00000nam a2200000 a 4500 20251219155950.0 9783030380014 515.7 BOR Borthwick, David _ Spectral theory basicsa concepts and applications switzerland Springer 2020 x, 338p. 22cm. HB Graduate texts in Mathematics includes index _ Spectral theory Functional analysis _ _ _ 230775 315084 315084 0 0 0 0 PU PU 2025-02-19 4360.07 0 515.7 BOR 230775 BK