcal{K}=\mathbf v^\perp, and set A=PAPKA'=PAP|_{\mathcal{K}} and B=PBPKB'=PBP|_{\mathcal{K}}. Operator-theoretic Clunie–Eremenko–Rossi conjecture. The BB'-point spectrum of AA' is infinite:

ΣB(A)=,|\Sigma_{B'}(A')|=\infty,

that is, there are infinitely many zCz\in\mathbb{C} such that N(AzB){0}N(A'-zB')\ne\{0\}. This is presented as equivalent to the classical Clunie–Eremenko–Rossi conjecture; the supplied text gives no resolution.

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Sources & referencesView supporting material

Primary source

Julius Borcea, “Equilibrium points of logarithmic potentials induced by positive charge distributions. I. Generalized de Bruijn-Springer relations”, arXiv:math/0601519 (2006).

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