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arXiv · 2608.18600

Inverse Feshbach's problem: Solvability and solutions

Miloslav Znojil
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Abstract

Given a certain specific, $M$ by $M$ matrix form of the Feshbach's effective (i.e., energy-dependent) Hamiltonian $H^{(M)}_{e\!f\!f}(E)$, the inverse-problem reconstruction of the full-space, $N$ by $N$ matrix Hamiltonian $H^{(N)}$ is considered and reduced to the solution of a coupled set of polynomial algebraic equations. Using computer-assisted symbolic manipulations, an explicit algebraic reconstruction of $H^{(N)}$ is found feasible at not too large $K = N-M$.

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Miloslav Znojil. 2026-08-19. Inverse Feshbach's problem: Solvability and solutions. https://doi.org/10.1088/1402-4896%2Faea0af

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