{"title":"Bilateral Lerch theta and theta star function and Quadrilateral Lerch zeta and zeta star functions","authors":"T. Nakamura","doi":"10.1007/s10476-026-00153-5","DOIUrl":"10.1007/s10476-026-00153-5","url":null,"abstract":"<div><p>In the present paper, we construct theta functions with two parameters <span>(a, b in mathbb{R})</span> that satisfy Jacobi's modular relation. \u0000Furthermore, we define zeta functions, also depending on two real parameters <span>(a, b in mathbb{R})</span> and which are derived from these theta functions, which satisfy Riemann's functional equation. To the best of our knowledge, these zeta functions are the first known examples that simultaneously satisfy Riemann's functional equation and involve two independent parameters.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"255 - 276"},"PeriodicalIF":0.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10476-026-00153-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The weak type (1, 1) bounds for the (rho)-variation operator associated with the Poisson semigroup","authors":"J. Wang, H. Li, H. Liu","doi":"10.1007/s10476-026-00149-1","DOIUrl":"10.1007/s10476-026-00149-1","url":null,"abstract":"<div><p>We prove that the best constant in the weak type (1, 1) inequality for the <span>(rho)</span>-variation operator associated with the Poisson semigroup grows at most like <span>(O(n^{3/2}))</span>. Moreover, we provide a limit result for the weak type (1, 1) bound.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"403 - 420"},"PeriodicalIF":0.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665619","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":"Uniqueness of norm and faithfulness of some product Banach algebras","authors":"H. V. Dedania, J. G. Patel","doi":"10.1007/s10476-026-00143-7","DOIUrl":"10.1007/s10476-026-00143-7","url":null,"abstract":"<div><p>We prove that the faithful and the uniqueness of norm properties are stable in different product algebras, such as direct-sum product algebras,\u0000 convolution product algebras, and the module product algebras. Furthermore, we show that these properties are not stable in null product algebras. \u0000 Also, we provide a common sufficient condition, in terms of the algebra norm, for the co-dimension \u0000 of <span>(mathcal{A}^2 = operatorname {span} { ab : a,b in mathcal{A}})</span>\u0000 to be finite in <span>(mathcal{A})</span>\u0000 and <span>(mathcal{A}^{2} = mathcal{A})</span>\u0000(whenever <span>(mathcal{A}^2)</span>\u0000 being dense in <span>(mathcal{A})</span>\u0000, i.e., <span>(overline{mathcal{A}^2} = mathcal{A}))</span>\u0000.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"45 - 51"},"PeriodicalIF":0.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665675","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":"Kolmogorov widths of anisotropic Sobolev classes","authors":"A. A. Vasil’eva","doi":"10.1007/s10476-026-00148-2","DOIUrl":"10.1007/s10476-026-00148-2","url":null,"abstract":"<div><p>In this article, order estimates for the Kolmogorov widths of periodic anisotropic Sobolev and Nikol'skii classes are obtained, as well as order estimates for the Kolmogorov widths of anisotropic finite-dimensional balls.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"375 - 402"},"PeriodicalIF":0.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665740","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":"On the constant and extremal function for Hardy inequality in (L_p)","authors":"I. Gadjev","doi":"10.1007/s10476-026-00151-7","DOIUrl":"10.1007/s10476-026-00151-7","url":null,"abstract":"<div><p>We study the behavior of the smallest possible constant <span>(d(a,b))</span> in Hardy inequality\u0000</p><div><div><span>$$\u0000int_a^bBig(frac{1}{x}int_a^xf(t) , dt Big)^p,dxleq\u0000d(a,b)int_a^b [f(x)]^p ,dx.\u0000$$</span></div></div><p>The exact rate of convergence of <span>(d(a,b))</span> is established and \u0000the “almost extremal” function is found.\u0000</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"73 - 86"},"PeriodicalIF":0.5,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665722","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":"Homeomorphism theorem for sums of translates on the real axis","authors":"T. M. Nikiforova","doi":"10.1007/s10476-026-00154-4","DOIUrl":"10.1007/s10476-026-00154-4","url":null,"abstract":"<div><p>\u0000In this paper, we study <i>sums of translates</i> on the real axis. These functions generalize logarithms of weighted algebraic polynomials. Namely, we are dealing with functions\u0000</p><div><div><span>$$(Ftext{y},t) := J(t) + sum _{j=1}^n K_j(t-y_j), quad text{y} := (y1,ldots,y_n), y_1 le cdots le y_n, t in mathbb{R},$$</span></div></div><p>\u0000where the <i>kernels</i><span>(K_1,ldots,K_n)</span> are concave on <span>((-infty,0))</span> and on <span>((0,infty))</span>, having a singularity at <span>(0)</span>, and <span>(Jcolon mathbb{R}to mathbb{R}cup{-infty})</span> is\u0000the <i>field function</i>. We consider \"local maxima\"\u0000</p><div><div><span>$$m_0(text{y}) := sup _{t in (-infty, y_1]} F(text{y}, t), quad m_n(text{y}) := sup _{t in [y_n, infty)} F(text{y}, t),$$</span></div></div><div><div><span>$$m_j(text{y}) := sup _{t in [y_j, y_{j+1}]} F(text{y}, t), quad j = 1,ldots,n-1, $$</span></div></div><p>\u0000and the difference function\u0000</p><div><div><span>$$(Dtext{y}) := (m_1text({y})-m_0text({y}), m_2text({y})-m_1text({y}), cdots, m_ntext({y})-m_{n-1}text({y})). $$</span></div></div><p>\u0000We prove that, under certain assumptions on the kernels and the field, <span>(D)</span> is a homeomorphism between its domain and <span>(mathbb{R}^n)</span>. \u0000</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"307 - 331"},"PeriodicalIF":0.5,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665674","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":"On real functions with graphs either connected or locally connected","authors":"G. Kuba","doi":"10.1007/s10476-026-00152-6","DOIUrl":"10.1007/s10476-026-00152-6","url":null,"abstract":"<div><p>Let <span>( mathcal{G} )</span> denote the \u0000family of all subspaces <span>( G )</span> of the plane <span>( mathbb{R}^2)</span>\u0000such that <span>( G )</span> is the graph of a function from <span>( mathbb{R})</span> to <span>( mathbb{R})</span>.\u0000We prove that <span>( mathcal{G} )</span> \u0000has two subfamilies <span>( mathcal{G}_1,mathcal{G}_2 )</span> of <i>connected</i>\u0000spaces such that the cardinality of <span>( mathcal{G}_1 )</span> is <span>( mathbf{c} :=2^{aleph_0} )</span> \u0000and the cardinality of <span>( mathcal{G}_2 )</span> is <span>( 2^ mathbf{c} )</span>, \u0000every space in <span>( mathcal{G}_1 )</span> is <i>completely metrizable</i>,\u0000each <span>( Ginmathcal{G}_2 )</span> is a dense subset of <span>( mathbb{R}^2)</span>,\u0000and if <span>( X_1,X_2 in mathcal{G}_1cupmathcal{G}_2 )</span> are distinct\u0000then the space <span>( X_1 )</span> is neither homeomorphic to a subspace\u0000of <span>( X_2 )</span> nor homeomorphic to a proper subspace of <span>( X_1)</span>.\u0000On the other hand, the family <span>( mathcal{G} )</span> contains precisely \u0000<span>(aleph_0 )</span> <i>locally connected</i> spaces\u0000up to homeomorphism, and if <span>( X)</span>, <span>(Y )</span> are such spaces (including \u0000the case <span>(X=Y)</span>) then <span>(X )</span> is homeomorphic to some proper subspace of <span>( Y)</span>.\u0000Furthermore, if <span>( tau )</span> is a topology on the set <span>( mathbb{R} )</span>\u0000finer than the Euclidean topology and the space <span>( ( mathbb{R},tau) )</span> is separable and locally connected, then the space is locally compact and \u0000homeomorphic to some space in <span>( mathcal{G} )</span>. \u0000In a very natural way we establish a complete classification of all these refinements <span>( tau )</span> of the real line. </p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"153 - 172"},"PeriodicalIF":0.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665676","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":"Zalcman-Pang lemma for holomorphic curves in (mathbb{P}^N(mathbb{C}))","authors":"S. Mehta, K. S. Charak","doi":"10.1007/s10476-026-00145-5","DOIUrl":"10.1007/s10476-026-00145-5","url":null,"abstract":"<div><p>We obtain a Picard-type theorem for holomorphic curves. By introducing a derivative that extends the spherical derivative of meromorphic functions, we obtain an extension of Marty's Theorem and the Zalcman-Pang Lemma to a family of holomorphic curves. Finally, as an application of these results, we obtain a normality criterion for a family of holomorphic curves whose derived curves satisfy certain conditions.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"209 - 231"},"PeriodicalIF":0.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665617","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":"On the average scale-invariant Cassinian metric","authors":"M. Mohapatra, A. Rasila, M. Vuorinen","doi":"10.1007/s10476-026-00146-4","DOIUrl":"10.1007/s10476-026-00146-4","url":null,"abstract":"<div><p>We establish geometric relationships between the average scale-invariant Cassinian metric and other hyperbolic type metrics. We study the local convexity properties of the scale-invariant metric balls in Euclidean once punctured spaces. In addition, we study Lipschitz-conditions with respect to these metrics.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"233 - 253"},"PeriodicalIF":0.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665700","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":"Turán type inequalities for modified big (q)\u0000-Bessel functions","authors":"E. Deniz, S. Korkmaz, Y. özkan","doi":"10.1007/s10476-026-00150-8","DOIUrl":"10.1007/s10476-026-00150-8","url":null,"abstract":"<div><p>Our aim in this paper is to derive some Turán type inequalities for modified big <span>(q)</span>\u0000-Bessel functions. \u0000Furthermore, some Turán type inequalities of sections for series of aforementioned functions are established. The method is based on proving monotonicity \u0000for the special ratio of sections for series of such functions.</p></div>","PeriodicalId":55518,"journal":{"name":"Analysis Mathematica","volume":"52 1","pages":"53 - 71"},"PeriodicalIF":0.5,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665720","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}