This volume presents recent advancements in operator theory and its diverse applications, stemming from the International Workshop on Operator Theory and Its Applications (IWOTA 95). The workshop, held at the University of Regensburg, covered a broad spectrum of topics including linear and nonlinear spectral problems, abstract operators, spectral theory of ordinary and partial operators, pseudodifferential operators, and integral operators. It also delved into operator theory in spaces with indefinite metric, operator functions, and interpolation and extension problems. The proceedings aim to update readers on current achievements in these fields, with a companion volume focusing specifically on differential and integral operators.

This collection of papers from IWOTA 95 offers a comprehensive overview of recent developments in operator theory and its applications. The contributions are expected to be of practical use to a wide readership across pure and applied mathematics, physics, and engineering sciences. The dual-volume format ensures that readers receive up-to-date information on a broad range of specialized topics within the field. The workshop's focus on both theoretical advancements and practical applications highlights the continued relevance and dynamism of operator theory.