{"title":"An affine isoperimetric inequality for log-concave functions","authors":"Zengle Zhang , Jiazu Zhou","doi":"10.1016/j.aam.2025.102956","DOIUrl":"10.1016/j.aam.2025.102956","url":null,"abstract":"<div><div>The authors gave an affine isoperimetric inequality <span><span>[41]</span></span> that gives a lower bound for the volume of a polar body and the equality holds if and only if the body is a simplex. In this paper, we give a functional isoperimetric inequality for log-concave functions that contains the affine isoperimetric inequality of Lutwak, Yang and Zhang in <span><span>[41]</span></span>.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102956"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144911887","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":"q-Binomial identities finder","authors":"Hao Zhong, Leqi Zhao","doi":"10.1016/j.aam.2025.102965","DOIUrl":"10.1016/j.aam.2025.102965","url":null,"abstract":"<div><div>This paper presents a symbolic computation method for automatically transforming <em>q</em>-hypergeometric identities to <em>q</em>-binomial identities. Through this method, many previously proven <em>q</em>-binomial identities, including <em>q</em>-Saalschütz's formula and <em>q</em>-Suranyi's formula, are re-fund, and numerous new ones are discovered. Moreover, the generation of the identities is accompanied by the corresponding proofs. During the transformation process, different ranges of variable values and various combinations of <em>q</em>-Pochhammer symbols yield different identities. The algorithm maps variable constraints to positive elements in an ordered vector space and employs a backtracking method to provide the feasible variable constraints and <em>q</em>-binomial coefficient combinations for each step.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102965"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026317","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":"Representation theory and central limit theorems for traces of commutators for compact Lie groups","authors":"Jason Fulman","doi":"10.1016/j.aam.2025.102962","DOIUrl":"10.1016/j.aam.2025.102962","url":null,"abstract":"<div><div>There has been some work in the literature on limit theorems for the trace of commutators for compact Lie groups. We revisit this from the perspective of combinatorial representation theory.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102962"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889329","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}
Christopher Reichling, Leo van Iersel, Yukihiro Murakami
{"title":"Metrics for classes of semi-binary phylogenetic networks using μ-representations","authors":"Christopher Reichling, Leo van Iersel, Yukihiro Murakami","doi":"10.1016/j.aam.2025.102953","DOIUrl":"10.1016/j.aam.2025.102953","url":null,"abstract":"<div><div>Phylogenetic networks are useful in representing the evolutionary history of taxa. In certain scenarios, one requires a way to compare different networks. In practice, this can be rather difficult, except within specific classes of networks. In this paper, we derive metrics for the class of <em>orchard networks</em> and the class of <em>strongly reticulation-visible</em> networks, from variants of so-called <em>μ-representations</em>, which are vector representations of networks. For both network classes, we impose degree constraints on the vertices, by considering <em>semi-binary</em> networks.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102953"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878156","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":"Counting the number of group orbits by marrying the Burnside process with importance sampling","authors":"Persi Diaconis , Chenyang Zhong","doi":"10.1016/j.aam.2025.102955","DOIUrl":"10.1016/j.aam.2025.102955","url":null,"abstract":"<div><div>This paper introduces a novel and general algorithm for approximately counting the number of orbits under group actions. The method is based on combining the Burnside process and importance sampling. Specializing to unitriangular groups yields an efficient algorithm for estimating the number of conjugacy classes of such groups.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102955"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886384","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 fractal patterns in Ulam words","authors":"Andrei Mandelshtam","doi":"10.1016/j.aam.2025.102954","DOIUrl":"10.1016/j.aam.2025.102954","url":null,"abstract":"<div><div>Ulam words are binary words defined recursively as follows: the length-1 Ulam words are 0 and 1, and a binary word of length <em>n</em> is Ulam if and only if it is expressible uniquely as a concatenation of two shorter, distinct Ulam words. We discover, fully describe, and prove a surprisingly rich structure already in the set of Ulam words containing exactly two 1's. In particular, this leads to a complete description of such words and a logarithmic-time algorithm to determine whether a binary word with two 1's is Ulam. Along the way, we uncover delicate parity and biperiodicity properties, as well as sharp bounds on the number of 0's outside the two 1's. We also show that sets of Ulam words indexed by the number <em>y</em> of 0's between the two 1's have intricate tensor-based hierarchical structures determined by the arithmetic properties of <em>y</em>. This allows us to construct an infinite family of self-similar Ulam-word-based fractals indexed by the set of 2-adic integers, containing the outward Sierpinski gasket as a special case.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102954"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010477","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":"SL(n) covariant matrix-valued valuations on Orlicz spaces","authors":"Chunna Zeng , Yu Lan","doi":"10.1016/j.aam.2025.102960","DOIUrl":"10.1016/j.aam.2025.102960","url":null,"abstract":"<div><div>All continuous, <span><math><mrow><mi>SL</mi></mrow><mo>(</mo><mi>n</mi><mo>)</mo></math></span> covariant valuations on Orlicz spaces are completely classified without any symmetric assumptions. It is shown that the moment matrix is the only such valuation if <span><math><mi>n</mi><mo>≥</mo><mn>3</mn></math></span>, while a new functional shows up in dimension two.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102960"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886379","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 records and zeros of a deterministic random walk","authors":"Henk Bruin, Robbert Fokkink","doi":"10.1016/j.aam.2025.102963","DOIUrl":"10.1016/j.aam.2025.102963","url":null,"abstract":"<div><div>We settle two questions on sequence A120243 in the OEIS that were raised by Clark Kimberling and partly solve a conjecture of Van de Lune and Arias de Reyna. We extend Kimberling's questions to the framework of deterministic random walks, automatic sequences, and linear recurrences. Our results indicate that there may be a deeper connection between these structures. In particular, we conjecture that the records of deterministic random walks are <em>ξ</em>-Ostrowski automatic for quadratic rotation numbers <em>ξ</em>.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102963"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019453","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}
Eva Czabarka , Steven Kelk , Vincent Moulton , László A. Székely
{"title":"Coconvex characters on collections of phylogenetic trees","authors":"Eva Czabarka , Steven Kelk , Vincent Moulton , László A. Székely","doi":"10.1016/j.aam.2025.102952","DOIUrl":"10.1016/j.aam.2025.102952","url":null,"abstract":"<div><div>In phylogenetics, a key problem is to construct evolutionary trees from collections of characters where, for a set <em>X</em> of species, a character is simply a function from <em>X</em> onto a set of states. In this context, a key concept is convexity, where a character is convex on a tree with leaf set <em>X</em> if the collection of subtrees spanned by the leaves of the tree that have the same state are pairwise disjoint. Although collections of convex characters on a single tree have been extensively studied over the past few decades, very little is known about <em>coconvex characters</em>, that is, characters that are simultaneously convex on a collection of trees. As a starting point to better understand coconvexity, in this paper we prove a number of extremal results for the following question: <em>What is the minimal number of coconvex characters on a collection of n-leaved trees taken over all collections of size</em> <span><math><mi>t</mi><mo>≥</mo><mn>2</mn></math></span><em>, also if we restrict to coconvex characters which map to k states?</em> As an application of coconvexity, we introduce a new one-parameter family of tree metrics, which range between the coarse Robinson-Foulds distance and the much finer quartet distance. We show that bounds on the quantities in the above question translate into bounds for the diameter of the tree space for the new distances. Our results open up several new interesting directions and questions which have potential applications to, for example, tree spaces and phylogenomics.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102952"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865208","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":"q-supercongruences for truncated q-Appell series","authors":"Haihong He , Xiaoxia Wang","doi":"10.1016/j.aam.2025.102961","DOIUrl":"10.1016/j.aam.2025.102961","url":null,"abstract":"<div><div>Congruences and <em>q</em>-congruences for the truncated Appell series are quite finite in the literature. In this paper, we introduce the truncated <em>q</em>-Appell series and investigate their congruence properties. Specifically, using two hypergeometric summations, the ‘creative microscoping’ method formulated by Guo and Zudilin and the Chinese remainder theorem for coprime polynomials, we establish some <em>q</em>-supercongruences on the truncated <em>q</em>-Appell series <span><math><msup><mrow><mi>Φ</mi></mrow><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup><mo>,</mo><msup><mrow><mi>Φ</mi></mrow><mrow><mo>(</mo><mn>2</mn><mo>)</mo></mrow></msup><mo>,</mo><msup><mrow><mi>Φ</mi></mrow><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></msup></math></span>. Moreover, in terms of the <em>q</em>-Zeilberger algorithm, a <em>q</em>-supercongruence for the truncated <em>q</em>-Appell series <span><math><msup><mrow><mi>Φ</mi></mrow><mrow><mo>(</mo><mn>4</mn><mo>)</mo></mrow></msup></math></span> is built, which is a new <em>q</em>-analogue of a conjecture of Apagodu and Zeilberger. As conclusions, we immediately obtain some congruences of the truncated Appell series.</div></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":"172 ","pages":"Article 102961"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886385","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}