DifferentialGeometry/Tensor/ConjugateSpinor - Maple Help
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Tensor[ConjugateSpinor] - calculate the complex conjugate of a spinor

Calling Sequences

     ConjugateSpinor(S, ConjCoord)

Parameters

   S         - a spinor

   ConjCoord - (optional) keyword argument conjugatecoordinates = C, where C is a list of lists specifying conjugate coordinates

 

Description

Examples

See Also

Description

• 

The command ConjugateSpinor(S) calculates the complex conjugate of an arbitrary spinor S.

• 

For spinors with real parameters, the assuming command of Maple can be used to properly calculate the complex conjugates.

• 

This command is part of the DifferentialGeometry:-Tensor package, and so can be used in the form ConjugateSpinor(...) only after executing the commands with(DifferentialGeometry); with(Tensor) in that order.  It can always be used in the long form DifferentialGeometry:-Tensor:-ConjugateSpinor.

Examples

> 

with⁡DifferentialGeometry:with⁡Tensor:

 

Example 1.

First create a vector bundle E→M with base coordinates x,y,z,t and fiber coordinates z1,z2,w1,w2. For spinor applications, it is tacitly assumed that z1,z2 are complex coordinates with complex conjugates w1,w2.

> 

DGsetup⁡x,y,z,t,z1,z2,w1,w2,E

frame name: E

(2.1)

 

Define spinors S1 and S2 and calculate their complex conjugates.

E > 

S1≔D_z1

S1:=D_z1

(2.2)
E > 

ConjugateSpinor⁡S1

D_w1

(2.3)
E > 

S2≔dw1+3⁢I⁢dw2

S2:=dw1+3⁢I⁢dw2

(2.4)
E > 

ConjugateSpinor⁡S2

dz1−3⁢I⁢dz2

(2.5)

 

Example 2.

The two type 1,1 Kronecker delta spinors are complex conjugates of each other.

E > 

S3≔KroneckerDeltaSpinor⁡spinor

S3:=D_z1⁢dz1+D_z2⁢dz2

(2.6)
E > 

S4≔KroneckerDeltaSpinor⁡barspinor

S4:=D_w1⁢dw1+D_w2⁢dw2

(2.7)
E > 

ConjugateSpinor⁡S3&minusS4

0⁢D_z1⁢dz1

(2.8)

 

Example 3.

The soldering form is always a Hermitian spinor.  To check this calculate, first define the solder form σ, then conjugate σ and interchange the 2nd and 3rd indices.  The result is the original solder form σ.

E > 

F≔D_t,D_x,D_y,D_z:

E > 

σ≔SolderForm⁡F

σ≔22⁢dx⁢D_z1⁢D_w2+22⁢dx⁢D_z2⁢D_w1−I2⁢2⁢dy⁢D_z1⁢D_w2+I2⁢2⁢dy⁢D_z2⁢D_w1+22⁢dz⁢D_z1⁢D_w1−22⁢dz⁢D_z2⁢D_w2+22⁢dt⁢D_z1⁢D_w1+22⁢dt⁢D_z2⁢D_w2

(2.9)
E > 

bar_sigma≔ConjugateSpinor⁡σ

bar_sigma≔22⁢dx⁢D_w1⁢D_z2+22⁢dx⁢D_w2⁢D_z1+I2⁢2⁢dy⁢D_w1⁢D_z2−I2⁢2⁢dy⁢D_w2⁢D_z1+22⁢dz⁢D_w1⁢D_z1−22⁢dz⁢D_w2⁢D_z2+22⁢dt⁢D_w1⁢D_z1+22⁢dt⁢D_w2⁢D_z2

(2.10)
E > 

σ&minusRearrangeIndices⁡bar_sigma,2,3

0⁢dx⁢D_z1⁢D_z1

(2.11)

 

Example 4.

Use the Maple assuming command to simplify the complex conjugate of a spinor-tensor containing a real parameter α.

E > 

S5≔evalDG⁡α⁢D_t&tD_w1+xα⁢D_z&tD_w2

S5≔xα⁢D_z⁢D_w2+α⁢D_t⁢D_w1

(2.12)
E > 

S6≔ConjugateSpinor⁡S5assumingα::real

S6≔xα⁢D_z⁢D_z2+α⁢D_t⁢D_z1

(2.13)

 

Example 6.

In some applications complex coordinates on the base space are used. Suppose, for example, that z and t are real coordinates and that u is a complex coordinate with complex conjugate v.

M > 

DGsetup⁡u,v,z,t,z1,z2,w1,w2,N

frame name: N

(2.14)
N > 

S7≔evalDG⁡v⁢D_z1&tdz2+t⁢u⁢D_z2&tdz1

S7≔v⁢D_z1⁢dz2+t⁢u⁢D_z2⁢dz1

(2.15)

 

Use the keyword argument conjugatecoordinates to specify that the conjugate of u is v (and the conjugate of v is u).

N > 

ConjugateSpinor⁡S7,conjugatecoordinates=u,v

u⁢D_w1⁢dw2+t⁢v⁢D_w2⁢dw1

(2.16)
N > 

S8≔evalDG⁡α⁢D_u&tdz2

S8≔α⁢D_u⁢dz2

(2.17)
N > 

ConjugateSpinor⁡S8,conjugatecoordinates=u,vassumingα::real

α⁢D_v⁢dw2

(2.18)

See Also

DifferentialGeometry, Tensor, assuming, DGmap, KroneckerDeltaSpinor, RearrangeIndices, SolderForm