We studied deferred weighted statistical and modular convergence generated by admissible lower triangular transformations. Let $ A = (a_{nk})_{n, k\geq0} $ be a triangle with nonzero diagonal entries, uniformly bounded absolute row sums, and null columns. Convergence is defined through the transformed sequence $ Ax $ along admissible deferred weighted windows. We proved that the column-null condition is equivalent to $ A(\varphi)\subseteq c_0 $, where $ \varphi $ denotes the space of finitely supported sequences, and use this characterization to obtain stability under finite modifications. We established uniqueness, linearity, strong-to-statistical implications, bounded converses, Cauchy characterizations, ideal and Musielak–Orlicz extensions, and window-comparison results. Analogous results are obtained for separable transformations of double sequences. As an application, we showed that the fractional $ q $-difference triangle $ Q^{(q, \xi)} $ has an $ \ell_1 $ coefficient kernel, uniformly bounded absolute row sums, and null fixed columns. Integer orders yield banded triangles, whereas noninteger orders produce nonterminating but absolutely summable kernels.
Citation: Gui-Ying Weng, Ömer Kişi, Mehmet Gürdal, Qing-Bo Cai. Deferred weighted statistical and modular convergence generated by admissible lower triangular transformations: fractional $ q $-difference applications[J]. AIMS Mathematics, 2026, 11(7): 23404-23436. doi: 10.3934/math.2026944
We studied deferred weighted statistical and modular convergence generated by admissible lower triangular transformations. Let $ A = (a_{nk})_{n, k\geq0} $ be a triangle with nonzero diagonal entries, uniformly bounded absolute row sums, and null columns. Convergence is defined through the transformed sequence $ Ax $ along admissible deferred weighted windows. We proved that the column-null condition is equivalent to $ A(\varphi)\subseteq c_0 $, where $ \varphi $ denotes the space of finitely supported sequences, and use this characterization to obtain stability under finite modifications. We established uniqueness, linearity, strong-to-statistical implications, bounded converses, Cauchy characterizations, ideal and Musielak–Orlicz extensions, and window-comparison results. Analogous results are obtained for separable transformations of double sequences. As an application, we showed that the fractional $ q $-difference triangle $ Q^{(q, \xi)} $ has an $ \ell_1 $ coefficient kernel, uniformly bounded absolute row sums, and null fixed columns. Integer orders yield banded triangles, whereas noninteger orders produce nonterminating but absolutely summable kernels.
| [1] |
R. P. Agnew, On deferred Cesàro means, Ann. Math., 33 (1932), 413–421. https://doi.org/10.2307/1968524 doi: 10.2307/1968524
|
| [2] | F. Başar, Summability theory and its applications 2 Eds., New York: Chapman and Hall/CRC, 2022. https://doi.org/10.1201/9781003294153 |
| [3] |
J. S. Connor, The statistical and strong $ p $-Cesàro convergence of sequences, Analysis, 8 (1988), 47–64. https://doi.org/10.1524/anly.1988.8.12.47 doi: 10.1524/anly.1988.8.12.47
|
| [4] | İ. Dağadur, Ş. Sezgek, Deferred Cesàro mean and deferred statistical convergence of double sequences, J. Inequal. Spec. Funct., 7 (2016), 118–136. |
| [5] | M. Et, R. Çolak, On some generalized difference sequence spaces, Soochow J. Math., 21 (1995), 377–386. |
| [6] | H. Fast, Sur la convergence statistique, Colloq. Math., 2 (1951), 241–244. |
| [7] | J. A. Fridy, On statistical convergence, Analysis, 5 (1985), 301–313. https://doi.org/10.1524/anly.1985.5.4.301 |
| [8] | V. Kac, P. Cheung, Quantum calculus, New York: Springer, 2002. https://doi.org/10.1007/978-1-4613-0071-7 |
| [9] | H. Kızmaz, On certain sequence spaces, Can. Math. Bull., 24 (1981), 169–176. https://doi.org/10.4153/CMB-1981-027-5 |
| [10] | P. Kostyrko, T. Šalát, W. Wilczyński, $ \mathcal I $-Convergence, Real Anal. Exch., 26 (1999), 193–200. |
| [11] | M. A. Krasnosel'skii, Y. B. Rutickii, Convex functions and Orlicz spaces, New York: Gordon & Breach, 1961. |
| [12] |
M. Küçükaslan, M. Yılmaztürk, On deferred statistical convergence of sequences, Kyungpook Math. J., 56 (2016), 357–366. https://doi.org/10.5666/KMJ.2016.56.2.357 doi: 10.5666/KMJ.2016.56.2.357
|
| [13] |
F. Móricz, Statistical convergence of multiple sequences, Arch. Math., 81 (2003), 82–89. https://doi.org/10.1007/s00013-003-0506-9 doi: 10.1007/s00013-003-0506-9
|
| [14] | M. Mursaleen, F. Başar, Sequence spaces: topics in modern summability theory, Boca Raton: CRC Press, 2020. https://doi.org/10.1201/9781003015116 |
| [15] |
M. Mursaleen, O. H. H. Edely, Statistical convergence of double sequences, J. Math. Anal. Appl., 288 (2003), 223–231. https://doi.org/10.1016/j.jmaa.2003.08.004 doi: 10.1016/j.jmaa.2003.08.004
|
| [16] | J. Musielak, Orlicz spaces and modular spaces, Berlin: Springer, 1983. https://doi.org/10.1007/BFb0072210 |
| [17] | W. Orlicz, Über Räume $ (L^M) $, Bull. Acad. Polonaise A, 1936 (1936), 93–107. |
| [18] |
A. Pringsheim, Zur theorie der zweifach unendlichen zahlenfolgen, Math. Ann., 53 (1900), 289–321. https://doi.org/10.1007/BF01448977 doi: 10.1007/BF01448977
|
| [19] | H. Steinhaus, Sur la convergence ordinaire et la convergence asymptotique, Colloq. Math., 2 (1951), 73–74. |