In abstract algebra, sedenions form a 16-dimensional algebra over the reals. Abstract algebra is the subject area of Mathematics that studies Algebraic structures such as groups, rings, fields, modules In Mathematics, the dimension of a Vector space V is the cardinality (i In Mathematics, an algebra over a field K, or a K -algebra, is a Vector space A over K equipped with In Mathematics, the real numbers may be described informally in several different ways The set of sedenions is denoted as
. Two types are currently known:
Contents |
Like (Cayley-Dickson) octonions, multiplication of Cayley-Dickson sedenions is neither commutative nor associative. In Mathematics, the octonions are a nonassociative extension of the Quaternions Their 8-dimensional Normed division algebra over the Real In Mathematics, commutativity is the ability to change the order of something without changing the end result In Mathematics, associativity is a property that a Binary operation can have But in contrast to the octonions, the sedenions do not even have the property of being alternative. In Abstract algebra, an alternative algebra is an algebra in which multiplication need not be Associative, only alternative. They do, however, have the property of power associativity. In Abstract algebra, power associativity is a weak form of Associativity.
Every sedenion is a real linear combination of the unit sedenions 1, e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12, e13, e14 and e15, which form a basis of the vector space of sedenions. In Mathematics, linear combinations are a concept central to Linear algebra and related fields of mathematics In Mathematics, a vector space (or linear space) is a collection of objects (called vectors) that informally speaking may be scaled and added
The sedenions have a multiplicative identity element 1 and multiplicative inverses, but they are not a division algebra. In Mathematics, an identity element (or neutral element) is a special type of element of a set with respect to a Binary operation on that In the field of Mathematics called Abstract algebra, a division algebra is roughly speaking an Algebra over a field in which division is possible This is because they have zero divisors; this means that two non-zero numbers can be multiplied to obtain a zero result: a trivial example is (e3 + e10)*(e6 - e15). In Abstract algebra, a nonzero element a of a ring is a left zero divisor if there exists a nonzero b such that ab = 0 All hypercomplex number systems based on the Cayley-Dickson construction from sedenions on contain zero divisors.
The multiplication table of these unit sedenions follows:
| × | 1 | e1 | e2 | e3 | e4 | e5 | e6 | e7 | e8 | e9 | e10 | e11 | e12 | e13 | e14 | e15 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | e1 | e2 | e3 | e4 | e5 | e6 | e7 | e8 | e9 | e10 | e11 | e12 | e13 | e14 | e15 |
| e1 | e1 | -1 | e3 | -e2 | e5 | -e4 | -e7 | e6 | e9 | -e8 | -e11 | e10 | -e13 | e12 | e15 | -e14 |
| e2 | e2 | -e3 | -1 | e1 | e6 | e7 | -e4 | -e5 | e10 | e11 | -e8 | -e9 | -e14 | -e15 | e12 | e13 |
| e3 | e3 | e2 | -e1 | -1 | e7 | -e6 | e5 | -e4 | e11 | -e10 | e9 | -e8 | -e15 | e14 | -e13 | e12 |
| e4 | e4 | -e5 | -e6 | -e7 | -1 | e1 | e2 | e3 | e12 | e13 | e14 | e15 | -e8 | -e9 | -e10 | -e11 |
| e5 | e5 | e4 | -e7 | e6 | -e1 | -1 | -e3 | e2 | e13 | -e12 | e15 | -e14 | e9 | -e8 | e11 | -e10 |
| e6 | e6 | e7 | e4 | -e5 | -e2 | e3 | -1 | -e1 | e14 | -e15 | -e12 | e13 | e10 | -e11 | -e8 | e9 |
| e7 | e7 | -e6 | e5 | e4 | -e3 | -e2 | e1 | -1 | e15 | e14 | -e13 | -e12 | e11 | e10 | -e9 | -e8 |
| e8 | e8 | -e9 | -e10 | -e11 | -e12 | -e13 | -e14 | -e15 | -1 | e1 | e2 | e3 | e4 | e5 | e6 | e7 |
| e9 | e9 | e8 | -e11 | e10 | -e13 | e12 | e15 | -e14 | -e1 | -1 | -e3 | e2 | -e5 | e4 | e7 | -e6 |
| e10 | e10 | e11 | e8 | -e9 | -e14 | -e15 | e12 | e13 | -e2 | e3 | -1 | -e1 | -e6 | -e7 | e4 | e5 |
| e11 | e11 | -e10 | e9 | e8 | -e15 | e14 | -e13 | e12 | -e3 | -e2 | e1 | -1 | -e7 | e6 | -e5 | e4 |
| e12 | e12 | e13 | e14 | e15 | e8 | -e9 | -e10 | -e11 | -e4 | e5 | e6 | e7 | -1 | -e1 | -e2 | -e3 |
| e13 | e13 | -e12 | e15 | -e14 | e9 | e8 | e11 | -e10 | -e5 | -e4 | e7 | -e6 | e1 | -1 | e3 | -e2 |
| e14 | e14 | -e15 | -e12 | e13 | e10 | -e11 | e8 | e9 | -e6 | -e7 | -e4 | e5 | e2 | -e3 | -1 | e1 |
| e15 | e15 | e14 | -e13 | -e12 | e11 | e10 | -e9 | e8 | -e7 | e6 | -e5 | -e4 | e3 | e2 | -e1 | -1 |
In contrast to Cayley-Dickson sedenions, which are built on one and 15 roots of negative one, conic sedenions are built on 8 square roots each of positive and negative one. They share non-commutativity and non-associativity with Cayley-Dickson sedenion ("circular sedenion") arithmetic, however, conic sedenions are modular, alternative, and flexible. With the exception of its nilpotents, zero divisors, and zero itself, the arithmetic is closed with respect to the power-of and logarithm operations. In Mathematics, an element x of a ring R is called nilpotent if there exists some positive Integer n such that In Abstract algebra, a nonzero element a of a ring is a left zero divisor if there exists a nonzero b such that ab = 0 Conic sedenions are not power-associative.
For detailed information and isomorphic subalgebras see Musean hypernumber. Musean hypernumbers are an algebraic concept envisioned by Charles A