Physics[GrassmannParity] - compute the Grassmannian parity, as 0, 1 or undefined, according to whether an expression is commutative, anticommutative or noncommutative
Calling Sequence
GrassmannParity(expression)
Parameters
expression
-
algebraic expression, or relation between them, or a set or list of them
Description
The GrassmannParity command computes the Grassmannian parity of expression, that is, 0, 1 or undefined, according to whether expression is commutative, anticommutative or noncommutative. In this sense, the parity here is equivalent to the type.
Examples
with⁡Physics:
Setup⁡mathematicalnotation=true
mathematicalnotation=true
Set theta as an anticommutative prefix (see Setup)
Setup⁡anticommutativepre=θ
* Partial match of 'anticommutativepre' against keyword 'anticommutativeprefix'
_______________________________________________________
anticommutativeprefix=θ
a⁢θ1⁢θ2+b
The parity of (3) is 0 despite the presence of anticommutative variables: a product of two of them is overall commutative
GrassmannParity⁡
0
A commutative function of commutative and anticommutative variables: its parity is zero
F⁡x,y,θ1,θ2
A taylor expansion as well as an exact expansion for it respectively performed with Gtaylor and ToFieldComponents
Gtaylor⁡,θ1
F⁡x,y,0,θ2+D3⁡F⁡x,y,0,θ2⁢θ1
ToFieldComponents⁡
_F1⁡x,y−θ1⁢_Q1⁡x,y−θ2⁢_Q2⁡x,y+_F2⁡x,y⁢θ1⁢θ2
Note that the expansion performed with Gtaylor does not preserve the parity of (5) while the one performed with ToFieldComponents does:
undefined
The coefficient of order zero of both expansions preserves the parity; the difference appears with respect to the coefficient of order 1
Coefficients⁡=,θ1,0
F⁡x,y,0,θ2=_F1⁡x,y−θ2⁢_Q2⁡x,y
map⁡GrassmannParity,
0=0
Coefficients⁡=,θ1,1
D3⁡F⁡x,y,0,θ2=−_Q1⁡x,y+_F2⁡x,y⁢θ2
0=1
To understand this difference between the Taylor and the exact expansions performed with Gtaylor and ToFieldComponents see the expansion's definitions in the respective help pages
See Also
anticommutative, Coefficients, commutative, Physics, Physics conventions, Physics examples, Physics Updates, Tensors - a complete guide, Mini-Course Computer Algebra for Physicists, relation, series, Setup, ToFieldComponents
Compatibility
The Physics[GrassmannParity] command was introduced in Maple 16.
For more information on Maple 16 changes, see Updates in Maple 16.
Download Help Document