{"title":"Entire curves generating all shapes of Nevanlinna currents","authors":"Hao Wu, Song-Yan Xie","doi":"10.1112/jlms.70177","DOIUrl":null,"url":null,"abstract":"<p>First, we show that every complex torus <span></span><math>\n <semantics>\n <mi>T</mi>\n <annotation>$\\mathbb {T}$</annotation>\n </semantics></math> contains some entire curve <span></span><math>\n <semantics>\n <mrow>\n <mi>g</mi>\n <mo>:</mo>\n <mi>C</mi>\n <mo>→</mo>\n <mi>T</mi>\n </mrow>\n <annotation>$g: \\mathbb {C}\\rightarrow \\mathbb {T}$</annotation>\n </semantics></math> such that the concentric holomorphic discs <span></span><math>\n <semantics>\n <msub>\n <mrow>\n <mo>{</mo>\n <mi>g</mi>\n <mspace></mspace>\n <msub>\n <mo>|</mo>\n <msub>\n <mover>\n <mi>D</mi>\n <mo>¯</mo>\n </mover>\n <mi>r</mi>\n </msub>\n </msub>\n <mo>}</mo>\n </mrow>\n <mrow>\n <mi>r</mi>\n <mo>></mo>\n <mn>0</mn>\n </mrow>\n </msub>\n <annotation>$\\lbrace g\\,\\vert _{\\overline{\\mathbb {D}}_{r}}\\rbrace _{r>0}$</annotation>\n </semantics></math> can generate all the Nevanlinna/Ahlfors currents on <span></span><math>\n <semantics>\n <mi>T</mi>\n <annotation>$\\mathbb {T}$</annotation>\n </semantics></math> at cohomological level. This confirms an anticipation of Sibony. Developing further our new method, we can construct some twisted entire curve <span></span><math>\n <semantics>\n <mrow>\n <mi>f</mi>\n <mo>:</mo>\n <mi>C</mi>\n <mo>→</mo>\n <msup>\n <mi>CP</mi>\n <mn>1</mn>\n </msup>\n <mo>×</mo>\n <mi>E</mi>\n </mrow>\n <annotation>$f: \\mathbb {C}\\rightarrow \\mathbb {CP}^1\\times E$</annotation>\n </semantics></math> in the product of the rational curve <span></span><math>\n <semantics>\n <msup>\n <mi>CP</mi>\n <mn>1</mn>\n </msup>\n <annotation>$\\mathbb {CP}^1$</annotation>\n </semantics></math> and an elliptic curve <span></span><math>\n <semantics>\n <mi>E</mi>\n <annotation>$E$</annotation>\n </semantics></math>, such that, concerning Siu's decomposition, demanding any cardinality <span></span><math>\n <semantics>\n <mrow>\n <mrow>\n <mo>|</mo>\n <mi>J</mi>\n <mo>|</mo>\n </mrow>\n <mo>∈</mo>\n <msub>\n <mi>Z</mi>\n <mrow>\n <mo>⩾</mo>\n <mn>0</mn>\n </mrow>\n </msub>\n <mo>∪</mo>\n <mrow>\n <mo>{</mo>\n <mi>∞</mi>\n <mo>}</mo>\n </mrow>\n </mrow>\n <annotation>$|J|\\in \\mathbb {Z}_{\\geqslant 0}\\cup \\lbrace \\infty \\rbrace$</annotation>\n </semantics></math> and that <span></span><math>\n <semantics>\n <msub>\n <mi>T</mi>\n <mi>diff</mi>\n </msub>\n <annotation>$\\mathcal {T}_{{\\rm diff}}$</annotation>\n </semantics></math> is trivial (<span></span><math>\n <semantics>\n <mrow>\n <mo>|</mo>\n <mi>J</mi>\n <mo>|</mo>\n <mo>⩾</mo>\n <mn>1</mn>\n </mrow>\n <annotation>$|J|\\geqslant 1$</annotation>\n </semantics></math>) or not (<span></span><math>\n <semantics>\n <mrow>\n <mo>|</mo>\n <mi>J</mi>\n <mo>|</mo>\n <mo>⩾</mo>\n <mn>0</mn>\n </mrow>\n <annotation>$|J|\\geqslant 0$</annotation>\n </semantics></math>), we can always find a sequence of concentric holomorphic discs <span></span><math>\n <semantics>\n <msub>\n <mrow>\n <mo>{</mo>\n <mi>f</mi>\n <mspace></mspace>\n <msub>\n <mo>|</mo>\n <msub>\n <mover>\n <mi>D</mi>\n <mo>¯</mo>\n </mover>\n <msub>\n <mi>r</mi>\n <mi>j</mi>\n </msub>\n </msub>\n </msub>\n <mo>}</mo>\n </mrow>\n <mrow>\n <mi>j</mi>\n <mo>⩾</mo>\n <mn>1</mn>\n </mrow>\n </msub>\n <annotation>$\\lbrace f\\,\\vert _{\\overline{\\mathbb {D}}_{r_j}}\\rbrace _{j \\geqslant 1}$</annotation>\n </semantics></math> to generate a Nevanlinna/Ahlfors current <span></span><math>\n <semantics>\n <mrow>\n <mi>T</mi>\n <mo>=</mo>\n <msub>\n <mi>T</mi>\n <mi>alg</mi>\n </msub>\n <mo>+</mo>\n <msub>\n <mi>T</mi>\n <mi>diff</mi>\n </msub>\n </mrow>\n <annotation>$\\mathcal {T}=\\mathcal {T}_{{\\rm alg}}+\\mathcal {T}_{{\\rm diff}}$</annotation>\n </semantics></math> with the singular part <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>T</mi>\n <mi>alg</mi>\n </msub>\n <mo>=</mo>\n <msub>\n <mo>∑</mo>\n <mrow>\n <mi>j</mi>\n <mo>∈</mo>\n <mi>J</mi>\n </mrow>\n </msub>\n <mspace></mspace>\n <msub>\n <mi>λ</mi>\n <mi>j</mi>\n </msub>\n <mo>·</mo>\n <mrow>\n <mo>[</mo>\n <msub>\n <mi>C</mi>\n <mi>j</mi>\n </msub>\n <mo>]</mo>\n </mrow>\n </mrow>\n <annotation>$\\mathcal {T}_{{\\rm alg}}=\\sum _{j\\in J} \\,\\lambda _j\\cdot [\\mathsf {C}_j]$</annotation>\n </semantics></math> in the desired shape. This fulfills the missing case where <span></span><math>\n <semantics>\n <mrow>\n <mo>|</mo>\n <mi>J</mi>\n <mo>|</mo>\n <mo>=</mo>\n <mn>0</mn>\n </mrow>\n <annotation>$|J|=0$</annotation>\n </semantics></math> in the previous work of Huynh–Xie. By a result of Duval, each <span></span><math>\n <semantics>\n <msub>\n <mi>C</mi>\n <mi>j</mi>\n </msub>\n <annotation>$\\mathsf {C}_j$</annotation>\n </semantics></math> must be rational or elliptic. We will show that there is no <i>a priori</i> restriction on the numbers of rational and elliptic components in the support of <span></span><math>\n <semantics>\n <msub>\n <mi>T</mi>\n <mi>alg</mi>\n </msub>\n <annotation>$\\mathcal {T}_{{\\rm alg}}$</annotation>\n </semantics></math>, thus answering a question of Yau and Zhou. Moreover, we will show that the positive coefficients <span></span><math>\n <semantics>\n <msub>\n <mrow>\n <mo>{</mo>\n <msub>\n <mi>λ</mi>\n <mi>j</mi>\n </msub>\n <mo>}</mo>\n </mrow>\n <mrow>\n <mi>j</mi>\n <mo>∈</mo>\n <mi>J</mi>\n </mrow>\n </msub>\n <annotation>$\\lbrace \\lambda _j\\rbrace _{j\\in J}$</annotation>\n </semantics></math> can be arbitrary as long as the total mass of <span></span><math>\n <semantics>\n <msub>\n <mi>T</mi>\n <mi>alg</mi>\n </msub>\n <annotation>$\\mathcal {T}_{{\\rm alg}}$</annotation>\n </semantics></math> is less than or equal to 1.</p>","PeriodicalId":49989,"journal":{"name":"Journal of the London Mathematical Society-Second Series","volume":"111 5","pages":""},"PeriodicalIF":1.0000,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the London Mathematical Society-Second Series","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1112/jlms.70177","RegionNum":2,"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
First, we show that every complex torus contains some entire curve such that the concentric holomorphic discs can generate all the Nevanlinna/Ahlfors currents on at cohomological level. This confirms an anticipation of Sibony. Developing further our new method, we can construct some twisted entire curve in the product of the rational curve and an elliptic curve , such that, concerning Siu's decomposition, demanding any cardinality and that is trivial () or not (), we can always find a sequence of concentric holomorphic discs to generate a Nevanlinna/Ahlfors current with the singular part in the desired shape. This fulfills the missing case where in the previous work of Huynh–Xie. By a result of Duval, each must be rational or elliptic. We will show that there is no a priori restriction on the numbers of rational and elliptic components in the support of , thus answering a question of Yau and Zhou. Moreover, we will show that the positive coefficients can be arbitrary as long as the total mass of is less than or equal to 1.
期刊介绍:
The Journal of the London Mathematical Society has been publishing leading research in a broad range of mathematical subject areas since 1926. The Journal welcomes papers on subjects of general interest that represent a significant advance in mathematical knowledge, as well as submissions that are deemed to stimulate new interest and research activity.