On Essential Numerical Range and Davis-Wielandt Shell of Hilbert Space Operators
Abstract: Let the numerical range of the operator T be denoted by W (T), the essential numerical range by We (T) and the Davis-Wielandt shell by DW (T). We discuss the equality of the essential numerical range and the numerical range of the operator T in a complex infinite dimensional Hilbert space H. The results obtained are used to study the instance when the essential numerical range can replace the numerical range in the Davis-Wielandt shell.
Keywords: Numerical range, Essential numerical range, Davis-Wielandt shell
How to Cite?: D. O. Owego, N. B. Okelo, Omolo Ongati, "On Essential Numerical Range and Davis-Wielandt Shell of Hilbert Space Operators", Volume 8 Issue 1, January 2019, International Journal of Science and Research (IJSR), Pages: 836-838, https://www.ijsr.net/getabstract.php?paperid=ART20179883, DOI: https://dx.doi.org/10.21275/ART20179883