6 papers
Linear maps which are anti-derivable at zero
Doha Adel Abulhamil, Fatmah B. Jamjoom, Antonio M. Peralta
Let be a bounded linear operator, where is a C-algebra, and denotes an essential Banach -bimodule. We prove that the following statements are equivalent:…
Inner ideals, compact tripotents and Čebyšëv subtriples of JB-triples and C-algebras
Fatmah B. Jamjoom, Antonio M. Peralta, Akhlaq A. Siddiqui +1
The aim of this note is to study Čebyšëv JB-subtriples of general JB-triples. It is established that if is a non-zero Čebyšëv JB-subtriple of a JB-triple , t…
Quadratic Conorm and extremally rich JB*-triples
Fatmah B. Jamjoom, Antonio M. Peralta, Akhlaq A. Siddiqui +1
We introduce and study the class of extremally rich JB-triples. We establish new results to determine the distance from an element in an extremally rich JB-triple t…
Cebysev subspaces of JBW*-triples
Fatmah B. Jamjoom, Antonio M. Peralta, Akhlaq A. Siddiqui +1
We describe the one-dimensional Čebyšëv subspaces of a JBW-triple by showing that for a non-zero element in , is a Čebyšëv subspace of if, and onl…
Jordan weak amenability and orthogonal forms on JB*-algebras
Fatmah B. Jamjoom, Antonio M. Peralta, Akhlaq A. Siddiqui
We prove the existence of a linear isometric correspondence between the Banach space of all symmetric orthogonal forms on a JB-algebra and the Banach space of all…
Approximation and convex decomposition by extremals and the -function in JBW*-triples
Fatmah B. Jamjoom, Antonio M. Peralta, Akhlaq A. Siddiqui +1
We establish new estimates to compute the -function of Aron and Lohman on the unit ball of a JB-triple. It is established that for every Brown-Pedersen quasi-invertible elem…