Octonions are an eight-dimensional number system that are non-commutative and non-associative, meaning the order of multiplication matters, and grouping of multiplications can change the result; however, they are considered "alternative" which means they satisfy a weaker form of associativity, and are also power associative; they are considered the largest normed division algebra over real numbers, making them an extension of complex numbers and quaternions.
Key properties of octonions:
Key properties of octonions:
Dimensionality:Eight dimensions, making them a higher dimensional extension of quaternions.
Non-associativity:Unlike real numbers, complex numbers, and quaternions, the order of multiplication in octonions can affect the result.Non-commutativity:Multiplication is not commutative, meaning a * b is not necessarily equal to b * a.
Alternative property:While not fully associative, octonions satisfy the alternative property, which means that for any three octonions a, b, and c, the following holds: a(ba) = (ab)a and a(aa) = (aa)a.Power associative:Raising an octonion to a power is associative.
Normed division algebra:Octonions form a normed division algebra, meaning every non-zero octonion has a multiplicative inverse.
Cayley-Dickson construction:Octonions can be constructed using the Cayley-Dickson process, which is also used to build quaternions from complex numbers.
C. elegans is remarkable in that every worm has the same exact number of cells: 959 in the adult hermaphrodite (not counting the cells that will become eggs or sperm). 302 of these cells are neurons. Researchers in Brenner's group created two first-of-their-kind resources documenting the details of this biology.
from Wikipedia:
In mathematics, any Lagrangian system generally admits gauge symmetries, though it may happen that they are trivial. In theoretical physics, the notion of gauge symmetries depending on parameter functions is a cornerstone of contemporary field theory.
A gauge symmetry of a Lagrangian L is defined as a differential operator on some vector bundle E taking its values in the linear space of (variational or exact) symmetries of L. Therefore, a gauge symmetry of L depends on sections of E and their partial derivatives.[1] For instance, this is the case of gauge symmetries in classical field theory.[2] Yang–Mills gauge theory and gauge gravitation theory exemplify classical field theories with gauge symmetries.[3]
Gauge symmetries possess the following two peculiarities.1) Being Lagrangian symmetries, gauge symmetries of a Lagrangian satisfy Noether's first theorem, but the corresponding conserved current Jμ takes a particular superpotential form Jμ=Wμ+dνUνμ where the first term Wμ vanishes on solutions of the Euler–Lagrange equations and the second one is a boundary term, where Uνμ is called a superpotential.[4]
2) In accordance with Noether's second theorem, there is one-to-one correspondence between the gauge symmetries of a Lagrangian and the Noether identities which the Euler–Lagrange operator satisfies. Consequently, gauge symmetries characterize the degeneracy of a Lagrangian system.[5]Note that, in quantum field theory, a generating functional may fail to be invariant under gauge transformations, and gauge symmetries are replaced with the
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