EUROPEAN JOURNAL OF PURE AND APPLIED MATHEMATICS Vol. 10, No. 5, 2017, 995-1004 ISSN 1307-5543 – www.ejpam.com Published by New York Business Global Fractional orders of the generalized Bessel matrix polynomials M. Abdalla1,∗, M. M. Haidan2 1 Department of Mathematics, Faculty of Science, South Valley University, Qena 83523, Egypt 2 Department of Mathematics, Faculty of Science for Girls, King Khalid University, Abha, Saudi Arabia Abstract. This paper presents and investigates generalized Bessel matrix polynomials (GBMPs) with order α ∈ < (the set of real numbers). The given result is supposed to be an enhanced and a generalized form of the scalar form to the fractional analysis setting. By using the Liouville- Caputo operator of fractional analysis and Rodrigues type representation form of fractional order, the generalized Bessel matrix functions (GBMFs) Yα(t;A,B), t ∈ C, for matrices A and B in the complex space CN×N are derived and supplied with a matrix hypergeometric representation that are satisfied by these functions. Subsequently, a fractional matrix recurrence relationship, a fractional matrix of second-order differential equation and an orthogonal system are then developed for GBMFs. 2010 Mathematics Subject Classifications: 33C05, 33C45, 34A05. Key Words and Phrases: Fractional calculus, Generalized Bessel matrix polynomials, Ro- drigues’ formula 1. Introduction The generalized Bessel polynomials (GBPs) formula, a class of orthogonal polyno- mials which is intimately related with the Bessel functions. They emerged in the solution of differential equation of spherical waves. These polynomials have been studied first by Bochner [4] who pointed out their connection with Bessel functions. A comprehensive study on these polynomials was given by Krall and Frink [17]. Several other authors (see, e.g., [2, 5, 12]) have contributed to the study of the Bessel polynomials. Special matrix functions latterly show in several fields (see, for example [15, 24, 25]). A new extension of hypergeomatric, Humbert and Appel matrix functions were introduced and studied in [19, 20, 21]. In [1, 22] the scalar case of the generalized Bessel and reverse Bessel polynomials have already been expanded into matrix setting. ∗Corresponding author. Email addresses: mabdomath85@gmail.com, m.abdallah@sci.svu.edu.eg. (M. Abdalla), mhedan@kku.edu.sa (M. Haidan) http://www.ejpam.com 995 c© 2017 EJPAM All rights reserved. M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 996 Several articles and books have been written recently in fractional calculus area, of which we recommend (for instance, [6, 7, 10, 11, 29, 14, 18, 26, 27, 32]). In recent years, many researchers have studied various special functions associated with fractional calculus. Laguerre polynomials, Bell polynomials, Legendre polynomials and generalized ultraspherical or Gegenbauer functions of arbitrary (fractional) orders have been defined in [8, 9, 30, 31]. In addition, fractional derivatives of various multivariable functions have been derived (for examples, [3, 23]). The major purpose of this work is to obtain generalizations of the (GBMPs) by making use of fractional calculus and Rodrigues type exemplification form of fractional order. Therefore, the (GBMPs) with fractional order are obtained and some of their properties such as a fractional matrix recurrence relations, the fractional matrix differential equation and an orthogonality property are given. Starting, we mention some the fundamental definitions of the fractional calculus and some properties of the matrix functions used in the present work. Definition 1. The fractional integral of order β ∈ <+, being the set of positive real numbers, of the function f(τ), τ ≥ b is defined by (see [13, 28] and [26] ) Iβb f(τ) = ∫ τ b (τ − u)β−1 Γ(β) f(u) du. (1) The Liouville-Caputo fractional derivative of order α ∈ (n − 1, n) (n ∈ N := {1, 2, ...}) of f(τ), τ ≥ a is defined by Dα b f(τ) = In−αb Dn f(τ), D = d dτ . (2) The fractional derivative of the product g(v)f(v) by [26], the Leibniz rule for fractional differentiation takes the form Dα[g(v)f(v)] = ∞∑ s=0 ( α s ) g(s)(v)Dα−sf(v). (3) Definition 2. (cf. [1, 16]) For all A in the complex space of matrices CN×N , and A + nI is invertible for all n ∈ N0 := N ∪ {0}, (4) then the Pochhammer symbol (the shifted factorial) is defined by (A)n = A(A + I)...(A + (n− 1)I) = Γ(A + nI)Γ−1(A); (A)0 ≡ I. (5) where I is unite matrix in CN×N . Definition 3. [1, 16] Suppose that A,B and D are matrices in CN×N , and D satisfy con- dition (4), then, the matrix power series of the hypergeometric matrix function is defined in the form F (A,B;D; z) = ∞∑ m=0 (A)m(B)m[(D)m]−1 m! zm. (6) M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 997 2. Generalized Bessel matrix functions of fractional order The classical (GBMPs) Yn(z,A,B) are defined by Rodrigues’ type formula (see [1, 22]) Yn(z,A,B) = B−nz2I−Ae B z Dn ( z2(n−1)I+Ae −B z ) , (7) where n ≥ 0, A and B are parameter matrices. When A = B = 2I, the analogue Rodrigues’ type formula for the (GBMPs) (7) reduces to the analogue Rodrigues’ type formula Bessel polynomials proper: yn(z) = 2−ne 2 z Dn ( z2ne −2 z ) . (8) By taking the the Liouville-Caputo fractional derivative Dα in (7), we introduce functions which are naturally refereed to as generalized Bessel matrix functions (GBMFs). Definition 4. Suppose that α ∈ (n− 1, n) (n ∈ N) and A and B are commuting matrices in CN×N satisfying the spectral condition (4). Then the GBMFs are defined by the formula Yα(t;A,B) = B−αt2I−Ae B t Lα(t); Lα(t) = Dα(tA+(2α−2)Ie− B t ). (9) Using (9), the GBMFs would be represented by the hypergeometric matrix function 1F1(A,B; t) in the following result: Theorem 1. The GBMFs can be written as Yα(t;A,B) =(tB−1)αΓ−1(A + (α− 1)I)Γ(A + (2α− 1)I) ×1F1(−αI;−A + 2(1− α)I; B t ). (10) Proof. From (9) and the relation (3), we find that Yα(t;A,B) =B−αt2I−Ae B t Dα ∞∑ s=0 (−B)s s! tA+(2α−2−s)I =B−αt2I−Ae B t ∞∑ s=0 (−B)s s! tA+(α−2−s)I × Γ−1(A + (α− 1− s)I)Γ(A + (2α− 1− s)I) =(tB−1)αe B t ∞∑ s=0 (−B)s s! t−s × Γ(A + (2α− 1− s)I) Γ−1(A + (α− 1− s)I) =(tB−1)α Γ(A + (2α− 1)I) Γ−1(A + (α− 1)I) × 1F1(−αI;−A + 2(1− α)I; B t ), which yields the desired result. M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 998 3. Recurrence relations and the differential equation In this section, we shall show some recurrence relations for the matrix functions Yα(t;A,B) which generalize (interpolate) those of the GBMPs Yn(z,A,B) (see[1, 22]). In addition, we generalize the GBMFs (9) by solving the following linear homogeneous fractional matrix differential equation: t2 Y ′′α(t;A,B) + (tA + B) Y ′α(t;A,B) = α(A + (α− 1)I) Yα(t;A,B). The following lemma enables us to establish Theorem 2. Lemma 1. Suppose that A and B are commuting matrices in CN×N satisfying the condi- tion (4). For any α ∈ (n− 1, n) (n ∈ N), (i) Lα+1(t) (A + (α − 1)I)(A + 2(α − 1)I) = Lα(t) [ (A + 2αI)(A + 2(α − 1)I)t + B(A − 2I) ] (A + (2α− 1)I) + Lα−1(t) α B2(A + 2αI). (ii) Lα+1(t) (A + (α− 1)I) = L′α(t) (A + 2αI)t2 + Lα(t) [ (A + 2αI)(α+ 1)t− B(α+ 1) ] . (iii) Lα+1(t) (A+2(α−1)I)t2 = [ (A+2(α−1)I)(A+(α−2)I)t+B(A+(α−2)I) ] Lα(t)+ Lα−1(t)B2α. Proof. (i) Using the Leibniz rule for fractional derivative [26], the fractional derivative in (9) yields (A + (α− 1)I)(A + 2(α− 1)I) Lα+1(t) =(A + (α− 1)I)(A + 2(α− 1)I)(A + 2αI) DαtA+(2α−1)I e −B t + B(A + (α− 1)I)(A + 2(α− 1)I) Lα(t) =(A + (α− 1)I)(A + 2(α− 1)I)(A + 2αI)t Lα(t) +α(A + (α− 1)I)(A + 2(α− 1)I)(A + 2αI)Dα−1tA+2(α−1)I e −B t +B(A + (2α− 1)I)(A− 2I) Lα(t) +α B(A + 2αI) [ (A + 2(α− 1)I) Dα−1tA+(2α−3)I e −B t + B Lα−1(t) ] = [ (A + (α− 1)I)(A + 2(α− 1)I)(A + 2αI)t+ B(A + (2α− 1)I)(A− 2I) +α(A + 2(α− 1)I)(A + 2αI)t ] Lα(t) + α B2 (A+ 2αI) Lα−1(t). Hence, (A + (α− 1)I)(A + 2(α− 1)I)Lα+1(t) = [ (A + 2αI)(A + 2(α− 1)I)t+ B(A− 2I) ] (A + (2α− 1)I) Lα(t) + αB2(A + 2αI) Lα−1(t). (11) M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 999 (ii) We have Lα+1(t) = t2 Dα+1tA+2(α−1)I e −B t + 2(α+ 1)t DαtA+2(α−1)I e −B t +α(α+ 1) Dα−1tA+2(α−1)I e −B t = t2 L′α(t) + 2(α+ 1)t Lα(t) +α(α+ 1) Dα−1tA+2(α−1)I e −B t (12) and Lα+1(t) =(A + 2αI) DαtA+(2α−1)I e −B t + B Lα(t) = [ (A + 2αI)t+ B ] Lα(t) +α(A + 2αI) Dα−1tA+2(α−1)I e −B t . (13) If we multiply (12) by (A+ 2αI) and (13) by (α+ 1), then subtract we obtain the required result. (iii) Multiply both sides of the equation (ii) above by (A + 2(α− 1)) and substitute for (A + (α − 1)I)(A + 2(α − 1)I)Lα+1(t) from (i) in (ii) and on rearrangement, we obtain (iii). To prove the following result: Theorem 2. Suppose that A and B are commuting matrices in CN×N satisfying the condition (4). Then the GBMFs satisfy the following recurrence relations: (A + (α− 1)I)(A + 2(α− 1)I) Yα+1(t;A,B) = [ (A + 2αI)(A + 2(α− 1)I)tB−1 + (A− 2I) ] (A + (2α− 1)I) Yα(t;A,B) + α(A + 2αI) Yα−1(t;A,B). (14) (A + 2αI)t2 Y ′α(t;A,B) = B(A + (α− 1)I) Yα+1(t;A,B) − (A + (α− 1)I)[(A + 2αI)t+ B] Yα(t;A,B). (15) (A + 2(α− 1)I)t2 Y ′α(t;A,B) = α B Yα−1(t;A,B) + [α (A + 2(α− 1)I)t− α B] Yα(t;A,B). (16) Y ′α(t;A,B) [(A + 2(α− 1)I)t+ B] (A + (α− 2)I) +α B Yα−1(t;A,B) = α (A + (α− 2)I)(A + 2(α− 1)I) Yα(t;A,B). (17) M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 1000 Proof. Using Lemma 1, substitute for Lα+1(t) = Bα+1tA−2Ie −B t Yα+1(t;A,B), Lα(t) = BαtA−2Ie −B t Yα(t;A,B) and Lα−1(t) = Bα−1tA−2Ie −B t Yα−1(t;A,B), in (i), (ii) and (iii) respectively, we get (14), (15) and (16). If we multiply (16) by 1 t2 [ (A + (α− 1)I)[(A + 2(α− 1)I)t+ B](A + 2(α− 1)I)−1 ] and multiply (15 ) by 1 t2 [ αB(A + 2(α− 1)I)−1 ] after replace α by α− 1 and add, we obtain Eq.(17). Other recurrence relations for the GBMFs Yα(t;A,B) may be derived from the rela- tions in Theorem 2. Now, the major property developed here is the differential equation for the GBMFs Yα(t;A,B) which is derived from their recurrence relation established by Theorem 2. By differentiating equation (16) we find t2 (A + 2(α− 1)I) Y ′′α(t;A,B) +2t (A + 2(α− 1)I) Y ′α(t;A,B) =α[t(A + 2(α− 1)I)− B] Y ′α(t;A,B) +α(A + 2(α− 1)I) Yα(t;A,B) + α B Y ′α−1(t;A,B). (18) From (17) and (18), a straightforward computation shows that t2 (A + 2(α− 1)I) Y ′′α(t;A,B) + 2t (A + 2(α− 1)I) Y ′α(t;A,B) =α(A + (α− 1)I)(A + 2(α− 1)I)Yα(t;A,B), t2 (A + 2(α− 1)I) Y ′′α(t;A,B) + [t(A + 2(α− 1)I)A +B(A + 2(α− 1)I)] Y ′α(t;A,B) =α(A + (α− 1)I)(A + 2(α− 1)I)Yα(t;A,B). Thus, t2 Y ′′α(t;A,B) + (tA + B) Y ′α(t;A,B) = α(A + (α− 1)I) Yα(t;A,B). (19) Therefore the following theorem is proved. Theorem 3. Let A and B be commuting matrices in CN×N , satisfying the spectral condi- tion (4). Then the GBMFs satisfies fractional matrix differential equation in (19). M. Abdalla, M. M. Haidan / Eur. J. Pure Appl. Math, 10 (5) (2017), 995-1004 1001 4. Orthogonality property The research subject of an orthogonal system for the GBMFs is discussed in this section with the weight function %(t) which is defined by (see, [22]) %(t) = 1 2πi ∞∑ s=0 Γ−1(A + (s− 1)I) Γ(A) ( −B t )s, (20) which satisfies the related matrix nonhomogeneous equation %(t) ′ (t2 = %(t)(At+ B)− [(A− 2I)(A− I)]t 2πi . (21) When the relation (19) is multiplied by %(t), we get Y ′α(t;A,B)) ′ (t2%(t)− Y ′α(t;A,B) (t2%(t)) ′ + Y ′α(t;A,B) (At+B)%(t) =Yα(t;A,B) αI(A + (α− 1)I)%(t), and using (21), we have (zt2%(t)Y ′α(t;A,B)) ′ + [(A− I)(A− B)]t 2πi Y ′α(t;A,B) =αI(A + (α− 1)I)Yα(t;A,B)%(t). (22) Multiplying Yγ(t;A,B) in (22) and and integrating the result around the unit circle, one gets ∫ C (t2%(t)Y ′α(t;A,B)) ′Yγ(t;A,B) dt + ∫ C [(A− I)(A− 2I)]t 2πi Y ′α(t;A,B) Yγ(t;A,B) dt = αI(A + (α− 1)I) ∫ C %(t)Yα(t;A,B)Yγ(t;A,B) dt. (23) Consider the straightforward computation integrating, we see that αI(A + (α− 1)I) ∫ C %(t)Yα(t;A,B)Yγ(t;A,B) dt =− ∫ C t2%(t)Y ′α(t;A,B)Y ′γ(t;A,B) dt. (24) Interchanging α and γ, that is γI(A + (γ − 1)I) ∫ C %(t)Yα(t;A,B)Yγ(t;A,B) dt =− ∫ C t2%(t)Y ′α(t;A,B)Y ′γ(t;A,B) dt REFERENCES 1002 and subtracting gives [αI(A + I(α− 1))− γI(A + (γ − 1)I)] ∫ C %(t)Yα(t;A,B)Yγ(t;A,B) dt = 0. Finally, for α 6= γ, we get∫ C %(t)Yα(t;A,B)Yγ(t;A,B) dt = 0. (25) This result can be expressed as follows: Theorem 4. For any real numbers α 6= γ and let A and B be commutative matrices in CN×N , satisfying the condition (4), then expression (25) hold true. Acknowledgment The authors are very grateful to the anonymous referees for many valuable comments and suggestions which helped to improve the paper. References [1] M. Abul-Dahab, M. Abul-Ez, Z. Kishka and D. Constales, Reverse generalized Bessel matrix differential equation, polynomial solutions,and their properties, Math. Meth. Appl. Sci., (2015), 1005-1013. [2] M. Abul-Ez, Bessel polynomial expansions in spaces of holomorphic functions, J. Math. Anal. Appl., 221, (1998), 177-190. [3] R. Aktaş, R. şahin and F. Tşdelen, Multivariable Jacobi polynomials via fractional calculus, Journal of Fractional Calculus and Applications., 4, (2013), 335-348. [4] S. Bochner, Uber Sturn-Liouvillische Polynomsysteme, Math. Zeits., 29, (1929), 730-736. [5] J. Burchnall, The Bessel polynomials, Canad. J. Math., 3, (1951), 62-67. [6] K. Diethelm, The Analysis of Fractional Differential Equations., Springer, Berlin, 2010. [7] A. El-Sayed , Linear differential equations of fractional order, Appl. Math. and Com- put., 55, (1993), 1-12. [8] A. El-Sayed, Laguerre polynomials of arbitrary ( fractional) orders, Appl. Math. Com- put., 109, (2000), 1-9. [9] A. El-Sayed and S. Rida, Bell polynomials of arbitrary (fractional) orders, Appl. Math. Comput., 106 (1999) 51-62. REFERENCES 1003 [10] A. Erdelyi, Axially symmetric potentials and fractional integration, SIAM J. Appl. Math., 13, (1965), 216-228. [11] A. Erdelyi, An integral equation involving Legendre polynomials, SIAM J. Appl. Math., 12, (1964), 15-30. [12] E. Grosswald, Bessel Polynomials, Lecture Notes in Mathematics., vol. 698, Springer, Berlin, 1978. [13] R. Gorenflo and F.Mainardi, Fractional Calculus: Integral and Differential Equations of Fractional Order, in A. Carpinteri and F. Mainardi (Eds), Fractals and Fractional Calculus in Continuum Mechanics., Springer, 223-276, 1997, Wien. [14] T. Higgins, A hypergeometric function transform, SIAM J. Math. Anal., 12, (1964), 601-612. [15] A.T. James, Special Functions of Matrix and Single Argument in Statistics in Theory and Application of Special Functions., R. A. Askey (Ed) Academic Press, New York, 1975. [16] L. Jódar and J. C. Cortés, On the hypergeometric matrix function, J. Comp. Appl. Math., 99, (1998), 205-217. [17] H. L. Krall and O. Frink, A new class of orthogonal polynomials: The Bessel poly- nomials, Trans. Amer. Math. Soc., 65 (1949) 100-115. [18] J. P. Kauthen, The method of lines for parabolic partial integro-dierential equations, J.Integ. Equa. Appl., 4, (1992), 69-81. [19] M. Abdalla, On the incomplete hypergeometric matrix functions, Ramanujan J., 43, (2017), 663-678. [20] Z. Kishka, A.Shehata and M. A. Abul-Dahab, On Humbert matrix functions and their properties, Afr. Mat., 24,(2013) 615-623. [21] Z. Kishka, M. A. Saleem, M. T. Mohammed and M. Abul-Dahab, On the p and q-Appell matrix function, Southeast. Asian. Bull. Math., 36, (2012), 837-848. [22] Z. Kishka, A. Shehata and M. Abul-Dahab, The generalized Bessel matrix polynomi- als, J. Math. Comput. Sci., 2, (2012), 305-316. [23] J.L. Lavoie, T. Osler, and R. Tremblay, Fractional derivatives and special functions, SIAM Rev., 18, (1976), 240-268. [24] W. Miller, Lie Theory and Specials Functions., Academic Press, New York, (1968). [25] A. M. Mathai and H. Haubold, Special Functions for Applied Scientists., Springer Science, New York, (2008). REFERENCES 1004 [26] S. K. Miller and B. Ross, An Introduction to the Fractional Calculus and Fractional Differential Equations., John Wiley and Sons. Inc., New York 1993. [27] K. Oldham and J. Spanier, The Fractional Calculus. Academic Press, London, 1970. [28] I. Podlubny and A. M. A. El-Sayed, On two definitions of Fractional Calculus., Solvak Academy of science-institute of experimental phys. UEF-03-96 ISBN 80-7099-252-2, 1996. [29] S. Rida, H. M. El-Sherbiny, and A. A. M. Arafa, On solution of nonlinear Schrdinger equation of fractional order, Physics Letters A., 372, (2008), 553-558. [30] S. Rida and A. M. Yousef, On the fractional order Rodrigues formula for Legendre polynomials, Advanced and applications in mathematical science, 10 (2001), 509-517. [31] S. Rida, On the generalized ultraspherical or Gegenbauer functions of fractional or- ders, Appl. Math. Comput., 151 (2) (2004), 543-565. [32] S. Samko, A. Kilbas, and O. Marichev, Fractional Integrals and Derivatives: Theory and Applications., Gordon and Breach Science, New York, 1993.