Inverse problems in spectral theory address the challenge of reconstructing differential operators from observed spectral data. This field, rich in both theoretical and applied mathematics, underpins ...

Spectral theory provides a rigorous framework for analysing the eigenvalues and eigenfunctions of differential operators that play an essential role in mathematical physics. In particular, ...

In this paper we determine the relationship between the spectra of a continuous contraction semigroup on Hilbert space and properties of the resolvent of its infinitesimal generator. The methods rely ...

Proceedings of the National Academy of Sciences of the United States of America The National Academy of Sciences (NAS) is a private, nonprofit organization of the country’s leading researchers. The ...

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