Akhlaq A. Siddiqui
Address.
Department of Mathematics, The University of Lahore,1Km Raiwind
Road, Lahore, Pakistan
E-mail: saakhlaq@yahoo.com
Abstract.
By investigating the extent to which
variation in the coefficients of a convex combination of unitaries in a unital $JB^{*}$-algebra permits that combination to be expressed as convex combination of fewer unitaries
of the same
algebra, we generalise various results of R.\ V.\ Kadison and G.\ K.\ Pedersen.
In the
sequel, we shall give a couple
of characterisations of $JB^{*}$-algebras of $tsr\ 1$.
AMSclassification. 17C65, 46H70, 46L70
Keywords. $C^{*}$-algebras, Jordan algebras, $JB^{*}$-algebras, unitary isotopes.