Opuscula Math. 46, no. 4 (2026), 521-539
https://doi.org/10.7494/OpMath.202606121
Opuscula Mathematica
Nonlinear hybrid second-order neutral delay differential equation with mixed sign terms: Oscillation via symmetry transform
Ganesh Purushothaman
Pandarinathan Nandakumar
George E. Chatzarakis
Ethiraju Thandapani
Abstract. This paper investigates the oscillatory behavior of solutions to a class of second-order nonlinear neutral delay differential equations with both positive and negative terms of the form \[\left(a(\theta) z^{\prime}(\theta)\right)^{\prime} - p(\theta)x(\theta) + q(\theta)x^{\alpha}(\sigma(\theta)) = 0, \quad \theta \geq \theta_{0},\] where \(z(\theta) = x(\theta) + b(\theta)x(\tau(\theta))\). To facilitate the analysis, the equation is transformed, via a positive solution of an auxiliary second-order ordinary differential equation, into a binomial form. By employing the comparison and integral averaging techniques together with the arithmetic-geometric mean inequality, we establish new sufficient conditions for the oscillation of all solutions. The results obtained extend and improve several existing criteria in the literature. Finally, illustrative examples are presented to demonstrate the effectiveness, novelty, and applicability of the proposed oscillation criteria.
Keywords: oscillation, second-order, neutral, delay differential equation, symmetry transform.
Mathematics Subject Classification: 34C10, 34K11.
- A. Abdelnasen, O. Moaz, C. Cesarano, S. Askar, E.M. Elbbasy, Oscillation test for second-order differential equations with several delays, Symmetry 15 (2023), 452-462. https://doi.org/10.3390/sym15020452
- R.P. Agarwal, M. Bohner, W.T. Li, Nonoscillation and Oscillation: Theory of Functional Differential Equations, Marcel Dekker, New York, 2004. https://doi.org/10.1201/9780203025741
- R.P. Agarwal, S.R. Grace, D. O’Regan, Oscillation Theory for Second-order Linear, Halflinear, Superlinear and Sublinear Dynamic Equations, Kluwer Acad. Publ., Dordrecht, Netherlands, 2002. https://doi.org/10.1007/978-94-017-2515-6_4
- A.M. Alomain, A. Muhib, Some new oscillation results for second order differential equations with neutral term, AIMS Mathematics 10 (2025), 694-704. https://doi.org/10.3934/math.2025031
- B. Baculikova, Oscillatory criteria for second order differential equations with several sublinear neutral terms, Opuscula Math. 39 (2019), 753-763. https://doi.org/10.7494/opmath.2019.39.6.753
- B. Baculikova, Property (A) and oscillation of higher-order trinomial differential equations with retarded and advanced arguments, Mathematics 12 (2024), 1-11. https://doi.org/10.3390/math12060910
- B. Baculikova, T. Li, J. Dzurina, Oscillation theorems for second order superlinear neutral differential equations, Math. Slovaca 63 (2013), 123-134. https://doi.org/10.2478/s12175-012-0087-9
- Y. Bai, L. Liu, New oscillation criteria for second-order neutral delay differential equations with positive and negative coefficients, Abstr. Appl. Anal. 2010 (2010), 1-11. https://doi.org/10.1155/2010/564068
- D.D. Bainov, D.P. Mishev, Oscillation Theory for Neutral Differential Equations with Delay, Adam Hilger, Bristol, 1991.
- R. Bellman, K.L. Cooke, Differential-Difference Equations, Academic Press, New York, USA, 1963.
- M. Bohner, S.R. Grace, I. Jadlovska, Oscillation criteria for second order neutral delay differential equations, Electron. J. Qual. Theory Differ. Equ. 60 (2017), 1-12. https://doi.org/10.14232/ejqtde.2017.1.60
- M. Bohner, R. Srinivasan, E. Thandapani, Oscillation of second order damped noncanonical differential equations with superlinear neutral term, J. Inequal. Spec. Funct. 12 (2021), 44-53.
- M. Bohner, B. Sudha, K. Thangavelu, E. Thandapani, Oscillation criteria for second-order differential equations with superlinear neutral term, Nonlinear Stud. 26 (2019), 425-434.
- X. Deng, Q. Wang, Z. Zhou, Oscillation criteria for second-order neutral dynamic equations of Emden-Fowler type with positive and negative coefficients on time scales, Sci. China Math. 60 (2017), 113-13.
- J. Dzurina, Oscillation of second order trinomial differential equations with retarded and advanced arguments, Appl. Math. Lett. 153 (2024), 109058. https://doi.org/10.1016/j.aml.2024.109058
- J. Dzurina, S.R. Grace, I. Jadlovska, T. Li, Oscillation criteria for second order Emden-Fowler delay differential equations with a sublinear neutral term, Math. Nach. 2020 (2020), 910-922. https://doi.org/10.1002/mana.201800196
- J. Dzurina, E. Thandapani, B. Baculikova, C. Dharuman, N. Prabaharan, Oscillation of second order nonlinear differential equations with several sublinear neutral terms, Nonlinear Dyn. Syst. Theory 19 (2019), 124-132.
- I. Goyri, G. Ladas, Oscillation Theory of Delay Differential Equations with Applications, Clarendon Press, Oxford, UK, 1991. https://doi.org/10.1093/oso/9780198535829.001.0001
- S.R. Grace, G.N. Chhatria, Oscillation of higher order nonlinear dynamic equations with a nonlinear neutral term, Math. Meth. Appl. Sci. 46 (2023), 2373-2388. https://doi.org/10.1002/mma.8650
- S.R. Grace, G.N. Chhatria, New oscillation criteria for higher order nonlinear dynamic equations, Differ. Equ. Dyn. Syst. 34 (2026), 169-179. https://doi.org/10.1007/s12591-023-00674-7
- R. Guo, Q. Huang, H. Tian, Nonoscillation and oscillation criteria for a class of second-order nonlinear neutral delay differential equations with positive and negative coefficients, Axioms 281 (2022), 1-11. https://doi.org/10.3390/axioms11060281
- J.K. Hale, Theory of Functional Differential Equations, Springer, New York, 1977. https://doi.org/10.1007/978-1-4612-9892-2_3
- T. Kusano, M. Naito, Comparison theorems for functional differential equations with deviating arguments, J. Math. Soc. Japan. 33 (1981), 509-533. https://doi.org/10.2969/jmsj/03330509
- T. Kusano, J. Wang, Oscillation properties of half-linear functional differential equations of the second order, Hiroshima Math. J. 25 (1995), 371-385. https://doi.org/10.32917/hmj/1206127717
- T. Li, Y.V. Rogovchenko, Oscillation criteria for second order superlinear Emden-Fowler neutral differential equations, Monatsh. Math. 18 (2017), 489-500. https://doi.org/10.1007/s00605-017-1039-9
- O. Moaaz, A. Muhib, S. Owyed, E.E. Mahmoud, Second-order neutral differential equations: improved criteria for testing the oscillation, J. Math. 2021 (2021), 1-7. https://doi.org/10.1155/2021/6665103
- A. Nabih, A. Al-Jaser, O. Moaaz, Neutral Emden-Fowler differential equations of second order: oscillation criteria of Coles type, Symmetry 16 (2024), 931. https://doi.org/10.3390/sym16070931
- O. Ocalan, Oscillation of neutral differential equations with positive and negative coefficients, J. Math. Anal. Appl. 331 (2007), 644-654. https://doi.org/10.1016/j.jmaa.2006.09.016
- O. Ozdemir, A. Kilic, Oscillation of second order functional differential equations with superlinear neutral terms, Bull. Malays. Math. Sci. Soc. 45 (2022), 83-99. https://doi.org/10.1007/s40840-021-01185-w
- M. Ruggieri, S.S. Santra, A. Scapellato, Oscillatory behaviour of second-order neutral differential equations, Bull. Braz. Math. Soc. 53 (2022), 665-675. https://doi.org/10.1007/s00574-021-00276-3
- S. Shi, Z. Han, Oscillation of second order mixed functional differential equations with sublinear and superlinear neutral terms, Turk. J. Math. 46 (2022), 3045-3056. https://doi.org/10.55730/1300-0098.3317
- Y. Shoukaku, Oscillation of solutions of second order neutral differential equations with positive and negative coefficients, J. Appl. Anal. 15 (2009), 281-298. https://doi.org/10.1515/jaa.2009.281
- Y. Shoukaku, Oscillation criteria of second-order differential equation with positive and negative coefficients, Hacette. J. Math. Stat. 51 (2022), 970-980.
- C.A. Swansan, Comparison and Oscillation Theory of Linear Differential Equations, Academic Press, New York, 1968. https://doi.org/10.1016/s0076-5392(08)62266-3
- E. Thandapani, V. Muthulakshmi, J.R. Graef, Oscillation criteria for second-order nonlinear neutral delay differential equations with positive and negative coefficients, Int. J. Pure Appl. Math. 70 (2011), 261-274.
- A. Zafer, T. Candan, Z.N. Gurkan, Equivalence transformation for neutral differential equations: oscillation of solutions, Mathematics 13 (2025), 1-11. https://doi.org/10.3390/math13142243
- Ganesh Purushothaman
https://orcid.org/0000-0002-8709-5588- Department of Mathematics, St. Joseph's College of Engineering, Chennai-600119, India
- Pandarinathan Nandakumar
https://orcid.org/0009-0000-9463-2647- Department of Mathematics, Perunthalaivar Kamarajar Institute of Engineering and Technology (Constituent College of Puducherry Technological University), Karaikal-609603, India
- George E. Chatzarakis (corresponding author)
https://orcid.org/0000-0002-0477-1895- Department of Electrical and Electronic Engineering Educators, School of Pedagogical and Technological Education, Marousi 15122, Athens, Greece
- Ethiraju Thandapani
https://orcid.org/0000-0001-6801-4191- Ramanujan Institute for Advanced Study in Mathematics, University of Madras, Chennai-600005, India
- Communicated by Josef Diblík.
- Received: 2025-11-07.
- Revised: 2026-03-27.
- Accepted: 2026-06-12.
- Published online: 2026-08-04.

