{"title":"Absolute convergence of Mellin transforms","authors":"Othman Tyr","doi":"10.1007/s11139-024-00943-1","DOIUrl":"https://doi.org/10.1007/s11139-024-00943-1","url":null,"abstract":"<p>The problem of the integrability of Mellin transforms is presented. Sufficient Lipschitz conditions are given to solve this problem. These results are inspired by well-known works of Titchmarsh in classical Fourier harmonic analysis. Some results on the integrability of Mellin transforms of the Mellin convolutions are also given.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An analogue of Kida’s formula for elliptic curves with additive reduction","authors":"Anwesh Ray, Pratiksha Shingavekar","doi":"10.1007/s11139-024-00920-8","DOIUrl":"https://doi.org/10.1007/s11139-024-00920-8","url":null,"abstract":"<p>We study the Iwasawa theory of <i>p</i>-primary Selmer groups of elliptic curves <i>E</i> over a number field <i>K</i>. Assume that <i>E</i> has additive reduction at the primes of <i>K</i> above <i>p</i>. In this context, we prove that the Iwasawa invariants satisfy an analogue of the Riemann–Hurwitz formula. This generalizes a result of Hachimori and Matsuno. We apply our results to study rank stability questions for elliptic curves in prime cyclic extensions of <span>(mathbb {Q})</span>. These extensions are ordered by their absolute discriminant and we prove an asymptotic lower bound for the density of extensions in which the Iwasawa invariants as well as the rank of the elliptic curve is stable.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Irrationality exponents of certain alternating series","authors":"Iekata Shiokawa","doi":"10.1007/s11139-024-00923-5","DOIUrl":"https://doi.org/10.1007/s11139-024-00923-5","url":null,"abstract":"<p>Let <i>m</i> be a positive integer, <span>((w_n))</span> be a sequence of positive integers, and <span>((y_n))</span> be a sequence of nonzero integers with <span>(y_1ge 1)</span>. Define <span>(q_0=1, q_1=w_0, q_{n+1}=q_{n-1}(w_nq_n^m+y_n) ,,(nge 1))</span>. Under certain assumptions on <span>((w_n))</span> and <span>((y_n))</span>, we give the exact value of the irrationality exponent of the number </p><span>$$begin{aligned} xi =sum _{n=1}^{infty }(-1)^{n-1}frac{y_1y_2cdots y_n}{q_nq_{n-1}}. end{aligned}$$</span>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unimodality of regular partition polynomials","authors":"Xin-Chun Zhan, Bao-Xuan Zhu","doi":"10.1007/s11139-024-00925-3","DOIUrl":"https://doi.org/10.1007/s11139-024-00925-3","url":null,"abstract":"<p>Let <i>n</i>, <i>p</i> and <i>j</i> be integers. Define </p><span>$$begin{aligned} R_{n,p,j}(q):=prod _{k=0}^{n}(1+q^{pk+1})(1+q^{pk+2})cdots (1+q^{pk+j}). end{aligned}$$</span><p>The coefficients of the polynomial <span>(R_{n,p,j}(q))</span> count certain regular partition. Recently, Dong and Ji studied unimodality of the polynomials <span>(R_{n,p,p-1}(q))</span>. As an extension, in this paper, we give a criterion for unimodality of the polynomials <span>( R_{n,p,j}(q))</span> for <span>(p ge 6)</span> and <span>(lceil frac{p+1}{2}rceil le jle p-1.)</span> In particular, using our criterion and Mathematica, we obtain that <span>(R_{n,p,j}(q))</span> is unimodal for <span>(nge 3)</span> if <span>(6le p le 15)</span> and <span>(lceil frac{p+1}{2}rceil le jle p-1.)</span></p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New congruences on partition diamonds with $$n+1$$ copies of n","authors":"Yongqiang Chen, Eric H. Liu, Olivia X. M. Yao","doi":"10.1007/s11139-024-00934-2","DOIUrl":"https://doi.org/10.1007/s11139-024-00934-2","url":null,"abstract":"<p>Recently, Andrews and Paule introduced a partition function <i>PDN</i>1(<i>N</i>) which counts the number of partition diamonds with <span>(n+1)</span> copies of <i>n</i> where summing the parts at the links gives <i>N</i>. They also established the generating function of <i>PDN</i>1(<i>n</i>) and proved congruences modulo 5,7,25,49 for <i>PDN</i>1(<i>n</i>). At the end of their paper, Andrews and Paule asked for the existence of other types of congruence relations for <i>PDN</i>1(<i>n</i>). Motivated by their work, we prove some new congruences modulo 125 and 625 for <i>PDN</i>1(<i>n</i>) by using some identities due to Chern and Tang. In particular, we discover a family of strange congruences modulo 625 for <i>PDN</i>1(<i>n</i>). For example, we prove that for <span>(kge 0)</span>, </p><span>$$begin{aligned} PDN1left( 5^7 cdot 7^{8k}+frac{ 19cdot 5^7cdot 7^{8k}+1 }{24} right) equiv 5^3 pmod {5^4}. end{aligned}$$</span>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"155 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On p-divisibility of Fourier coefficients of Hermitian modular forms","authors":"Shoyu Nagaoka","doi":"10.1007/s11139-024-00924-4","DOIUrl":"https://doi.org/10.1007/s11139-024-00924-4","url":null,"abstract":"<p>We describe the <i>p</i>-divisibility transposition for the Fourier coefficients of Hermitian modular forms. The results show that the same phenomenon as that for Siegel modular forms holds for Hermitian modular forms</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Su-Ping Cui, Hai-Xing Du, Nancy S. S. Gu, Liuquan Wang
{"title":"Hecke-type double sums and the Bailey transform","authors":"Su-Ping Cui, Hai-Xing Du, Nancy S. S. Gu, Liuquan Wang","doi":"10.1007/s11139-024-00926-2","DOIUrl":"https://doi.org/10.1007/s11139-024-00926-2","url":null,"abstract":"<p>Hecke-type double sums play a crucial role in proving many identities related to mock theta functions given by Ramanujan. In the literature, the Bailey pair machinery is an efficient tool to derive Hecke-type double sums for mock theta functions. In this paper, by using some Bailey pairs and conjugate Bailey pairs, and then applying the Bailey transform, we establish some trivariate identities which imply the Hecke-type double sums for some classical mock theta functions of orders 3, 6, and 10. Meanwhile, we generalize a bivariate Hecke-type identity due to Garvan.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A further look at the overpartition function modulo $$2^4$$ and $$2^5$$","authors":"Ranganatha Dasappa, Gedela Kavya Keerthana","doi":"10.1007/s11139-024-00933-3","DOIUrl":"https://doi.org/10.1007/s11139-024-00933-3","url":null,"abstract":"<p>In this paper, we describe a systematic way of obtaining the exact generating functions for <span>(overline{p}(2n))</span>, <span>(overline{p}(4n))</span> (first proved by Fortin et al.), <span>(overline{p}(8n))</span>, <span>(overline{p}(16n))</span>, etc. where <span>(overline{p}(n))</span> denotes the number of overpartitions of <i>n</i>. We further establish several new infinite families of congruences modulo <span>(2^4)</span> and <span>(2^5)</span> for <span>(overline{p}(n))</span>. For example, we prove that for all <span>(n, alpha , beta ge 0)</span> and primes <span>(pge 5)</span>, </p><span>$$begin{aligned} overline{p}left( 3^{4alpha +1}p^{2beta +1}left( 24pn+24j+7pright) right)&equiv 0pmod {2^5} end{aligned}$$</span><p>and </p><span>$$begin{aligned} overline{p}left( 3^{2alpha +1}(24n+23)right)&equiv 0pmod {2^5}, end{aligned}$$</span><p>where <span>(bigl (frac{-6}{p}bigr )=-1)</span> and <span>(1le jle p-1)</span>. The last congruence was proved by Xiong (Int J Number Theory 12:1195–1208, 2016) for modulo <span>(2^4)</span>.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Palindrome partitions and the Calkin–Wilf tree","authors":"David J. Hemmer, Karlee J. Westrem","doi":"10.1007/s11139-024-00927-1","DOIUrl":"https://doi.org/10.1007/s11139-024-00927-1","url":null,"abstract":"<p>There is a well-known bijection between finite binary sequences and integer partitions. Sequences of length <i>r</i> correspond to partitions of perimeter <span>(r+1)</span>. Motivated by work on rational numbers in the Calkin–Wilf tree, we classify partitions whose corresponding binary sequence is a palindrome. We give a generating function that counts these partitions, and describe how to efficiently generate all of them. Atypically for partition generating functions, we find an unusual significance to prime degrees. Specifically, we prove there are nontrivial <i>palindrome partitions</i> of <i>n</i> except when <span>(n=3)</span> or <span>(n+1)</span> is prime. We find an interesting new “branching diagram” for partitions, similar to Young’s lattice, with an action of the Klein four group corresponding to natural operations on the binary sequences.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An unsolved question surrounding the Generalized Laguerre Polynomial $$L_{n}^{(n)}(x)$$","authors":"Pradipto Banerjee","doi":"10.1007/s11139-024-00932-4","DOIUrl":"https://doi.org/10.1007/s11139-024-00932-4","url":null,"abstract":"<p>We examine the family of generalized Laguerre polynomials <span>(L_{n}^{(n)}(x))</span>. In 1989, Gow discovered that if <i>n</i> is even, then the discriminant of <span>(L_{n}^{(n)}(x))</span> is a nonzero square of a rational number. Additionally, in the case where the polynomial <span>(L_{n}^{(n)}(x))</span> is irreducible over the rationals, the associated Galois group is the alternating group <span>(A_{n})</span>. Filaseta et al. (2012) established the irreducibility of <span>(L_{n}^{(n)}(x))</span> for every <span>(n>2)</span> satisfying <span>(2pmod {4})</span>. They also demonstrated that if <i>n</i> is <span>(0pmod {4})</span>, then <span>(L_{n}^{(n)}(x))</span> has a linear factor if it is not irreducible. The question of whether <span>(L_{n}^{(n)}(x))</span> has a linear factor when <i>n</i> is <span>(0pmod {4})</span> remained unanswered. We resolve this question by proving that <span>(L_{n}^{(n)}(x))</span> does not have a linear factor for sufficiently large <i>n</i>. This conclusion completes the classification of generalized Laguerre polynomials having Galois group the alternating group, excluding a finite set of exceptions.</p>","PeriodicalId":501430,"journal":{"name":"The Ramanujan Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}