{"title":"Further study on the Brück conjecture and some non-linear complex differential equations","authors":"D. C. Pramanik, Kapil Roy","doi":"10.1108/AJMS-08-2020-0047","DOIUrl":null,"url":null,"abstract":"<jats:sec><jats:title content-type=\"abstract-subheading\">Purpose</jats:title><jats:p>The purpose of this current paper is to deal with the study of non-constant entire solutions of some non-linear complex differential equations in connection to Brück conjecture, by using the theory of complex differential equation. The results generalize the results due to Pramanik <jats:italic>et al.</jats:italic></jats:p></jats:sec><jats:sec><jats:title content-type=\"abstract-subheading\">Design/methodology/approach</jats:title><jats:p>39B32, 30D35.</jats:p></jats:sec><jats:sec><jats:title content-type=\"abstract-subheading\">Findings</jats:title><jats:p>In the current paper, we mainly study the Brück conjecture and the various works that confirm this conjecture. In our study we find that the conjecture can be generalized for differential monomials under some additional conditions and it generalizes some works related to the conjecture. Also we can take the complex number <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mi>a</m:mi></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047901.tif\" /></jats:inline-formula> in the conjecture to be a small function. More precisely, we obtain a result which can be restate in the following way: Let <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mi>f</m:mi></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047902.tif\" /></jats:inline-formula> be a non-constant entire function such that <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:msub><m:mi>σ</m:mi><m:mn>2</m:mn></m:msub><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow><m:mo><</m:mo><m:mi>∞</m:mi></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047903.tif\" /></jats:inline-formula>, <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:msub><m:mi>σ</m:mi><m:mn>2</m:mn></m:msub><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047904.tif\" /></jats:inline-formula> is not a positive integer and <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>δ</m:mi><m:mrow><m:mo stretchy=\"true\">(</m:mo><m:mrow><m:mn>0</m:mn><m:mo>,</m:mo><m:mtext> </m:mtext><m:mi>f</m:mi></m:mrow><m:mo stretchy=\"true\">)</m:mo></m:mrow><m:mo>></m:mo><m:mn>0</m:mn></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047905.tif\" /></jats:inline-formula>. Let <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>M</m:mi><m:mrow><m:mo stretchy=\"false\">[</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">]</m:mo></m:mrow></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047906.tif\" /></jats:inline-formula> be a differential monomial of <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mi>f</m:mi></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047907.tif\" /></jats:inline-formula> of degree <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:msub><m:mi>γ</m:mi><m:mi>M</m:mi></m:msub></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047908.tif\" /></jats:inline-formula> and <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>α</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>z</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow><m:mo>,</m:mo><m:mtext> </m:mtext><m:mi>β</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>z</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow><m:mo>∈</m:mo><m:mi>S</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047909.tif\" /></jats:inline-formula> be such that <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>max</m:mi><m:mrow><m:mo stretchy=\"true\">{</m:mo><m:mrow><m:mi>σ</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>α</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow><m:mo>,</m:mo><m:mtext> </m:mtext><m:mi>σ</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>β</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow></m:mrow><m:mo stretchy=\"true\">}</m:mo></m:mrow><m:mo> </m:mo><m:mo><</m:mo><m:mi>σ</m:mi><m:mrow><m:mo stretchy=\"false\">(</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">)</m:mo></m:mrow></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047910.tif\" /></jats:inline-formula>. If <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>M</m:mi><m:mrow><m:mo stretchy=\"false\">[</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">]</m:mo></m:mrow><m:mo>+</m:mo><m:mi>β</m:mi></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047911.tif\" /></jats:inline-formula> and <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:msup><m:mi>f</m:mi><m:mrow><m:msub><m:mi>γ</m:mi><m:mi>M</m:mi></m:msub></m:mrow></m:msup><m:mo>−</m:mo><m:mi>α</m:mi></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047912.tif\" /></jats:inline-formula> share the value 0 CM, then <jats:disp-formula><jats:alternatives><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mfrac><m:mrow><m:mi>M</m:mi><m:mrow><m:mo stretchy=\"false\">[</m:mo><m:mi>f</m:mi><m:mo stretchy=\"false\">]</m:mo></m:mrow><m:mo>+</m:mo><m:mi>β</m:mi></m:mrow><m:mrow><m:msup><m:mi>f</m:mi><m:mrow><m:msub><m:mi>γ</m:mi><m:mi>M</m:mi></m:msub></m:mrow></m:msup><m:mo>−</m:mo><m:mi>α</m:mi></m:mrow></m:mfrac><m:mo>=</m:mo><m:mi>c</m:mi><m:mtext>,</m:mtext></m:mrow></m:math><jats:graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047913.tif\" /></jats:alternatives></jats:disp-formula>where <jats:inline-formula><m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"><m:mrow><m:mi>c</m:mi><m:mo>≠</m:mo><m:mn>0</m:mn></m:mrow></m:math><jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"AJMS-08-2020-0047914.tif\" /></jats:inline-formula> is a constant.</jats:p></jats:sec><jats:sec><jats:title content-type=\"abstract-subheading\">Originality/value</jats:title><jats:p>This is an original work of the authors.</jats:p></jats:sec>","PeriodicalId":36840,"journal":{"name":"Arab Journal of Mathematical Sciences","volume":" ","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2020-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Arab Journal of Mathematical Sciences","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1108/AJMS-08-2020-0047","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Mathematics","Score":null,"Total":0}
引用次数: 0
Abstract
PurposeThe purpose of this current paper is to deal with the study of non-constant entire solutions of some non-linear complex differential equations in connection to Brück conjecture, by using the theory of complex differential equation. The results generalize the results due to Pramanik et al.Design/methodology/approach39B32, 30D35.FindingsIn the current paper, we mainly study the Brück conjecture and the various works that confirm this conjecture. In our study we find that the conjecture can be generalized for differential monomials under some additional conditions and it generalizes some works related to the conjecture. Also we can take the complex number a in the conjecture to be a small function. More precisely, we obtain a result which can be restate in the following way: Let f be a non-constant entire function such that σ2(f)<∞, σ2(f) is not a positive integer and δ(0,f)>0. Let M[f] be a differential monomial of f of degree γM and α(z),β(z)∈S(f) be such that max{σ(α),σ(β)}<σ(f). If M[f]+β and fγM−α share the value 0 CM, then M[f]+βfγM−α=c,where c≠0 is a constant.Originality/valueThis is an original work of the authors.