Enhanced L1-Convergence Theorems for Modified Cosine and Sine Series
DOI:
https://doi.org/10.31305/rrijm2025.v05.n04.012Keywords:
Cosine Series, Sine Series, Trigonometric Sums, Convergence TheoremsAbstract
This paper builds on previous research that examined the L1-convergence of modified sine and cosine series. We demonstrate enhanced convergence theorems that expand and extend previous results in this domain by incorporating particular novel types of coefficients. The analysis employs summability techniques and revised inequalities to enhance the sufficient requirements for L1-convergence of trigonometric series. These results not only validate previously established theorems but also establish a foundation for a broader framework applicable to an expanded class of modified trigonometric sums. Our findings illuminate the dynamics of convergence in Fourier-type expansions and propose novel avenues for investigation in harmonic analysis and approximation theory.
References
Alzubaidi, Yassin. (2023). Sufficient Conditions for Convergence of Sequences of Henstock-Kurzweil Integrable Functions. International Journal of Analysis and Applications. 21. 49. 10.28924/2291-8639-21-2023-49. DOI: https://doi.org/10.28924/2291-8639-21-2023-49
El-Bayeh, Claude. (2012). Introduction to the General Trigonometry in Euclidian 2D-space. WSEAS Transactions on Mathematics. 11.
Gane, Samb & Lo, And & Aladji, Babacar & Niang, Aladji & Samb, Lo & Lerstad, Lo & Niang, Babacar. (2021). A NOTE ON THE WEAK CONVERGENCE OF CONTINUOUSLY INTEGRABLE SEQUENCES.
Grigoryan, M. & Sargsyan, S.. (2018). On the L1-convergence and behavior of coefficients of Fourier–Vilenkin series. Positivity. 22. 10.1007/s11117-018- 0552-y. DOI: https://doi.org/10.1007/s11117-018-0552-y
Kaur, Jatinderdeep & Bhatia, satvinder. (2011). Integrability and $L^1$-Convergence of Double Cosine Trigonometric Series. Analysis in Theory and Applications. 27. 32-39. 10.1007/s10496-011-0032-8. DOI: https://doi.org/10.1007/s10496-011-0032-8
Nagpal, Priyanka & Singh, Karanvir. (2024). Integrability and convergence of modified sum under some generalized coefficient class in L1-metric. Gulf Journal of Mathematics. 16. 313-321. 10.56947/gjom.v16i2.1830. DOI: https://doi.org/10.56947/gjom.v16i2.1830
Niculescu, Constantin & Popovici, Florin. (2013). The Asymptotic Behavior of Integrable Functions. Real Analysis Exchange. 38. 10.14321/realanalexch.38.1.0157. DOI: https://doi.org/10.14321/realanalexch.38.1.0157
Racca, Abraham & Cabral, Emmanuel. (2016). On the double Lusin condition and convergence theorem for Kurzweil-Henstock type integrals. Mathematica Bohemica. 141. 153-168. 10.21136/MB.2016.13. DOI: https://doi.org/10.21136/MB.2016.13
Rahmani-andebili, Mehdi. (2024). Fourier Series, Half-Domain Fourier Sine and Cosine Series, Complex Fourier Series, Fourier Integral, Complex Fourier Integral, Fourier Transform, and Half-Domain Fourier Sine and Cosine Transforms: Problems. 10.1007/978-3-031-71934-9_9. DOI: https://doi.org/10.1007/978-3-031-71934-9_9
Sabiri, Noureddine & Guessous, Mohamed. (2020). Convergence of Weak*- Scalarly Integrable Functions. Axioms. 9. 112. 10.3390/axioms9030112 DOI: https://doi.org/10.3390/axioms9030112
Trench, William. (1988). Asymptotic Integration of a Perturbed Constant Coefficient Differential Equation under Mild Integral Smallness Conditions. Siam Journal on Mathematical Analysis - SIAM J MATH ANAL. 19. 10.1137/0519031. DOI: https://doi.org/10.1137/0519031
Weisz, Ferenc. (2004). Summation of Fourier series. Acta Mathematica Academiae Paedagogicae Nyíregyháziensis. New Series [electronic only]. 20.
Ye, Aoshuang & Li, Yichao & Xu, Dong & Wu, Zhiwei & Chen, Guohua & Tang, Junjie & Zhu, Zhiyuan. (2024). A hybrid algorithm based on improved sine cosine algorithm and population incremental learning and its application to economic load dispatch in power systems. AIMS Energy. 12. 1294-1333. 10.3934/energy.2024059. DOI: https://doi.org/10.3934/energy.2024059
Yu, Dansheng & Zhou, Songping. (2007). On Lp Integrability and Convergence of Trigonometric Series. Studia Mathematica - STUD MATH. 182. 215-226. 10.4064/sm182-3-3. DOI: https://doi.org/10.4064/sm182-3-3