PhyslibAlpha.AlgebraicFramework.JordanOrderUnit.JB.GeneratedByOne.Inherited
The inherited JB structure on a closed one-generator algebra
The closed algebra generated by one element is not merely a complete commutative normed algebra. It inherits the ambient order, order unit, square positivity, and JB square-norm law. This is the proper abstract input for the real Gelfand theorem needed by the Jordan continuous functional calculus: it retains the order information that distinguishes a formally real JB algebra from an arbitrary real uniform Banach algebra.
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is a normed Jordan algebra
Let be a normed Jordan algebra and let . The norm-closed Jordan subalgebra generated by the identity element and is a normed Jordan algebra. It inherits the norm, addition, scalar multiplication, and the Jordan product from the ambient algebra . Furthermore, while the multiplication in is generally non-associative, the multiplication restricted to is associative.
is nontrivial is nontrivial
Let be a nontrivial normed Jordan algebra. For any element , the norm-closed Jordan subalgebra generated by the identity and is also nontrivial.
The identity element of has norm
Let be a nontrivial normed Jordan algebra and let . In the norm-closed Jordan subalgebra generated by the identity element and , the norm of the identity element is equal to , i.e., .
is a JB algebra
Let be a JB algebra and let . The norm-closed Jordan subalgebra (also denoted as ) generated by the identity element and is itself a JB algebra.
Positive real scalars preserve the order on
In the norm-closed Jordan subalgebra generated by the identity and an element of a normed Jordan algebra, scalar multiplication by non-negative real numbers preserves the partial order. That is, for any such that and any elements , if , then .
is an order unit for
In a JB algebra , for any element , the identity element is an order unit for the norm-closed Jordan subalgebra generated by and . This means that for every element , there exists a real number such that .
is an Archimedean order unit space
Let be a JB algebra and let . The norm-closed Jordan subalgebra generated by the identity element and is an Archimedean order unit space. This implies that the identity is an order unit for and the partial order inherited by satisfies the Archimedean property.
is a Jordan Order Unit Algebra
Let be a JB algebra and . The norm-closed Jordan subalgebra generated by the identity element and is a Jordan order unit algebra. This means that is a Jordan algebra where the identity element acts as an order unit and the square of any element is non-negative ().
is a JB-order unit space
Let be a JB algebra and let . The norm-closed Jordan subalgebra generated by the identity element and is a JB-order unit space. This signifies that inherits the compatibility between the norm and the order structure from the ambient algebra, where the norm is the order unit norm and the Jordan-specific norm-order laws are satisfied.
