In this article, we derived conditions on the order $ \nu $ of the classical Bessel functions $ J_{\nu} $ that guarantee the inclusion of three distinct normalized forms of $ J_{\nu} $ in a subclass of $ \alpha $-spirallike functions. The primary goal was to determine the subintervals within $ (-\frac{\pi}{2}, \frac{\pi}{2}) $ where these inclusion conditions are satisfied. A key component in establishing our results was the upper bound of the ratio $ J_{\nu+1}(1)/J_{\nu}(1) $. The theoretical findings were validated through numerical experiments and accompanying graphical demonstrations.
Citation: Saiful Rahman Mondal, Ahlam Almulhim. Inclusion of Bessel functions in a subclass of spiral functions[J]. AIMS Mathematics, 2025, 10(8): 17362-17380. doi: 10.3934/math.2025776
In this article, we derived conditions on the order $ \nu $ of the classical Bessel functions $ J_{\nu} $ that guarantee the inclusion of three distinct normalized forms of $ J_{\nu} $ in a subclass of $ \alpha $-spirallike functions. The primary goal was to determine the subintervals within $ (-\frac{\pi}{2}, \frac{\pi}{2}) $ where these inclusion conditions are satisfied. A key component in establishing our results was the upper bound of the ratio $ J_{\nu+1}(1)/J_{\nu}(1) $. The theoretical findings were validated through numerical experiments and accompanying graphical demonstrations.
| [1] | P. L. Duren, Univalent functions, Vol. 259, New York: Springer-Verlag, 1983. |
| [2] | F. Rønning, Uniformly convex functions and a corresponding class of starlike functions, Proc. Amer. Math. Soc., 118 (1993), 189–196. |
| [3] |
R. M. Ali, Starlikeness associated with parabolic regions, Int. J. Math. Math. Sci., 4 (2005), 561–570. https://doi.org/10.1155/IJMMS.2005.561 doi: 10.1155/IJMMS.2005.561
|
| [4] | A. W. Goodman, Univalent functions, Vol. Ⅰ, Mariner Publishing Co., Inc., 1983. |
| [5] |
Y. C. Kim, T. Sugawa, Correspondence between spirallike functions and starlike functions, Math. Nachr., 285 (2012), 322–331. https://doi.org/10.1002/mana.201010020 doi: 10.1002/mana.201010020
|
| [6] |
R. J. Libera, Univalent $\alpha $-spiral functions, Can. J. Math., 19 (1967), 449–456. https://doi.org/10.4153/CJM-1967-038-0 doi: 10.4153/CJM-1967-038-0
|
| [7] | V. Ravichandran, C. Selvaraj, R. Rajagopal, On uniformly convex spiral functions and uniformly spirallike functions, Soochow J. Math., 29 (2003), 393–405. |
| [8] |
N. Alabkary, S. R. Mondal, On spirallikeness of entire functions, Mathematics, 13 (2025), 1566. https://doi.org/10.3390/math13101566 doi: 10.3390/math13101566
|
| [9] | G. N. Watson, A treatise on the theory of Bessel functions, 2 Eds., Cambridge University Press, 1944. |
| [10] | D. K. Ross, Inequalities for special functions, SIAM Rev., 15 (1973), 665–670. |
| [11] |
E. K. Ifantis, P. D. Siafarikas, Inequalities involving Bessel and modified Bessel functions, J. Math. Anal. Appl., 147 (1990), 214–227. https://doi.org/10.1016/0022-247X(90)90394-U doi: 10.1016/0022-247X(90)90394-U
|
| [12] |
R. K. Brown, Univalence of Bessel functions, Proc. Amer. Math. Soc., 11 (1960), 278–283. https://doi.org/10.2307/2032969 doi: 10.2307/2032969
|
| [13] | R. K. Brown, Univalent solutions of $W^{\prime\prime}+pW = 0$, Can. J. Math., 14 (1962), 69–78. |
| [14] |
R. K. Brown, Univalence of normalized solutions of $W^{\prime\prime}(z)+p(z)W(z) = 0$, Int. J. Math. Math. Sci., 5 (1982), 459–483. https://doi.org/10.1155/S0161171282000441 doi: 10.1155/S0161171282000441
|
| [15] | E. Kreyszig, J. Todd, The radius of univalence of Bessel functions Ⅰ, Illinois J. Math., 4 (1960), 143–149. |
| [16] | A. Baricz, Geometric properties of generalized Bessel functions, Publ. Math. Debrecen, 73 (2008), 155–178. |
| [17] | A. Baricz, Geometric properties of generalized Bessel functions of complex order, Mathematica, 48 (2006), 13–18. |
| [18] |
S. Kanas, S. R. Mondal, A. D. Mohammed, Relations between the generalized Bessel functions and the Janowski class, Math. Inequal. Appl., 21 (2018), 165–178. https://doi.org/10.7153/mia-2018-21-14 doi: 10.7153/mia-2018-21-14
|
| [19] | S. R. Mondal, A. Swaminathan, Geometric properties of generalized Bessel functions, Bull. Malays. Math. Sci. Soc., 35 (2012), 179–194. |
| [20] |
N. Bohra, V. Ravichandran, Radii problems for normalized Bessel functions of first kind, Comput. Methods Funct. Theory, 18 (2018), 99–123. https://doi.org/10.1007/s40315-017-0216-0 doi: 10.1007/s40315-017-0216-0
|
| [21] |
V. Madaan, A. Kumar, V. Ravichandran, Starlikeness associated with lemniscate of Bernoulli, Filomat, 33 (2019), 1937–1955. https://doi.org/10.2298/FIL1907937M doi: 10.2298/FIL1907937M
|
| [22] |
A. Baricz, R. Szász, The radius of convexity of normalized Bessel functions of the first kind, Anal. Appl., 12 (2014), 485–509. https://doi.org/10.1142/S0219530514500316 doi: 10.1142/S0219530514500316
|
| [23] |
I. Aktaş, A. Baricz, H. Orhan, Bounds for radii of starlikeness and convexity of some special functions, Turk. J. Math., 42 (2018), 211–226. https://doi.org/10.3906/mat-1610-41 doi: 10.3906/mat-1610-41
|
| [24] |
I. Aktaş, E. Toklu, H. Orhan, Radii of uniform convexity of some special functions, Turk. J. Math., 42 (2018), 3010–3024. https://doi.org/10.3906/mat-1806-43 doi: 10.3906/mat-1806-43
|
| [25] |
E. Deniz, R. Szász, The radius of uniform convexity of Bessel functions, J. Math. Anal. Appl., 453 (2017), 572–588. https://doi.org/10.1016/j.jmaa.2017.03.079 doi: 10.1016/j.jmaa.2017.03.079
|
| [26] |
S. Kanas, K. Gangania, Radius of uniformly convex $\gamma$-spirallikeness of combination of derivatives of Bessel functions, Axioms, 12 (2023), 468. https://doi.org/10.3390/axioms12050468 doi: 10.3390/axioms12050468
|