Opuscula Math. 38, no. 5 (2018), 597-621
https://doi.org/10.7494/OpMath.2018.38.5.597
Opuscula Mathematica
The spectral theorem for locally normal operators
Abstract. We prove the spectral theorem for locally normal operators in terms of a locally spectral measure. In order to do this, we first obtain some characterisations of local projections and we single out and investigate the concept of a locally spectral measure.
Keywords: locally Hilbert space, locally \(C^*\)-algebra, locally normal operator, local projection, locally spectral measure.
Mathematics Subject Classification: 47B15, 46A13, 46C05.
- G. Allan, On a class of locally convex algebras, Proc. London Math. Soc. 15 (1965), 399-421.
- C. Apostol, \(b^*\)-Algebras and their representations, J. London Math. Soc. 33 (1971), 30-38.
- J.B. Conway, A Course in Operator Theory, Amer. Math. Soc., 2000.
- A. Gheondea, On locally Hilbert spaces, Opuscula Math. 36 (2016), 735-747.
- A. Gheondea, Operator models for locally Hilbert \(C^*\)-modules, Operators and Matrices 11 (2017), 639-667.
- A. Inoue, Locally \(C^*\)-algebras, Mem. Fac. Sci. Kyushu Univ. Ser. A 25 (1971), 197-235.
- R.V. Kadison, J.R. Ringrose, Fundamentals of the Theory of Operator Algebras, Volume I: Elementary Theory, Graduate Studies in Mathematics, vol. 15, Amer. Math. Soc., 1997.
- A. Mallios, Hermitian K-theory over topological \(*\)-algebras, J. Math. Anal. Appl. 106 (1985), 454-539.
- N.C. Phillips, Inverse limits of \(C^*\)-algebras, J. Operator Theory 19 (1988), 159-195.
- K. Schmüdgen, Über \(LMC^*\)-Algebren, Math. Nachr. 68 (1975), 167-182.
- Z. Sebestyen, Every \(C^*\)-seminorm is automatically submultiplicative, Period. Math. Hun. 10 (1979), 1-8.
- Ş. Strătilă, L. Zsidó, Lectures on von Neumann Algebras, Editura Academiei, Bucureşti, 1979.
- J.L. Taylor, Notes on Locally Convex Topological Vector Spaces, Lecture Notes, University of Utah, 1995.
- D. Voiculescu, Dual algebraic structures on operator algebras related to free products, J. Operator Theory 17 (1987), 85-98.
- Aurelian Gheondea
- Bilkent University, Department of Mathematics, 06800 Bilkent, Ankara, Turkey
- Institutul de Matematică al Academiei Române, C.P., 1-764, 014700 Bucuresti, România
- Communicated by P.A. Cojuhari.
- Received: 2018-02-23.
- Revised: 2018-05-14.
- Accepted: 2018-05-15.
- Published online: 2018-06-12.