{"title":"Effects of degeneracy and functional response on the bifurcation and positive solutions for a diffusion model","authors":"Yunfeng Jia, Jingjing Wang, Jianhua Wu","doi":"10.1002/mana.70094","DOIUrl":"https://doi.org/10.1002/mana.70094","url":null,"abstract":"<p>This paper studies a diffusive competition model with degeneracy and Holling-II functional response in spatially heterogeneous environment. First, we discuss the structures and stability of steady-state bifurcation solutions. Then, the existence, nonexistence, and multiplicity of steady-state solutions are established. We conclude that there exist two critical values induced by the spatial degeneracy and the functional response, respectively, such that when the growth rate of one of the competition species is between these two critical values, the model behaves drastically and some qualitative changes occur, which is in sharp contrast to the well-studied classical models. In addition, it is found that the boundary condition also has important effects on the critical value. These show that not only degeneracy but also the combination of functional response and boundary condition have important influences on the model, especially on the structures of bifurcations and the existence of steady-state solutions. Finally, the asymptotic behavior and global attractor of positive solutions for the parabolic system are investigated, which enrich the study of dynamical behavior for the model.</p>","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 2","pages":"397-432"},"PeriodicalIF":0.8,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146136196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A note on the Brill–Noether loci of small codimension in moduli space of stable bundles","authors":"Pritthijit Biswas, Jaya N. N. Iyer","doi":"10.1002/mana.70101","DOIUrl":"https://doi.org/10.1002/mana.70101","url":null,"abstract":"<p>Let <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math> be a smooth projective curve of genus <span></span><math>\u0000 <semantics>\u0000 <mi>g</mi>\u0000 <annotation>$g$</annotation>\u0000 </semantics></math> over the field <span></span><math>\u0000 <semantics>\u0000 <mi>C</mi>\u0000 <annotation>$mathbb {C}$</annotation>\u0000 </semantics></math>. Let <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>X</mi>\u0000 </msub>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>,</mo>\u0000 <mi>L</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$M_{X}(2,L)$</annotation>\u0000 </semantics></math> denote the moduli space of stable rank 2 vector bundles on <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotation>\u0000 </semantics></math> with fixed determinant <span></span><math>\u0000 <semantics>\u0000 <mi>L</mi>\u0000 <annotation>$L$</annotation>\u0000 </semantics></math> of degree <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 <mi>g</mi>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <annotation>$2g-1$</annotation>\u0000 </semantics></math>. Consider the Brill–Noether subvariety <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>W</mi>\u0000 <mi>X</mi>\u0000 <mn>1</mn>\u0000 </msubsup>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>,</mo>\u0000 <mi>L</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$W^{1}_{X}(2,L)$</annotation>\u0000 </semantics></math> of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>X</mi>\u0000 </msub>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>,</mo>\u0000 <mi>L</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$M_{X}(2,L)$</annotation>\u0000 </semantics></math> which parameterizes stable vector bundles having at least two linearly independent global sections. In this paper, for generic <span></span><math>\u0000 <semantics>\u0000 <mi>X</mi>\u0000 <annotation>$X$</annotat","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 2","pages":"480-489"},"PeriodicalIF":0.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146140189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Generalized Campanato space over non-homogeneous space and its applications","authors":"Yuxun Zhang, Jiang Zhou","doi":"10.1002/mana.70098","DOIUrl":"https://doi.org/10.1002/mana.70098","url":null,"abstract":"<p>The authors introduce generalized Campanato space with regularized condition over non-homogeneous space, and study its basic properties including the John–Nirenberg inequality and equivalent characterizations. As applications, the boundedness of fractional type Marcinkiewicz integral and its commutator on generalized Morrey space over non-homogeneous space is obtained.</p>","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 1","pages":"270-289"},"PeriodicalIF":0.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fractional Volterra-type operators from Bergman spaces to Hardy spaces","authors":"Xiang Fang, Feng Guo, Shengzhao Hou, Xiaolin Zhu","doi":"10.1002/mana.70095","DOIUrl":"https://doi.org/10.1002/mana.70095","url":null,"abstract":"<p>A new family of Volterra-type operators <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>V</mi>\u0000 <mrow>\u0000 <mi>α</mi>\u0000 <mo>,</mo>\u0000 <mi>β</mi>\u0000 </mrow>\u0000 <mi>φ</mi>\u0000 </msubsup>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mo>·</mo>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$mathfrak {V}_{alpha,beta }^{varphi }(cdot)$</annotation>\u0000 </semantics></math> based on bona fide fractional calculus is introduced in [12] by constructing analytic paraproducts acting on <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>H</mi>\u0000 <mo>(</mo>\u0000 <mi>D</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$H(mathbb {D})$</annotation>\u0000 </semantics></math> and their boundedness between Hardy spaces is characterized for certain parameter ranges there. This paper is a natural companion to [12] in the sense that it characterizes those <span></span><math>\u0000 <semantics>\u0000 <mi>φ</mi>\u0000 <annotation>$varphi$</annotation>\u0000 </semantics></math>’s such that <span></span><math>\u0000 <semantics>\u0000 <msubsup>\u0000 <mi>V</mi>\u0000 <mrow>\u0000 <mi>α</mi>\u0000 <mo>,</mo>\u0000 <mi>β</mi>\u0000 </mrow>\u0000 <mi>φ</mi>\u0000 </msubsup>\u0000 <annotation>$mathfrak {V}_{alpha,beta }^{varphi }$</annotation>\u0000 </semantics></math> is bounded from weighted Bergman spaces <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>L</mi>\u0000 <mi>a</mi>\u0000 <mi>p</mi>\u0000 </msubsup>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>d</mi>\u0000 <msub>\u0000 <mi>A</mi>\u0000 <mi>γ</mi>\u0000 </msub>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$L_a^p(dA_gamma)$</annotation>\u0000 </semantics></math> to Hardy spaces <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>H</mi>\u0000 <mi>q</mi>\u0000 </msup>\u0000 <annotation>$H^q$</annotation>\u0000 </semantics></math> for the range\u0000\u0000 </p>","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 1","pages":"224-247"},"PeriodicalIF":0.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145930826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Zeta functions of quadratic lattices of a hyperbolic plane","authors":"Daejun Kim, Seok Hyeong Lee, Seungjai Lee","doi":"10.1002/mana.70102","DOIUrl":"https://doi.org/10.1002/mana.70102","url":null,"abstract":"<p>In this paper, we study the Dirichlet series that enumerates proper equivalence classes of full-rank sublattices of a given quadratic lattice in a hyperbolic plane—that is, a nondegenerate isotropic quadratic space of dimension 2. We derive explicit formulas for the associated zeta functions and obtain a combinatorial way to compute them. Their analytic properties lead to the intriguing consequence that a large proportion of proper classes are one-lattice classes.</p>","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 1","pages":"290-311"},"PeriodicalIF":0.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"First moments of \u0000 \u0000 \u0000 GL\u0000 (\u0000 3\u0000 )\u0000 ×\u0000 GL\u0000 (\u0000 2\u0000 )\u0000 \u0000 ${{mathrm{GL}}}(3)times {{mathrm{GL}}}(2)$\u0000 and \u0000 \u0000 \u0000 GL\u0000 (\u0000 2\u0000 )\u0000 \u0000 $ {{mathrm{GL}}}(2)$\u0000 \u0000 \u0000 L\u0000 $L$\u0000 -functions and their applications","authors":"Fei Hou","doi":"10.1002/mana.70099","DOIUrl":"https://doi.org/10.1002/mana.70099","url":null,"abstract":"<p>Let <span></span><math>\u0000 <semantics>\u0000 <mi>F</mi>\u0000 <annotation>$F$</annotation>\u0000 </semantics></math> be a self-dual Hecke–Maaß form for <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>GL</mi>\u0000 <mo>(</mo>\u0000 <mn>3</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>${mathrm{GL}}(3)$</annotation>\u0000 </semantics></math> underlying the symmetric square lift of a <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>GL</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>${mathrm{GL}}(2)$</annotation>\u0000 </semantics></math>-newform of square-free level and trivial nebentypus. In this paper, we are interested in the first moments of the central values of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>GL</mi>\u0000 <mo>(</mo>\u0000 <mn>3</mn>\u0000 <mo>)</mo>\u0000 <mo>×</mo>\u0000 <mi>GL</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$rm GL(3)times GL(2)$</annotation>\u0000 </semantics></math> <span></span><math>\u0000 <semantics>\u0000 <mi>L</mi>\u0000 <annotation>$L$</annotation>\u0000 </semantics></math>-functions and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>GL</mi>\u0000 <mo>(</mo>\u0000 <mn>2</mn>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$rm GL(2)$</annotation>\u0000 </semantics></math> <span></span><math>\u0000 <semantics>\u0000 <mi>L</mi>\u0000 <annotation>$L$</annotation>\u0000 </semantics></math>-functions. As a result, we obtain an estimate for the first moment for <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 <mo>(</mo>\u0000 <mn>1</mn>\u0000 <mo>/</mo>\u0000 <mn>2</mn>\u0000 <mo>,</mo>\u0000 <mi>F</mi>\u0000 <mo>⊗</mo>\u0000 <mi>f</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$L(1/2, Fotimes f)$</annotation>\u0000 </semantics></math> in a family, where <span></span><math>\u0000 <semantics>\u0000 <mi>F</mi>\u0000 <annotation>$F$</annotation>\u0000 </semantics></math> is of the level <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>q</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <annotation>$q^2$</annotation>\u0000 </semantics></math>, and <span></span><math>\u0000 <semantics>\u0000 ","PeriodicalId":49853,"journal":{"name":"Mathematische Nachrichten","volume":"299 2","pages":"316-342"},"PeriodicalIF":0.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146140188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}