PhyslibAlpha.AlgebraicFramework.Algebra.NuclearInvolution
Nuclear involutions
A star involution on an alternative algebra whose symmetric elements are nuclear (associate trivially with everything) — the coordinate-algebra interface a `*`-alternative division algebra like the octonions needs to support an exceptional Albert Jordan algebra of Hermitian matrices over it. Independent of Jordan order, norms, CFC, and JBW normality.
Key definitions and results
- `IsNuclear`, `IsNuclearInvolution` - `nuclear_slip_left`/`_mid`/`_last`/`_last_right` : a nuclear element slips through the associator. - `assoc_star_first`/`_mid`/`_last` : the associator is alternating in sign under `star`. - `nuclear_comm_associator` : a nuclear element commutes with any associator.
10 declarations
Nuclearity of an element ()
An element in an algebra is nuclear if it associates trivially in every slot. Specifically, for all , the associator satisfies , , and .
A nuclear element slips through the left of the associator:
In an algebra , if is a nuclear element—meaning that for all , the associator satisfies —then for any elements , the associator satisfies the identity .
for nuclear
Let be an algebra. An element is said to be nuclear if it associates trivially in every position, meaning that for all , the associator satisfies , , and . For any such nuclear element and any elements , the identity holds.
for nuclear
Let be an algebra. Suppose is a nuclear element, meaning it associates trivially in every slot (i.e., for all ). For any elements , the associator satisfies the identity , where .
for nuclear
Let be an algebra. If is a nuclear element—meaning that for all , the associator satisfies —then for any elements , the associator satisfies the identity .
is Nuclear
Let be an alternative algebra equipped with a star involution denoted by . For any element , the sum is nuclear. An element is defined as nuclear if it associates trivially with all elements in the sense that the associator satisfies , , and .
In an alternative algebra equipped with a star involution, let denote the associator of elements . For any elements , the associator of the star of with and is the negative of the associator of : where denotes the star involution applied to .
Let be a -alternative algebra. For any elements , the associator satisfies the identity , where denotes the star involution of .
In an alternative algebra equipped with a star involution , for any elements , the associator satisfies the identity .
Nuclear Elements Commute with the Associator
Let be an algebra and be a nuclear element, meaning that for all , the associator satisfies , , and . Then for any , the element commutes with the associator of , such that .
