On the Fundamental Spinor Matrices of Real Quaternions
TÜLAY ERİŞİR1, EMRAH YILDIRIM2
1Department of Mathematics, Faculty of Arts and Sciences,
Erzincan Binali Yıldırım University,
24002, Erzincan,
TURKEY
2Department of Mathematics, Graduate School of Natural and Applied Sciences,
Erzincan Binali Yıldırım University,
24002, Erzincan,
TURKEY
Abstract: - In this study, the real quaternions and spinors are studied. The motivation of this study is to express
the Hamilton matrices of real quaternions more shortly and elegantly, namely spinors. Therefore, firstly, two
transformations between real quaternions and spinors are defined. These transformations are defined for two
different spinor matrices corresponding to the left and right Hamilton matrices since the quaternion product is
not commutative. Thus, the fundamental spinor matrix corresponding to the fundamental matrix of real
quaternions is obtained and some properties are given for these spinor matrices. Finally, the eigenvalues and
eigenvectors of the fundamental spinor matrix are obtained.
Key-Words: - Spinors, Quaternions, Hamilton matrices, Spinor metrices
Received: July 11, 2023. Revised: October 8, 2023. Accepted: October 25, 2023. Published: November 15, 2023.
1 Introduction
Quaternions were obtained by generalizing complex
numbers to develop a new number system. The
studies, [1], [2], [3], introduced a new multiplication
operation with this into vector algebra and obtained
the quaternions that may be possible in its division.
Moreover, real quaternions have no commutative
property. Quaternion product is a combination of the
scalar multiplication, the Euclidean inner product,
and the vector product. Thus, the set of real
quaternions is a two-dimensional vector space on
the set of complex numbers and a four-dimensional
vector space on the set of real numbers. Today, the
matrices are used in many branches of science and
have a great importance. For this reason, the
relationship of matrices with quaternions has
attracted much attention. Since the quaternion
product is not commutative, the product of the right
and the product of the left with another quaternion
are not equal. This is paired matrices with
44x
the
type quaternions with two separate multiplications,
thanks to a transformation. Thus, the left product
represents the left matrix representation of a
quaternion, and the right product represents the right
matrix representation of a quaternion. These matrix
representations are called Hamilton matrices
corresponding to the Hamilton operators of the real
quaternions. On the other hand, a lot of studies have
been done about matrices whose elements are
composed of quaternions. The studies on
quaternions date back to 1936. The study, [4], gave
the concept of similarity for matrices whose
elements are real quaternions. Later, the study, [5],
made a study on the eigenvalue and diagonalization
of quaternion matrices. In addition, the study, [6],
showed that every quaternion matrix, including a
square, has a characteristic root, and in addition,
similar matrices have the same characteristic root.
The study, [7], gave one of the most important
studies on quaternion matrices.
With the introduction of Hamilton in 1843,
quaternions have found many uses until today.
Quaternions, which provide great convenience in
engineering fields apart from geometry and algebra,
are also of great importance in the mathematics of
today's technology. It is also used in computer
graphics, physics, mechanics, kinematics, computer
games, animations, and digital imaging. Quaternions
are of great importance in geometry, especially in
the representation of the rotation of objects in 3-
dimensional space. Quaternions also have many
uses in physics. The use of complex numbers in
mechanical and electrical applications, especially in
circuit analysis, limits the applications since they are
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two-dimensional. In 3-dimensional applications, in
cases where vectors are insufficient in some
applications, quaternions add a fourth dimension to
applications, providing great convenience. The most
important of the fields where quaternions find
applications in physics is Einstein's special and
general relativity theories. Quaternions are used to
describe electron spin in quantum mechanics.
Quantum operators operating on a spinor can be
represented by quaternions considering the
relationship of
22x
matrices with quaternions. With
the help of this approach, B. L. Van der Waerdan
developed the mathematical formula of spinors in
1930. Pauli in 1927 and Dirac in 1938 demonstrated
spinor equations to describe the electron spin
physically.
The introduction of spinors is one of the most
difficult topics in quantum mechanics. Even if spin-
1/2 is considered, some fundamental aspects of
spinors, such as the effects of rotation on spinors,
turn out to be difficult to explain. According to
physicists, spinors are multilinear transformations.
Thanks to this feature, spinors are mathematical
entities somewhat like tensors and allow a more
general treatment of the notion of invariance under
rotation and Lorentz boosts. For mathematicians,
spinors are vectorial objects and their multilinear
features do not play any role. In addition, spinors
have one index. In discussing vectors and tensors,
there are two ways, in which we can proceed: the
geometrical and analytical. To use the geometrical
approach, we describe each kind of quantity in
terms of its magnitudes and directions. In the
analytical treatment, we use components. The study,
[8], while investigating linear representations of
simple groups developed the most general
mathematical form of spinors. In geometric terms,
the study, [9], introduced spinors. The study, [9],
developed the spinor theory geometrically by giving
only the geometric definition of spinors. Then, the
spinor formulation of curves is given by the study,
[10], considering Frenet vectors of curves in three-
dimensional Euclidean space. That study is an
important study for the relationship between curve
theory and spinors in differential geometry. Pauli
matrices, which are a basis
2SU
, and spinor
algebra, which have two complex components,
provide a nice representation of rotations in three-
dimensional real space. In this context, the study,
[11], established a new relationship between
quaternions and spinors and expressed quaternion
kinematics with spinors. In the study, [11], a one-to-
one and linear relationship was established between
spinors and real quaternions, and spinor formulation
and thus spinor kinematics of spins represented by
real quaternions were obtained. On the other hand,
the study, [12], investigated quaternions and spinors
in quantum mechanics by establishing a relationship
between
3SO
and
. The study, [13],
obtained a main expression of quaternions with
matrices by
22x
by considering the isomorphism
between real quaternions and spinors. Moreover, the
properties of the fundamental real matrix associated
with a quaternion were investigated and a frequently
considered quaternion equation was examined, from
which the nth power of a quaternion can be
determined, [14]. Therefore, the spinor
representations in Euclidean 3-space were studied
using different frames such as Darboux, Bishop, q-
frame, [15], [16], [17]. The study, [18], obtained the
Frenet spinor equations of Lie groups in Euclidean
space with a bi-invariant metric and gave some
special situations for these Lie groups with three-
dimensional. Later, studies on spinors in this field of
differential geometry focused on special curves. The
study, [19], revealed the spinor representations of
the involute-evolute curves and the relationship
between these spinors. Then, Bertrand curves were
represented by spinors in the complex plane, and the
study, [20], proved the relationship between spinors
corresponding to these Bertrand curves. After that,
the successor curve couple corresponded to two
different spinors, and geometric interpretations were
derived, [21]. In addition to that, the spinor
representations of some curve pairs selected in
Minkowski space were obtained, [22], [23], [24],
[25]
The motivation of this study is to obtain a new
and easier matrix representation of the Hamilton
matrices corresponding to the Hamilton operators of
the real quaternions. For this, first, considering the
isomorphism between spinors and quaternions, the
spinor matrices corresponding to the right and left
Hamilton matrices of real quaternions have been
created. Since the quaternion product is not
commutative, two separate spinor matrices
corresponding to these Hamilton matrices have been
formed. These matrices have been called the left and
right Hamilton spinor matrices. Moreover, some
properties of these right and left Hamilton spinor
matrices have been given. Consequently,
considering the left Hamilton spinor matrix as the
fundamental spinor matrix some theorems and
results about the eigenvalues and eigenvectors of the
fundamental spinor matrix have been obtained.
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2 Preliminaries
2.1 Quaternions and Spinors
In this section, we give some propositions and
theorems about the real quaternions and spinors. Let
0 1 2 3
q q q q q i j k
be real quaternions in the set
of real quaternions
H
where
0 1 2 3
, , ,q q q q
and
3
,,i j k
such that
1= = = ii jj kk
,
=ij ji k
,
==jk kj i
,
==ki ik j
. In this
case, the set of real quaternions
H
can be
expressed
3
0 1 2 3 0 1 2 3
{ , , , , , , , }.q q q q q q q q q q i j k i j kH R R
Now, we assume that the real quaternion
0 1 2 3
q q q q q i j k
is
qq
qSV
where the
scalar part of
q
is
0q
Sq
and the vector part of
q
is
1 2 3
qq q q V i j k
, [26]. Let any two real
quaternions be
pp
pSV
and
qq
qS VH
.
Therefore, the addition of these real quaternions is
expressed
p p q q p q p q
p q S S S S V V V V
where
: H H H
. Moreover, the scalar
product of the real quaternion
qq
qS VH
is
written by
q q q q
q S S
VV
where
R
and
:R H H
. Consequently, with the
aid of these operations, we say that the system
, , , ,.,HR
is a real vector space, briefly, this
space can be denoted by
H
where
p
S , , ,1 i j kH
and
dim 4H
, [26]. Assume
that any two real quaternions are
,
p p q q
p S q S VVH
. In this case, this
quaternion product is
,
p q p q p q q p p q
pq S S S S V V V V V V
where
,
and
are Euclidean scalar and vector
products in
3
E
. We know that the product of two
quaternions is a quaternion, the product of
quaternions has the properties of associative and
distributive. But the quaternion product is not
commutative. Thanks to these properties, the system
{ , , , ,., }HR
is an associative algebra, [26]. Let
any real quaternion be
qq
qS VH
. Therefore,
the conjugate of the quaternion
q
is expressed as
*qq
qSV
. On the other hand, the norm of the
real quaternion
q
is defined by
* 2222
0 1 2 3
()N q qq q q q q
. In this case, if
the norm of the quaternion
qH
is
( ) 1Nq
then,
this quaternion is called the unit quaternion. In
addition that, the inverse of the real quaternion
q
is
*
1
2()
q
qNq
where
0q
, [26].
On the other hand, assume that the real quaternion
qH
. Therefore, we can write this quaternion as
0 1 2 3 0 1 2 3
q q q q q q q q q i j k i i j
and we say that
1 2 1 0 1 2 2 3
,q z z z q q z q q j i iHC
is
isomorphic with
2
C
since the real quaternion
q
matches with the complex number
2
12
zzjC
,
[26], [27]. In addition to that, the real quaternion can
be written as
0 1 2 3 0 1 2 3 1 2 .q q q q q q q q q z z i j k i j ji
In this case,
H
has the basis
,1j
. Therefore, the
transformation
()
q
T p pq
is linear and the
2
matrix corresponding to this linear transformation is
0 1 2 3
2 3 0 1
q q q q
q q q q




ii
ii
,
[26]. The algebra of the real quaternions
H
contains infinite sub-algebras derived from bases
such as
, , ,......, , ,1 i 1 j 1 k
, [28]. Therefore,
the set of quaternions
H
can be written according
to many bases. Moreover, the study, [28], wrote the
real quaternion
q
as
0 1 2 3 0 2 1 3
q q q q q q q q q i j k j i j
with the aid of the basis
,1i
and obtained the
complex matrix
0 1 1 3
1 3 0 2
q q q q
q q q q




jj
jj
.
Assume that
33
C
is the complex vector space and
the vector
3
1 2 3
( , , )x x xx3
C
is isotropic vector
where
222
1 2 3 0xxx
. The set of the isotopic
vectors in the complex vector space
33
C
corresponds to a surface with two dimensional in
23
C
. If this surface with two dimensional is
parameterized by the complex numbers
1
and
2
then, the equations
,
22
1 1 2
x = -

22
2 1 2
x = ( + )

i
,
222
3 1 2
x =-

are provided where
i
is the complex
unit,
21i
and
12
,

C
. It can be easily seen
that every isotopic vector in the complex vector
space
33
C
corresponds to two vectors in
2
C
such
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that
12
( , )

and
12
( , )


. On the contrary, these
both vectors are given in this way in
2
C
correspond
to a single isotropic vector
x
. Cartan expressed that
the complex vector with two dimensional such that
1
2



is called as spinor, [9]. Moreover, the
study, [9], gave that the conjugate of the spinor
12
( , )
is
C
i
.
SO 3
, the group of
rotations about the origin in a three-dimensional real
vector space
3
R
, is homomorphic to
, the
group of unitary matrices with two dimensional
22
. The elements of group
SO 3
move vectors
in vector space
3
R
, while elements of group
move vectors with two complex
components, i.e. spinors, [10], [29], [30]. With the
aid of this homomorphism, the study, [31], paired an
isotropic vector with a spinor
1
2



. Now, we
assume that
is a vector whose Cartesian
components are the complex symmetric
22
matrices such that
1 2 3
1 0 0 0 1
,,
0 1 0 1 0

i
i
.
These matrices are produced in Pauli matrices
1 2 3
0 1 0 1 0
,,
1 0 0 0 1
P P P
i
i
with the
help of the matrix
01
10
C


, [31]. Therefore, the
isotropic vector
3
+abCi
can be written by any
spinor
such that
=t
+
abi
. In addition to that,
the real vector
3
cR
, orthogonal with the vectors
3
,ab R
, can be expressed
c
in terms of
the spinor
where
""
is the mate of the spinor
such that
C


, [31].
The study, [11], gave the relation between real
quaternions and spinors with the transformation
:fHS
such that
30
0 1 2 3
12
( ) ( ) qq
q f q f q q q q qq



i j k i
i
.
In addition, the study, [11], obtained that the
bijective transformation
f
provides the following
equations
i) ( ,
ii) ( ) ( ),
f q+ p)= f(q)+ f(p)
f q f q
R
for
,pqH
. Therefore, the transformation
f
is
linear.
2.2 The Hamilton Operators of Real
Quaternions
We assume that any real quaternion is
0 1 2 3
q q q q q i j k H
and the linear
transformation
h
is as
:h
p h p qp

HH
. (1)
In this case, we can write the matrix corresponding
to basis
, , , 1 i j k
0 1 2 3
1 0 3 2
2 3 0 1
3 2 1 0
()
q q q q
q q q q
Hq q q q q
q q q q






with the aid of the transformation
h
. Similarly,
with the aid of the linear transformation
( ):
.
hq
p h p pq

HH
(2)
Therefore, the matrix corresponding to the basis
, , , 1 i j k
can be obtained as
0 1 2 3
1 0 3 2
2 3 0 1
3 2 1 0
()
q q q q
q q q q
Hq q q q q
q q q q






according to the transformation
h
. Here, the
matrices
()Hq
and
()Hq
are called the left and
right Hamilton matrices corresponding to the
Hamilton operators
h
and
h
of the real
quaternion
q
, [27], [32]. On the other hand, we
suppose two real quaternion
0 1 2 3
p p p p p i j k
and
0 1 2 3
q q q q q i j k
. In this case, the matrix
form of the product
qp
of these real quaternions is
0 0 1 1 2 2 3 3
1 0 0 1 3 2 2 3
2 0 3 1 0 2 1 3
3 0 2 1 1 2 0 3
0 1 2 3 0
1 0 3 2 1
2 3 0 1 2
3 2 1 0 3
()
q p q p q p q p
q p q p q p q p
qp q p q p q p q p
q p q p q p q p
q q q q p
q q q q p H q P
q q q q p
q q q q p







.
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Similarly, the matrix form of the product
pq
of
these real quaternions is
0 0 1 1 2 2 3 3
1 0 0 1 3 2 2 3
2 0 3 1 0 2 1 3
3 0 2 1 1 2 0 3
0 1 2 3 0
1 0 3 2 1
2 3 0 1 2
3 2 1 0 3
()
q p q p q p q p
q p q p q p q p
pq q p q p q p q p
q p q p q p q p
q q q q p
q q q q p H q P
q q q q p
q q q q p







, [27].
Moreover, the representation
()Hq
of a quaternion
q
is well-known in algebra. Since
()Hq
plays a
crucial role in our subsequent considerations, we
call it as the fundamental matrix.
Theorem 2.1: Let any real quaternion be
qH
. In
this case, the Hamilton matrices
H
and
H
produced from the operators
h
and
h
are
orthogonal, [27].
Theorem 2.2: The product of Hamilton matrices
H
and
H
are commutative. Therefore, there is
equality
( ) ( ) ( ) ( )H q H p H p H q
, [27].
Theorem 2.3: Let any two real quaternions be
,pqH
and
R
. Hence, the Hamilton matrices
H
and
H
provide the following properties;
2()
i) p= q H (p)= H (q) H (p)= H (q)
ii) H (p+q)= H (p)+ H (q),
H (p+q)= H (p)+ H (q)
iii) H (pq)= H (p)H (q), H (pq)= H (q)H (p)
iv) H ( q )= H (q), H ( p)= H (q)
2
v) det H (q) = N (q), det H (q) = N q
vi)



1
1
1
1, ( ) 0
H (q )= H (q) ,
H (q )= H (q) N q

3 Main Theorems and Proofs
In this section, we establish a relationship between
quaternions and spinors and we give spinors
corresponding to real quaternions. Then, we express
the spinor matrices corresponding to Hamilton
matrices of real quaternions. In addition to that, we
calculate the eigenvalues and eigenvectors of these
spinor matrices, which we call Hamilton spinor
matrices, after giving some properties of these
matrices. Consequently, we obtain some
conclusions.
3.1 Spinor Representation of Real
Quaternions
Let
0 1 2 3
q q q q q i j k H
be an arbitrary real
quaternion where
0 1 2 3
, , ,q q q q
,
3
,,i j k
, and
H
is real quaternion space. In this case, we can
write the real quaternion
q
with regard to the basis
k,i
with left multiplication as
3 0 1 2
( ) ( )q q q q q iiki
(3)
where
==iji k
and since
21i
we can consider
that
i
is imaginer unit. Therefore, the quaternion
q
can be expressed in terms of two complex numbers
1 3 0 2 1 2
q q q q

iiC
. So, we can give the
following definition.
Definition 3.1: Let
0 1 2 3
q q q q q i j k
be a real
quaternion in
H
. In this case, the set of real
quaternions is defined by
1 2 1 3 0 2 1 2
,q q q q q
kiHCii
(4)
where ‘’ ‘’ is a complex conjugate.
As a result of Definition 3.1, according to the
expression given in equation (4) the following
transformation can be given.
Let the real quaternion be
q
written by in terms of
the spinor
. Therefore, we can give the
transformation between quaternions and spinors as
30
0 1 2 3
12
:
( ) ( )
f
qq
q f q f q q q q qq



i j k
HS
i
i
(5)
with aid of the equation (3), [11]. As is known, the
vector space
H
is isomorphic to the space
2
C
,
[33]. Therefore, the transformation
f
defined in
equation (5) is isomorphism.
Now, we give the following definition about the
conjugate of spinors based on the relationship
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between quaternions and spinors in the equation the
transformation
f
.
Definition 3.2: Suppose that the quaternion
0 1 2 3
q q q q q i j k H
matches the spinor
30
12
qq
qq




S
i
i
. In this case, the four different
definitions of conjugate for spinors;
i) The complex conjugate
of the spinor
1
2



S
corresponding to the real quaternion
qH
is defined by
1 3 0
12
2
.
qq
qq







i
i
ii) The spinor
*
corresponding to the quaternionic
conjugate
*
0 1 2 3
q q q q q i j k
of the real
quaternion
qH
is defined by
30
*1
12
2
.
qq
qq





i
i
iii) The spinor conjugate
of the spinor
S
by
given, [9], is defined by
21
12
03
21
01 .
10
qq
qq





 
 
i
ii
i
(6)
iv) The mate of the spinor
S
by given, [31], is
defined by
12
12
30
21
01
10
qq
qq







 
i
i
.
Therefore, the following corollaries can be given.
Corollary 3.1: Let
q
be an arbitrary real
quaternion and
be the spinor corresponding to
this quaternion
q
. There is the relationship

i
between the spinor conjugate and the mate of the
spinor
.
Corollary 3.2: Consider that the spinor
S
corresponds to the real quaternion
qH
. In this
case, the spinor equation of the norm of
q
is given
that
t t t t
N C C
i
where
01
10
C



.
Proof: Suppose that the spinor
S
corresponds
to the real quaternion
qH
. Therefore, we write
1
21
2
2222
1 1 2 2 0 1 2 3
01
10
()
tt
C
qqqqN


 

 


 

and
2222
0 1 2 3 ()
t
tt t t t t
C C C C C
qqqqN
i i i
where
01
10
C


.
3.2 Hamilton-Spinor Matrices
The quaternion product is not commutative in the
quaternion algebra therefore, the Hamilton matrices
corresponding to the right and left quaternion
products are different. In this case, in this section,
we obtain the spinor matrices for the right and left
Hamilton matrices, separately. Moreover, we call
these spinor matrices the left and right Hamilton
spinor matrices. Then, we give some properties and
theorems for these spinor matrices.
We know that the set of quaternions can be
written as in equation (4). In this case, the operator
in equation (1) is linear transformation therefore,
this linear transformation corresponds to a matrix.
Therefore, the following theorem can be given.
Theorem 3.3: Let
0 1 2 3
q q q q q i j k H
be
an arbitrary real quaternion written as
12
q

ki
where
1 3 0 2 1 2
,q q q q

 Cii
. Therefore,
the left Hamilton-spinor matrix corresponding to the
left Hamilton matrix of quaternion
qH
is given
by
0 3 2 1
2 1 0 3
.
L
q q q q
q q q q




ii
ii
(7)
Proof: Suppose that the real quaternion
0 1 2 3
q q q q q i j k H
is written as
12
.q

ki
In this case, if we consider Hamilton
operator in equation (1) then, we obtain
1 2 1 2
h
k k k i k k k i k
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(8)
and
1 2 2 1
h
i k i i i k k i k
(9)
where
11

kk
,
22

kk
,
11

ii
and
22

ii
. Therefore, we find that the matrix form
of the equations (8) and (9) is
0 3 2 1
2 1 0 3
L
q q q q
q q q q




ii
ii
.
This matrix
L
is called the left Hamilton spinor
matrix corresponding the left Hamilton matrix of
real quaternion
qH
. The proof is completed.
Moreover, since
()Hq
is the fundamental matrix
for the real quaternion
q
we can call the left
Hamilton spinor matrix
L
the fundamental spinor
matrix.
Corollary 3.4: For the fundamental spinor matrix
L
the statement
() L
q p H q P

is provided where
is the spinor corresponds to
real quaternion
p
with the aid of the transformation
f
, [11].
Now, for the right Hamilton spinor matrix, we need
to define a new transformation similar to the
equation (5). For this, we can write that the real
quaternion
q
with regard to the basis
k,i
as
3 0 1 2
( ) ( )q q q q q iiki
(10)
with right multiplication where
==iji k
.
Therefore, the quaternion
q
can be expressed in
terms of
1 3 0 2 1 2
,q q q q

iiC
. In this
case, the set of real quaternions can be defined by
1 2 1 3 0 2 1 2
,q q q q q
kiHCii
where ‘’ ‘’ is a complex conjugate. Moreover,
similar to the transformation
f
, with the aid of
equation (10) the transformation
*
f
can be given as
*
30
* 0 1 2 3 *
12
:
( ) ( ) .
f
qq
q f q f q q q q qq



i j k
HS
i
i
(11)
Theorem 3.5: Let the real quaternion
qH
be
1 2 1 2
q
k i k i
where
1 3 0
qq
i
and
2 1 2
qq
Ci
. The right Hamilton spinor matrix
of this quaternion is
0 3 2 1
2 1 0 3
.
R
q q q q
q q q q




ii
ii
(12)
Proof: Assume that the real quaternion
0 1 2 3
q q q q q i j k H
is
12
q

ki
. Then,
with the aid of the Hamilton operator in equation (2)
we can write
1 2 1 2
((h
k k k k i k )k k )i
and, similarly
1 2 2 1
((h
i i k i i k )k k )i
where
11

kk
,
22

kk
,
11

ii
and
22

ii
. Consequently, we get
0 3 2 1
2 1 0 3
R
q q q q
q q q q




ii
ii
.
Therefore, the matrix
R
is called the right
Hamilton spinor matrix corresponding to the left
Hamilton matrix of the real quaternion
q
.
Corollary 3.6: For the right Hamilton spinor matrix
we can write
*
() R
p q H q P

where
*
is the spinor corresponding to the real
quaternion
p
with the aid of the function
*
f
.
Now, we give the relationship between the Hamilton
spinor matrices
R
,
L
and the Pauli matrices.
Theorem 3.7: Let
0 1 2 3
q q q q q i j k H
be
any real quaternion and
R
and
L
be the left and
right Hamilton spinor matrices corresponding to the
real quaternion
q
. Therefore, these spinor matrices
can be written as
0 2 1 1 2 2 3 3Lq I q P q P q P
i i i
and
0 2 1 1 2 2 3 3Rq I q P q P q P
i i i
where
2
22
IC
is unit matrix with
22
and
2
1 2 3 2
,,P P P C
are Pauli matrices.
Proof: Let the left Hamilton spinor matrix be
L
.
Then, from the equation (7) we get
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1
2
1
2
3
10
1, 01
01
,10
0
,1
10
,.
01
L
i
L
j
L
k
L
for q I
for q i P
for q j P
for q k P












ii
i
ii
i
ii
Hence, we have
0 2 1 1 2 2 3 3Lq I q P q P q P
i i i
.
Similarly, for the right Hamilton spinor matrix in
equation (12) we obtain for
1q
1
2RI
, for
qi
1
i
RP
i
, for
qj
2
j
RP
i
and for
qk
3
k
RP
i
. Consequently, the equation
0 2 1 1 2 2 3 3Rq I q P q P q P
i i i
is found.
Theorem 3.8: Let any two real quaternions be
,pqH
and the left and right Hamilton spinor
matrices corresponding to these quaternions be
,
LR

and
,
LR

, respectively. Then, the
following statement is provided;
**
*
22
1 * 1
*
( ) , ( ) ,
) ( ) , ( ) ,
( ) , ( ) ,
1 , 1 ,
ˆ,,
( ) , ( ) .
L L L R R R
L L R R
L L R R
LR
LR
LR
L L L L R R R R
i) = + = +
ii = =
iii) = =
iv) I I
v) = P = P
vi) = =
  
 



 ii
where
,

R C1
and
2
2
0
0



C
.
Proof: Assume that
,
LR

and
,
LR

, are the left
and right Hamilton spinor matrices corresponding to
any two real quaternions
p
and
q
, respectively.
Therefore, we can give the proof.
i) Let
,

S
be two spinors corresponding to
the real quaternions
p
and
q
, respectively. Then,
with the aid of the transformation
f
in the equation
(5) we write
3 3 0 0
1 1 2 2
p q p q
p q p q




i
i
and the left Hamilton spinor matrix of the spinor

is obtained as
0 0 3 3 2 2 1 1
2 2 1 1 0 0 3 3
0 3 2 1 0 3 2 1
2 1 0 3 2 1 0 3
.
L
LL
p q p q p q p q
p q p q p q + p q
p p p p q q q q
p p p p q q q + q








ii
ii
i i i i
i i i i
Similarly, for the right Hamilton spinor matrix, the
proof is completed easily.
ii) We assume that
R
and the spinor
30
12
.
qq
qq

 



i
i
Then, we get the left Hamilton
spinor matrix of the spinor

0 3 2 1
2 1 0 3
0 3 2 1
2 1 0 3
.
L
L
q q q q
q q q q
q q q q
q q q q











ii
ii
ii
ii
On the other hand, we suppose that the spinor
*
corresponds to the real quaternion
q
with the aid of
the transformation
*
f
in the equation (11). In this
case, the right Hamilton spinor matrix of the spinor
*

is
0 3 2 1
*
2 1 0 3
0 3 2 1
2 1 0 3
.
R
R
q q q q
q q q q
q q q q
q q q q











ii
ii
ii
ii
iii) Suppose that the spinor
corresponds to the
real quaternion
qH
with the aid of the
transformation
f
and
ab
Ci
. Then, we get
3 0 0 3
1 2 2 1
aq bq aq bq
aq bq aq bq



i
i
and have the left Hamilton spinor matrix of the
spinor

0 3 3 0 2 1 1 2
2 1 1 2 0 3 3 0
0 3 2 1
2 1 0 3
0.
0
L
aq bq aq bq aq bq aq bq
aq bq aq bq aq bq aq bq
q q q q a b
q q q q a b




ii
ii
i i i
i i i
Consequently, we obtain
L
L


where
0
0



. Similarly, the proof for the right
Hamilton spinor matrix can be obtained.
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iv) We consider that the real quaternion
q
is
1q
.
In this case, the spinor corresponding to
1q
is
1
0



. Consequently, we find that the left
Hamilton spinor matrix related to the spinor
is
2
10
01
LI




. Similarly, we get the right
Hamilton spinor matrix for the real quaternion
1q
as
2
10 .
01
RI




v) Let the spinor corresponding to the real
quaternion
q
be
and the spinor conjugate of the
spinor
be
21
03
ˆqq
qq




i
i
in the equation (6). In
this case, the left Hamilton spinor matrix of the
spinor
ˆ
can be obtained
1 2 3 0
3 0 1 2
0 3 2 1
1
2 1 0 3
ˆ
01 .
10
L
L
q q q q
q q q q
q q q q P
q q q q












ii
ii
ii
ii
ii
Similarly, we obtain that the right Hamilton spinor
matrix of the spinor
*
is
1 2 3 0
*
3 0 1 2
0 3 2 1
1
2 1 0 3
01 .
10
R
R
q q q q
q q q q
q q q q P
q q q q












ii
ii
ii
ii
ii
vi) For the spinors
and
corresponding to the
real quaternions
,pqH
we can write
0 3 2 1 30
2 1 0 3 12
0 3 3 0 2 1 1 2 0 0 1 1 2 2 3 3
2 3 1 0 0 1 3 2 2 0 1 3 0 2 3 1
.
L
q q q q pp
q q q q pp
q p q p q p q p q p q p q p q p
q p q p q p q p q p q p q p q p











ii
i
ii i
i
i
Therefore, we get the left Hamilton spinor matrix
corresponding to the spinor
L

S
as
0 3 2 1 0 3 2 1
2 1 0 3 2 1 0 3
.
L L L
L
q q q q p p p p
q q q q p p p p

i i i i
i i i i
Similarly, we obtain
0 3 3 0 2 1 1 2 0 0 1 1 2 2 3 3
*
2 3 1 0 0 1 3 2 2 0 1 3 0 2 3 1
R
q p q p q p q p q p q p q p q p
q p q p q p q p q p q p q p q p




i
i
and consequently
*.
R R R
R
Proposition 3.9: The left and right Hamilton spinor
matrices
L
and
R
related with the real quaternion
q
are normal.
Proof: Suppose that
is the left Hamilton spinor
matrix related to the real quaternion
.q
Then, we
obtain
0 3 2 1 0 3 2 1
2 1 0 3 2 1 0 3
2222
0 1 2 3
2222
0 1 2 3
2
2
0
0
( ) .
t
LL
q q q q q q q q
q q q q q q q + q
qqqq
qqqq
N q I






i i i i
i i i i
Similarly, if we calculate the equation
t
LL

then,
we have
2
2
()
t
LL N q I

. Consequently, we get
tt
L L L L
and we say that the left Hamilton
spinor matrix
L
is normal. Similar to the left
Hamilton spinor matrix we get
2
2
()
tt
R R R R
N q I

and we see easily that the
right Hamilton spinor matrix
R
is normal.
Consequently, the proof is completed.
Now, we calculate the determinant of the left and
right Hamilton spinor matrices for the real
quaternion
0q
. Hence, we get
2
det( ) det( ) ( )
LR
Nq


.
In this case, we can give the following corollaries.
Corollary 3.10: The left and right Hamilton spinor
matrices
L
and
R
related with the real quaternion
0q
are regular.
Corollary 3.11: The inverses of the left and right
Hamilton spinor matrices where
0qH
are
0 3 2 1
1
2
2 1 0 3
0 3 2 1
1
2
2 1 0 3
1,
()
1.
()
L
R
q q q q
q q q q
Nq
q q q q
q q q q
Nq








+
+
ii
ii
ii
ii
Corollary 3.12: The inverses of the left and right
Hamilton spinor matrices can be written as
1 * 1 *
*
22
11
,
( ) ( )
LR
LR
N q N q


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respectively, where
*
L
and
*
*R
are the left
and right Hamilton spinor matrices related with the
quaternion conjugate
*
q
.
Especially, if we consider that the real quaternion
q
is unit then, we get
1 * 1 *
*
,
LR
LR


Corollary 3.13: The left and right Hamilton spinor
matrices are unitary matrices. It should be
emphasized that
, (2)
LRSU

3.3 The Eigenvalues and Eigenvectors of the
Fundamental Spinor Matrix
In this section, we obtain the eigenvalue and
eigenvector of the fundamental spinor matrix (i.e.
left Hamilton spinor matrix)
L
. Similar equations
can be obtained for the right Hamilton spinor matrix
R
.
We consider that the real quaternion
q
is pure real
quaternion
qq
. Therefore, the fundamental spinor
matrix
p
L
corresponding to the pure quaternion
q
is obtained as
3 2 1
2 1 3
q q q
q q q



L
ii
ii
.
Lemma 3.14: Let the fundamental spinor matrices
be
L
,
L
corresponding to the real quaternion
q
and the pure real quaternion
q
. Hence, the
relationship between these fundamental spinor
matrices is
02 .
LqI

L
Proof: Suppose that the fundamental spinor
matrices
L
and
L
are related with
q
and the pure
quaternion
q
, respectively. Then, we obtain that
0 3 2 1
2 1 0 3
3 2 1
0 0 2
2 1 3
10 .
01
L
q q q q
q q q q
q q q
q q I
q q q










L
ii
ii
ii
ii
Theorem 3.15: The eigenvalues of the fundamental
spinor matrix
L
are
10 ()qN
 qi
and
20 ()qN
 qi
where
0
qqq
and
q
is vectorial
part of the real quaternion
.q
Proof: We suppose that the
L
is the fundamental
spinor matrix. We know that the eigenvalues of the
spinor matrix
L
are obtained with the equation
L

where
C
are the eigenvalues.
Therefore, if we calculate the equation
2
det 0
LI


we get
0 3 2 1
2
2 1 0 3
det 0
L
q q q q
Iq q q q




ii
ii
and we obtain that the characteristic polynomial is
2 2222
0 2 1 0 3
20qqqqq

.
Moreover, if we solve this second-order equation
then we get
1 0 2 0
( ), ( ) .q N q N

qqC.ii
(13)
Corollary 3.16: Let
0 1 2 3
q q q q q i j k
be any
real quaternion
L
be the fundamental spinor matrix
corresponding to the real quaternion
q
and
L
be
the fundamental spinor matrix corresponding to the
pure real quaternion
1 2 3
q q q q i j k
. Therefore,
the eigenvalues of the fundamental spinor matrix
L
are found by adding
0
q
to the eigenvalues of
L
.
Proof: Let
L
and
L
be the fundamental spinor
matrices corresponding to the real quaternion
q
and
the pure real quaternion
q
respectively. Now, we
calculate the roots of the characteristic polynomial
2
det 0
LI

. Therefore, we get
2222
2 3 2 1
det 0
LI q q q

and
12
( ), ( ) .NN

qqCii
(14)
Consequently, if we use equations (13) and (14) we
say that the eigenvalues of the fundamental spinor
matrix
L
are found by adding
0
q
to the
eigenvalues of the fundamental spinor matrix
L
.
Theorem 3.17: Assume that
L
is the fundamental
spinor matrix corresponding to the pure real
quaternion
q
. Moreover, we consider that the
eigenvalue of
L
is
. Therefore, the eigenvalue of
the spinor matrix
2
L
is
2
.
Proof: Suppose that the fundamental spinor matrix
corresponding to the real pure quaternion
q
is
L
.
Now, we find the spinor matrix
2
L
therefore, we
obtain
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222
2
3 2 1
2
222
3 2 1
0.
0
qqq NI
qqq



2
Lq
If we assume that the roots of the characteristics
polynomial
2
2
det( ) 0
LI

are
1
and
2
then,
we have
2
1,2 ( ).N
 q
(15)
Consequently, considering the equations (14) and
(15) we say easily that if the eigenvalue of the
spinor matrix
L
is
then, the eigenvalue of the
spinor matrix
2
L
is
2
.
Corollary 3. 18: The fundamental spinor matrix
L
corresponding to the real quaternion
q
is a non-
defective matrix.
Proof: We see that the number of eigenvalues of the
fundamental spinor matrix
L
is equal to its number
of dimensions. In this case, the fundamental spinor
matrix is a non-defective matrix.
Theorem 3.19: The eigenspaces corresponding to
the
10
qN
 qi
and
20
qN
 qi
eigenvalues of the fundamental spinor
L
are,
respectively,
L
S
and
L
S
where the spinors are
3
12
()qN
qq



q
i
,
3
12
()qN
qq



q
i
and
,
LL

are the fundamental
spinor matrices of the spinors
,.

Proof: Let the fundamental spinor matrix of the
spinor
S
corresponding to the real quaternion
qH
be
L
. Firstly, we obtain the eigenspace for
the eigenvalue
10 .qN
 qi
Then, we consider
the spinor
3
12
() .
qN
qq



qii
i
In this case, the
fundamental spinor matrix of the spinor
is
3 2 1
2 1 3
() .
()
L
N q q q
q q N q



q
q
ii
ii
Moreover, let
S
be any spinor such that
30
12





i
i
. In this case, the spinor
L

S
is
calculated as
3 0 2 1 1 2 0 1 1 2 2 3 3 3
2 3 1 0 3 2 2 2 0 1 3 3 1 1
( ) ( )
( ) ( )
L
q q q N q q q N
q q q N q q q N




qq
qq
i
i
On the other hand, for the fundamental spinor
matrix
L
we know that
3 2 1
12
2 1 3
() .
()
L
N q q q
Iq q N q




q
q
ii
ii
If we calculate the equation
12LL
I
then,
we obtain
12
00.
0
LL
I



Consequently,
the eigenspace for the eigenvalue
10
qN
 qi
consists of the spinors
.
L

Similarly, the eigenspace for the eigenvalue
20
qN
 qi
of the fundamental spinor matrix
L
can be obtained. For this, we consider the spinor
3
12
() .
qN
qq




qii
i
Therefore, the fundamental
spinor matrix of the spinor
is
3 2 1
2 1 3
() .
()
L
N q q q
q q N q


q
q
ii
ii
Consequently, if we make the necessary
arrangements we obtain
12 0
LL
I

and see
that the eigenspace for the eigenvalue
20
qN
 qi
consists of the spinors
.
L

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