1. Introduction
A generalization of the second-order sequences is the
Fibonacci sequence. Suvarnamani and Tatong [
2] defined
Fibonacci sequence,
, that has initial terms
and
, and for
, holds the following recurrence relation:
where
and
are nonzero real numbers such that
.
The first few
Fibonacci numbers are
The characteristic equation of (1) is
Binet’s formula of the
is as follow
where
and
are roots of (2) [
2].
Furthermore, there are many more articles on
Fibonacci sequence [
2,
3,
4,
5,
6,
7,
8].
Quaternions have become a popular subject of study by researchers, especially in recent years. In 1843, Hamilton [
9] introduced quaternions that extended complex numbers. In addition, a set of quaternions is defined by Hamilton as follows:
where
is the set of real numbers,
The quaternions can be thought of as four-dimensional vectors, just as complex numbers can be thought of as two-dimensional vectors [
9] because the quaternions are extensions of complex numbers into a four-dimensional space.
In addition, new quaternions can be defined by combining quaternions and different number sequences. For example,
nth Fibonacci quaternions [
4] are defined as follows:
where
is the
Fibonacci number. Also, the imaginary quaternion units
and
have the rules in (4). There are many more works on quaternions in literature (see, for example, [
2,
6,
7,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20]).
Another popular number sequence is the bicomplex numbers. In 1892, it is defined bicomplex numbers [
21] by four base elements
where
In that case, any bicomplex number
can be written as follows:
where
and
is the set of real numbers. Let
and
are two bicomplex numbers. Then, it is written the addition, subtraction, and multiplication of the bicomplex numbers in the following form:
respectively.
Moreover, there are three different conjugations of the bicomplex numbers as follows:
For more information on bicomplex numbers, refer to the resources in [
7,
8,
14,
18,
19,
22,
23,
24,
25,
26,
27].
There are also studies in which bicomplex numbers and number sequences and bicomplex numbers and quaternion sequences are used together [
8,
14,
15,
18,
19,
20,
23,
25,
26,
27].
Here, we obtain a generalization of second-order bicomplex number and bicomplex quaternion sequences. We give some of their equations, including the Binet formula, generating function, Catalan, Cassini, d’Ocagne’s identities, and summation formulas for bicomplex Fibonacci numbers and bicomplex Fibonacci quaternions. In addition, we describe a matrix that we call N-matrix of type 4 × 4 for bicomplex Fibonacci quaternions whose terms are bicomplex Fibonacci numbers. Then, we obtained that the bicomplex Fibonacci quaternions can be expressed as the 8 × 8 real matrices. Finally, we create a special matrix for bicomplex Fibonacci quaternions, we obtain some equations about the matrix, and we obtain the determinant of a special matrix that gives the terms of that quaternion.
2. Bicomplex Fibonacci Numbers
Here, we describe the bicomplex Fibonacci numbers. Some equations and summation formulas about bicomplex Fibonacci number sequence are given. In addition, the generating function, Binet’s formula, Catalan, Cassini, and d’Ocagne’s identities are obtained for these number sequences.
Definition 1.
The bicomplex Fibonacci numbers are introduced by
where is the Fibonacci number and are bicomplex units that provide (5).
In the remainder of the study, will be considered as Fibonacci number.
The first few terms of bicomplex
Fibonacci sequence are the following:
For
, it is given the following identity with simple calculation
Thus, the characteristic equation of (8) is
Let any two bicomplex
Fibonacci numbers be
and
. The addition, subtraction, and multiplication for them are written as follows:
The multiplication of a bicomplex
Fibonacci number by the real scalar
is described as the following:
Furthermore, bicomplex
Fibonacci numbers have three different conjugations, which can be written as follows:
Theorem 1.
Let and be two bicomplex Fibonacci numbers. In that case, it can be given the following for bicomplex Fibonacci numbers about the different three conjugates of these numbers:
Proof. By using (10)-(12), these identities can be obtained with simple mathematical calculations. □
Theorem 2.
Binet’s formula of the bicomplexFibonacci numbers is given in the following equation for ( is any integer),
where and are roots of (9).
Proof. By using (8) and (4), we have following equation:
Thus, Binet’s formula of the bicomplex Fibonacci numbers is easily given with some simple computation. □
In the remainder of the study, will be considered as bicomplex Fibonacci number.
Theorem 3.
The generating function of the bicomplex Fibonacci numbers is
Proof. To find the generating function of
, we will first use the following equation.
Using (9) and initial conditions, we have
Theorem 4.
The exponential generating function of the bicomplexFibonacci numbers is
Proof. To find the exponential generating function of
, firstly, we will use the following equation:
By using (14) and
, the exponential generating function of
is obtained
Theorem 5.
For , Catalan identity for bicomplex Fibonacci numbers is as follows:
where and are positive integers.
Proof.
Because and are roots of (10), and and, we obtain
Thus, we obtain . □
If in the Catalan identity, Cassini identity is obtained as follows:
Corollary 1.
For , Cassini identity for bicomplex Fibonacci numbers is as follows:
where is an integer.
Theorem 6.
D’Ocagne’s identity for bicomplexFibonacci numbers is as follows:
Now, we give some identities about summations of terms in the bicomplex Fibonacci numbers.
Theorem 7.
For are natural number, the summation formula of bicomplex Fibonacci numbers is
Proof. Firstly, we assume that
In this situation,
In addition, we know that from the equ (13) in [
5]
With simple calculations, we obtain
Now, let ,
We obtain that from the equ (13) in [
5],
. Moreover, we have
. Thus,
□
Proof. According to the lemma in [
17] for
Fibonacci numbers, we know that
Using (7) and (15),
□
3. Bicomplex Fibonacci Quaternions
Here, we describe the bicomplex Fibonacci quaternions. Some equations and summation formulas about bicomplex Fibonacci quaternion sequence are given. In addition, the generating function, Binet’s formula, Catalan, Cassini, and d’Ocagne’s identities are obtained for these quaternions.
Definition 2.
The bicomplex Fibonacci quaternions are defined by
where + is the Fibonacci quaternion, , .
Thus, bicomplex
Fibonacci quaternion with four bicomplex components can be written as
By using (8), we obtain the following equation
Thus, the first few terms of the bicomplex
Fibonacci quaternions are
Therefore, any bicomplex
Fibonacci quaternion occurs of a scalar part and vectorial part expressed as follows;
Here, the set of bicomplex Fibonacci quaternions will be denoted by . And in the remainder of the study, and will be considered as bicomplex Fibonacci andFibonacci quaternion, respectively.
Let
be two bicomplex
Fibonacci quaternions. The addition and the subtraction of them are
The multiplication of a bicomplex
Fibonacci quaternion by the real scalar
is described as follows:
The product of any two bicomplex
Fibonacci quaternions
and
where
and
represent the dot product and the cross product of
and
, respectively. The conjugate operation in
is
whereas the bicomplex conjugates are
The features of quaternion algebra are adapted to bicomplex quaternions as well as to complex quaternions. In this situation, some key properties in bicomplex quaternions change. Because the norm of a real quaternion is defined by , the norm is positive definite and real. But, we consider the complex quaternion; the norm is described according to the inner product of a complex quaternion with itself. That is, for a complex quaternion , the norm of can be written as .
Since the components of
are complex numbers, the norm of
has a complex value. In [
15], the norm of a complex Fibonacci quaternion can be given as follows;
In addition, we described the norm of any bicomplex quaternion, in terms of the inner product of a bicomplex quaternion with itself as in the definition of a complex quaternion. Then for any bicomplex quaternion
, the norm of
can be written as
. In this situation, the norm of a bicomplex
Fibonacci quaternion can be given as follows;
Also, we obtained that there are four different conjugates of bicomplex Fibonacci quaternion, whereas there are three different conjugates of bicomplex Fibonacci numbers. Furthermore, the following inequalities get about four different conjugations of bicomplex Fibonacci quaternion.
Theorem 9.
Let and be two bicomplex Fibonacci quaternion. In that case, we obtain the following inequalities about the four conjugates of them:
Proof. Using conjugate operations in and (16), the above identities can be easily proved.□
The following equation for the elements of
is easily obtained using (16)
Thus, the characteristic equation of (18) is
Theorem 10.
Binet’s formula of the bicomplex Fibonacci quaternions is given by the following equation for,
where and are roots of (19) and
Proof. By using (16) and (13), we have the following equation:
Thus, Binet’s formula of the bicomplex Fibonacci quaternion is easily found with some simple computation. □
Theorem 11.
The generating function of the bicomplex Fibonacci quaternions is determined by
Proof. To obtain the generating function of
, we use power series representation of
.
Using (18) and initial conditions, we have
□
Theorem 12.
The exponential generating function of the bicomplexFibonacci quaternions is
Proof. To obtain the exponential generating function of
, we use the power series representation of
.
Using (20) and
, we have
Theorem 13.
For , Catalan identity for bicomplex Fibonacci quaternions is as follows:
where and are positive integers.
Proof.
Because
and
are roots of (19),
If in the Catalan identity, Cassini identity is obtained as follows:
Corollary 2.
For , Cassini identity for bicomplex Fibonacci quaternions is as follows:
where is an integer.
Theorem 14.
D’ocagne’s identity of bicomplex Fibonacci quaternions for is as follows:
Now, we give some identities about summations of terms in the bicomplex Fibonacci quaternions.
Theorem 15.
For are natural number, the summation formula of bicomplex Fibonacci quaternions is
Proof. Firstly, we assume that
In this situation,
. In addition, we obtain that by using the equ (13) in [
5],
. With simple calculations, we get
Now, we assume that
. We obtain that by using the equ (13) in [
5],
. Moreover, we have
Proof. Using (7) and (17),
4. Matrix Representation of Bicomplex Fibonacci Quaternions and an Application in This Representation for Them
Firstly, we will use the matrix that generates
, which we define to obtain the
N-matrix, which is similar to the definition of the
S-Matrix defined in [
11]. We know that
By using (21), The
N-matrix is defined as
where
,
.
Here, we will define the
-matrix that we called the bicomplex
Fibonacci quaternion matrix as follows:
Now, we can give the following theorem about the -matrix.
Theorem 17.
If be the bicomplex Fibonacci quaternion. Then, for
Proof. To do this, we apply induction on . If , it is clear that (23) holds. Now, we suppose that (23) is hold for , that is, .
Using the Eq. (18), for
,
. Then, by induction,
Thus the Eq. (23) holds for all .
Proof. The proof can be easily seen by the coefficient (2, 1) of the matrix and the Eq. (22).
Theorem 18.
For , ( is an integer) and . Then
Proof. We prove the theorem by induction on
. If
then the result is clear. Now we assume that, for any integer
such as
,
Then for
, we obtain
where
. Therefore, the proof is completed.
In [
15], it is obtained the complex Fibonacci quaternions are shown by the 8 × 8 real matrices. First, we obtained the matrix form of a bicomplex
Fibonacci quaternion
with the aid of 4 × 4 matrix representations and produced a new 8 × 8 type bicomplex quaternion matrix similarly. We can define the following matrices.
where
Using the matrices
and
, we obtain
and
, where
is the 4 × 4 identity matrix. Furthermore, it satisfies the following equations:
The bicomplex
Fibonacci quaternion
is also expressed by the 4×4 matrix with these new matrices. By the bicomplex
Fibonacci number, we can write
Theorem 19.
For , the term of the bicomplex Fibonacci quaternion sequence with the determinant of a special matrix can be obtained as follows:
Proof. For the proof, we use the induction method on
. It is clear that equality holds for
. Now, suppose that the equality is true for
. Then, we can verify it for
as follows:
Thus, the proof is completed.
5. Conclusions
Here, we investigated Fibonacci numbers, quaternions, bicomplex numbers, and bicomplex quaternions. And we introduced bicomplex Fibonacci numbers and bicomplex Fibonacci quaternions based on these numbers. That is, we obtain a generalization of second-order bicomplex number and bicomplex quaternion sequences. Furthermore, some of their equations include the Binet formula, generating function, Catalan, Cassini, and d’Ocagne’s identities, and some summation formulas for both of them.
In addition, we describe a matrix that we call N-matrix of type 4 × 4 for bicomplex Fibonacci quaternions whose terms are bicomplex Fibonacci numbers. Then, we obtained that the bicomplex Fibonacci quaternions can be expressed as the 8 × 8 real matrices. With the help of the new four matrices we defined in 4 × 4 type, we obtained { which is used as the basic elements of real quaternions . Also, we obtained that the bicomplex Fibonacci quaternion can also be expressed with a new matrix of type 4 × 4, whose elements consist of bicomplex Fibonacci numbers.
Finally, we create a matrix for bicomplex Fibonacci quaternions, and we obtain a determinant of a special matrix that gives the terms of that quaternion.
Author Contributions
All authors contributed equally to this work. All authors read and approved the final manuscript.
Funding
This research received no external funding.
Acknowledgments
The authors would like to express their sincere gratitude to the referees for their valuable comments, which have significantly improved the presentation of this paper.
Conflicts of Interest
The authors declare no conflict of interest.
References
- Koshy, T. Fibonacci and Lucas Numbers with Applications; A Wiley Inter science publication, U.S.A, 2001.
- Suvarnamani, A.; Tatong, M. Some properties of (p,q)-Fibonacci numbers. Progress in Applied Science and Technology 2015, 5, 17–21. [Google Scholar]
- Diskaya, O.; Menken, H. On the (p,q)-Fibonacci N-dimensional recurrences. Bulletin of the International Mathematical Virtual Institute. 2022, 12, 205–212. [Google Scholar]
- İpek, A. On (p, q)-Fibonacci quaternions and their Binet formulas, generating functions and certain binomial sums. Advances in Applied Clifford Algebras. 2017, 27, 1343–1351. [Google Scholar] [CrossRef]
- Liu, L. On the spectrum and spectral norms of r-circulant matrices with generalized-Horadam numbers entries. International Journal of Computational Mathematics. 2014, 2014, 795175. [Google Scholar] [CrossRef]
- Patel, B. K.; Ray, P. K. On the properties of (p, q)-Fibonacci and (p, q)-Lucas quaternions. Mathematical Reports. 2019, 21, 15–25. [Google Scholar]
- Yağmur, T. A note on hyperbolic (p, q)-Fibonacci quaternions. Communications Faculty of Sciences University of Ankara Series A1 Mathematics and Statistics. 2020, 69, 880–890. [Google Scholar] [CrossRef]
- Yazlık, Y.; Köme, S.; Köme, C. Bicomplex generalized k-Horadam quaternions. Miskolc Mathematical Notes. 2019, 20, 1315–1330. [Google Scholar] [CrossRef]
- Hamilton, W. R. Elements of quaternions; Green, & Company, London: Longmans 1866.
- Horadam, A.F. Complex Fibonacci Numbers and Fibonacci Quaternions. American Math. Monthly. 1963, 70, 289–291. [Google Scholar] [CrossRef]
- Cerda-Morales, G. On a generalization for Tribonacci quaternions. Mediterranean Journal of Mathematics. 2017, 14, 1–12. [Google Scholar] [CrossRef]
- Akyiğit, M.; Kösal, H. H.; Tosun, M. Split Fibonacci quaternions. Advances in applied Clifford algebras. 2013, 23, 535–545. [Google Scholar] [CrossRef]
- Flaut, C.; Shpakivskyi, V. On generalized Fibonacci quaternions and Fibonacci-Narayana quaternions. Advances in Applied Clifford Algebras. 2013, 23, 673–688. [Google Scholar] [CrossRef]
- Gül, K. Dual bicomplex Horadam quaternions. Notes on Numbers Theory and Discrete Mathematics. 2022, 26, 187–205. [Google Scholar] [CrossRef]
- Halici, S. On complex Fibonacci quaternions. Advances in Applied Clifford Algebras. 2013, 23, 105–112. [Google Scholar] [CrossRef]
- Halici, S.; Karataş, A. On a generalization for Fibonacci quaternions. Chaos, Solitons & Fractals. 2017, 98, 178–182. [Google Scholar]
- Iar, Z. S.; Keskin, R. Some new identities concerning generalized Fibonacci and Lucas numbers. Hacet. J. Math. Stat. 2013, 42, 211–222. [Google Scholar]
- Kızılateş, C.; Catarino, P.; Tuğlu, N. On the bicomplex generalized Tribonacci quaternions. Mathematics. 2019, 7, 80. [Google Scholar] [CrossRef]
- Tan, E.; Yilmaz, S.; Sahin, M. On a new generalization of Fibonacci quaternions. Chaos, Solitons and Fractals. 2016, 82, 1–4. [Google Scholar] [CrossRef]
- Yağmur, T. On generalized bicomplex k-Fibonacci numbers. Notes Number Theory Discrete Math. 2019, 25, 132–133. [Google Scholar] [CrossRef]
- Segre, C. Le rappresentazioni reali delle forme complesse e gli enti iperalgebrici. Mathematische Annalen. 1892, 40, 413–467. [Google Scholar] [CrossRef]
- Elizarrarás-Luna, M.E.; Shapiro, M.; Struppa, M.; Vajiac, A.D.C. The bicomplex numbers. In Bicomplex Holomorphic Functions; Frontiers in Mathematics, Birkhuser: Cham, Switzerland, 2015; pp. 5–28. [Google Scholar]
- Halıcı, S. On Bicomplex Fibonacci Numbers and Their Generalization, Models and Theories in Social Systems, 179, 509-524, Springer, 2019.
- Luna-Elizarraras, M.E.; Shapiro, M.; Struppa, D.C.; Vajiac, A. Bicomplex numbers and their elementary functions. Cubo. 2012, 14, 61–80. [Google Scholar] [CrossRef]
- Nurkan, S.K.; Güven, I. A, A note on bicomplex Fibonacci and Lucas numbers. Internat. J. Pure Appl. Math. 2018, 120, 365–377. [Google Scholar]
- Rochon, D.; Shapiro, M. On algebraic properties of bicomplex and hyperbolic numbers. An. Univ. Oradea Fasc. Mat. 2004, 11, 71–110. [Google Scholar]
- Torunbalcı Aydın, F. Bicomplex Fibonacci quaternions. Chaos Solutions and Fractals. 2018, 106, 147–153. [Google Scholar] [CrossRef]
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