{"title":"New monotonicity properties and oscillation of $n$-order functional differential equations with deviating argument","authors":"B. Baculíková","doi":"10.14232/ejqtde.2023.1.30","DOIUrl":null,"url":null,"abstract":"<jats:p>In this paper, we offer new technique for investigation of the even order linear differential equations of the form <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" xmlns=\"http://www.w3.org/1998/Math/MathML\" display=\"block\"> <mml:mtable displaystyle=\"true\"> <mml:mlabeledtr> <mml:mtd id=\"mjx-eqn-E\"> <mml:mrow> <mml:mtext>(</mml:mtext> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi>E</mml:mi> </mml:mrow> <mml:mtext>)</mml:mtext> </mml:mrow> </mml:mtd> <mml:mtd> <mml:msup> <mml:mi>y</mml:mi> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>n</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> </mml:mrow> </mml:msup> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>t</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mo>=</mml:mo> <mml:mi>p</mml:mi> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>t</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mi>y</mml:mi> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>τ<!-- τ --></mml:mi> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>t</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mo>.</mml:mo> </mml:mtd> </mml:mlabeledtr> </mml:mtable> </mml:math> We establish new criteria for bounded and unbounded oscillation of <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" xmlns=\"http://www.w3.org/1998/Math/MathML\"> <mml:mrow class=\"MathJax_ref\" href=\"#mjx-eqn-E\"> <mml:mrow> <mml:mtext>(</mml:mtext> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi>E</mml:mi> </mml:mrow> <mml:mtext>)</mml:mtext> </mml:mrow> </mml:mrow> </mml:math> which improve a number of related ones in the literature. Our approach essentially involves establishing stronger monotonicities for the positive solutions of <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" xmlns=\"http://www.w3.org/1998/Math/MathML\"> <mml:mrow class=\"MathJax_ref\" href=\"#mjx-eqn-E\"> <mml:mrow> <mml:mtext>(</mml:mtext> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi>E</mml:mi> </mml:mrow> <mml:mtext>)</mml:mtext> </mml:mrow> </mml:mrow> </mml:math> than those presented in known works. We illustrate the improvement over known results by applying and comparing our technique with the other known methods on the particular examples.</jats:p>","PeriodicalId":50537,"journal":{"name":"Electronic Journal of Qualitative Theory of Differential Equations","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electronic Journal of Qualitative Theory of Differential Equations","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.14232/ejqtde.2023.1.30","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, we offer new technique for investigation of the even order linear differential equations of the form (E)y(n)(t)=p(t)y(τ(t)). We establish new criteria for bounded and unbounded oscillation of (E) which improve a number of related ones in the literature. Our approach essentially involves establishing stronger monotonicities for the positive solutions of (E) than those presented in known works. We illustrate the improvement over known results by applying and comparing our technique with the other known methods on the particular examples.
本文给出了研究形式为(E) y (n) (t) = p (t) y (τ (t))的偶阶线性微分方程的新方法。我们建立了(E)的有界和无界振荡的新判据,改进了文献中有关的判据。我们的方法本质上涉及建立(E)的正解比已知作品中提出的更强的单调性。我们通过将我们的技术与其他已知方法在特定示例上的应用和比较来说明对已知结果的改进。
期刊介绍:
The Electronic Journal of Qualitative Theory of Differential Equations (EJQTDE) is a completely open access journal dedicated to bringing you high quality papers on the qualitative theory of differential equations. Papers appearing in EJQTDE are available in PDF format that can be previewed, or downloaded to your computer. The EJQTDE is covered by the Mathematical Reviews, Zentralblatt and Scopus. It is also selected for coverage in Thomson Reuters products and custom information services, which means that its content is indexed in Science Citation Index, Current Contents and Journal Citation Reports. Our journal has an impact factor of 1.827, and the International Standard Serial Number HU ISSN 1417-3875.
All topics related to the qualitative theory (stability, periodicity, boundedness, etc.) of differential equations (ODE''s, PDE''s, integral equations, functional differential equations, etc.) and their applications will be considered for publication. Research articles are refereed under the same standards as those used by any journal covered by the Mathematical Reviews or the Zentralblatt (blind peer review). Long papers and proceedings of conferences are accepted as monographs at the discretion of the editors.