{"title":"In Search of Comrade Agronomof: Some Tribonacci History","authors":"H. Tuenter","doi":"10.1080/00029890.2023.2231796","DOIUrl":"https://doi.org/10.1080/00029890.2023.2231796","url":null,"abstract":"Abstract A note from May 1914 by a certain Agronomof in the Belgian journal Mathesis is frequently cited in the context of the mathematical history of the Tribonacci number sequence. We round out the historical perspective by providing details on Agronomof’s life and work, and highlight two late-nineteenth-century occurrences of this number sequence. One occurrence is connected to Charles Darwin’s On the Origin of Species. Furthermore, we show that the main identity in Agronomof’s note can be leveraged to derive several nontrivial identities with surprising ease and elegance. Some of these identities have only recently been proven by different and more laborious methods; others are new.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"708 - 719"},"PeriodicalIF":0.5,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41579303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Combinatorial Proof of a Symmetric Group Character Involution","authors":"P. Renteln","doi":"10.1080/00029890.2023.2242042","DOIUrl":"https://doi.org/10.1080/00029890.2023.2242042","url":null,"abstract":"We give a short combinatorial proof based on the Murnaghan-Nakayama rule of the symmetric group character identity χ λ χ (1 n ) = χ λ (cid:48) , where λ (cid:48) is the conjugate of the partition λ .","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48149307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Determinant Mod p of a Circulant Matrix of Order pm","authors":"Tom Moshaiov","doi":"10.1080/00029890.2023.2240266","DOIUrl":"https://doi.org/10.1080/00029890.2023.2240266","url":null,"abstract":"","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47027254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Tale of Two by Two Matrices","authors":"D. Kalman, R. Mena","doi":"10.1080/00029890.2023.2242039","DOIUrl":"https://doi.org/10.1080/00029890.2023.2242039","url":null,"abstract":"Abstract We formulate the Euclidean algorithm using directed graphs on integer points in the plane and operations on a particular semigroup of two by two matrices. The properties of the graphs and the semigroup provide surprisingly effective tools for solving certain classical diophantine equations, among other applications.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46035694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gagliardo-Nirenberg-Sobolev Inequality: An Induction Proof","authors":"Shibo Liu","doi":"10.1080/00029890.2023.2240683","DOIUrl":"https://doi.org/10.1080/00029890.2023.2240683","url":null,"abstract":"Abstract This paper presents an induction proof of the G-N-S inequality when p = 1, which the author believes is much simpler and more transparent than other proofs found in the literature.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44822927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vesta Coufal, Suzanne Dorée, T. Dray, Frank Farris, Amy Shell-Gellasch, Derek Smith
{"title":"Yueh-Gin Gung and Dr. Charles Y. Hu Award for 2023 to Victor J. Katz for Distinguished Service to Mathematics","authors":"Vesta Coufal, Suzanne Dorée, T. Dray, Frank Farris, Amy Shell-Gellasch, Derek Smith","doi":"10.1080/00029890.2023.2190724","DOIUrl":"https://doi.org/10.1080/00029890.2023.2190724","url":null,"abstract":"The Yueh-Gin Gung and Dr. Charles Y. Hu Award for Distinguished Service to Mathematics is the most prestigious award for service offered by the Mathematical Association of America. It celebrates contributions to the community that have influenced the field of mathematics in a significant and positive way. Victor Katz","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"603 - 605"},"PeriodicalIF":0.5,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45314360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Billiard Circuits in Quadrilaterals","authors":"K. Knox","doi":"10.1080/00029890.2023.2230860","DOIUrl":"https://doi.org/10.1080/00029890.2023.2230860","url":null,"abstract":"Abstract A quadrilateral contains a closed billiard circuit that bounces consecutively on the interiors of its sides each exactly once per cycle, if and only if it is cyclic and its interior contains the center of its circumscribed circle.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"755 - 759"},"PeriodicalIF":0.5,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49140242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sum of a Geometric Series Via the Integral","authors":"B. Chakraborty","doi":"10.1080/00029890.2023.2231164","DOIUrl":"https://doi.org/10.1080/00029890.2023.2231164","url":null,"abstract":"","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"764 - 764"},"PeriodicalIF":0.5,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48060015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Arithmetic Proof of a Theorem of Chan, Long, and Yang","authors":"K. Williams","doi":"10.1080/00029890.2023.2230836","DOIUrl":"https://doi.org/10.1080/00029890.2023.2230836","url":null,"abstract":"Abstract We present a short arithmetic proof of the theorem of Chan, Long, and Yang proved in the Monthly in 2011, which gives explicit formulas for integers x and y such that , where p is a prime satisfying .","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"760 - 763"},"PeriodicalIF":0.5,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46694907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reviews","authors":"Brian Hopkins","doi":"10.1080/00029890.2023.2231826","DOIUrl":"https://doi.org/10.1080/00029890.2023.2231826","url":null,"abstract":"The most revelatory experience of my undergraduate mathematics degree was a writing course offered by James Vick. Well on his way to becoming a vice president in the University of Texas administration, Vick still managed to teach the occasional class. This one, “Proofs, Conjectures, and Controversies,” showed us that mathematics was not always as absolute as implied in our other courses. In particular, there is not always consensus about what constitutes a valid proof and what tools are allowed. One example of controversy was the 1976 computer-assisted proof of the four color theorem, establishing that the countries of every map can be colored with at most four colors so that no two neighboring countries are colored the same. The class readings included the recent Dover edition of Saaty and Kainan’s book [18] on the “assaults and conquest” of that graph theory problem and Leonard Gillman’s celebrated guide to mathematical writing [5]. What an honor to learn about recent and contentious research developments while developing skills in mathematical exposition. The year 1976 was an important year for both the United States and graph theory. In that year of the American bicentennial, Kenneth Appel and Wolfgang Haken of the University of Illinois solved Francis Guthrie’s 1852 four color conjecture. This was one of the rare mathematical results to be mentioned (eventually) in The New York Times [19, p. 209]. Another milestone for graph theory that year was the publication of the first book on its history, Graph Theory 1736–1936 by Norman Biggs, Keith Lloyd, and Robin Wilson [2]. That book opened a sort of trilogy on the history of graph theory, all involving the talented and prolific expositor Robin Wilson. The second book was a 2002 solo effort Four Colors Suffice [19]. The third book, based on the 2012 dissertation of David Parks [16] and also featuring John Watkins, focuses on the period 1876–1976 with an emphasis on US and Canadian contributions to the field. This review will focus on the 2023 book while also discussing it in relation to its two predecessors.","PeriodicalId":7761,"journal":{"name":"American Mathematical Monthly","volume":"130 1","pages":"779 - 784"},"PeriodicalIF":0.5,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44201560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}