{"title":"Compact groups with a set of positive Haar measure satisfying a nilpotent law","authors":"A. Abdollahi, Meisam Soleimani Malekan","doi":"10.1017/S0305004121000542","DOIUrl":"https://doi.org/10.1017/S0305004121000542","url":null,"abstract":"Abstract The following question is proposed by Martino, Tointon, Valiunas and Ventura in [4, question 1·20]: Let G be a compact group, and suppose that \u0000[mathcal{N}_k(G) = {(x_1,dots,x_{k+1}) in G^{k+1} ;|; [x_1,dots, x_{k+1}] = 1}]\u0000 has positive Haar measure in \u0000$G^{k+1}$\u0000 . Does G have an open k-step nilpotent subgroup? We give a positive answer for \u0000$k = 2$\u0000 .","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"4 1","pages":"329 - 332"},"PeriodicalIF":0.8,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74612612","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":"Number fields without universal quadratic forms of small rank exist in most degrees","authors":"Vítězslav Kala","doi":"10.1017/S0305004122000214","DOIUrl":"https://doi.org/10.1017/S0305004122000214","url":null,"abstract":"Abstract We prove that in each degree divisible by 2 or 3, there are infinitely many totally real number fields that require universal quadratic forms to have arbitrarily large rank.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"16 1","pages":"225 - 231"},"PeriodicalIF":0.8,"publicationDate":"2021-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76019405","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":"Simultaneous p-adic Diophantine approximation","authors":"V. Beresnevich, J. Levesley, Benjamin C. Ward","doi":"10.1017/S0305004122000470","DOIUrl":"https://doi.org/10.1017/S0305004122000470","url":null,"abstract":"Abstract The aim of this paper is to develop the theory of weighted Diophantine approximation of rational numbers to p-adic numbers. Firstly, we establish complete analogues of Khintchine’s theorem, the Duffin–Schaeffer theorem and the Jarník–Besicovitch theorem for ‘weighted’ simultaneous Diophantine approximation in the p-adic case. Secondly, we obtain a lower bound for the Hausdorff dimension of weighted simultaneously approximable points lying on p-adic manifolds. This is valid for very general classes of curves and manifolds and have natural constraints on the exponents of approximation. The key tools we use in our proofs are the Mass Transference Principle, including its recent extension due to Wang and Wu in 2019, and a Zero-One law for weighted p-adic approximations established in this paper.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"8 1","pages":"13 - 50"},"PeriodicalIF":0.8,"publicationDate":"2021-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75032939","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":"PSP volume 170 issue 1 Cover and Back matter","authors":"","doi":"10.1017/s0305004121000062","DOIUrl":"https://doi.org/10.1017/s0305004121000062","url":null,"abstract":"","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"12 1","pages":"b1 - b2"},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73178729","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":"PSP volume 170 issue 1 Cover and Front matter","authors":"","doi":"10.1017/s0305004121000050","DOIUrl":"https://doi.org/10.1017/s0305004121000050","url":null,"abstract":"","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"222 1","pages":"f1 - f2"},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76986597","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":"Divisors computing minimal log discrepancies on lc surfaces","authors":"Jihao Liu, Lingyao Xie","doi":"10.1017/S0305004123000051","DOIUrl":"https://doi.org/10.1017/S0305004123000051","url":null,"abstract":"Abstract Let \u0000$(Xni x,B)$\u0000 be an lc surface germ. If \u0000$Xni x$\u0000 is klt, we show that there exists a divisor computing the minimal log discrepancy of \u0000$(Xni x,B)$\u0000 that is a Kollár component of \u0000$Xni x$\u0000 . If \u0000$Bnot=0$\u0000 or \u0000$Xni x$\u0000 is not Du Val, we show that any divisor computing the minimal log discrepancy of \u0000$(Xni x,B)$\u0000 is a potential lc place of \u0000$Xni x$\u0000 . This extends a result of Blum and Kawakita who independently showed that any divisor computing the minimal log discrepancy on a smooth surface is a potential lc place.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"27 1","pages":"107 - 128"},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82514515","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":"The Log Product Formula in Quantum K-theory","authors":"You-Cheng Chou, Leo Herr, Yuan-Pin Lee","doi":"10.1017/S0305004123000063","DOIUrl":"https://doi.org/10.1017/S0305004123000063","url":null,"abstract":"Abstract We prove a formula expressing the K-theoretic log Gromov-Witten invariants of a product of log smooth varieties \u0000$V times W$\u0000 in terms of the invariants of V and W. The proof requires introducing log virtual fundamental classes in K-theory and verifying their various functorial properties. We introduce a log version of K-theory and prove the formula there as well.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"34 1","pages":"225 - 252"},"PeriodicalIF":0.8,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80045615","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":"Uniform bounds for norms of theta series and arithmetic applications","authors":"F. Waibel","doi":"10.1017/S0305004122000081","DOIUrl":"https://doi.org/10.1017/S0305004122000081","url":null,"abstract":"Abstract We prove uniform bounds for the Petersson norm of the cuspidal part of the theta series. This gives an improved asymptotic formula for the number of representations by a quadratic form. As an application, we show that every integer \u0000$n neq 0,4,7 ,(textrm{mod} 8)$\u0000 is represented as \u0000$n= x_1^2 + x_2^2 + x_3^3$\u0000 for integers \u0000$x_1,x_2,x_3$\u0000 such that the product \u0000$x_1x_2x_3$\u0000 has at most 72 prime divisors.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"32 1","pages":"669 - 691"},"PeriodicalIF":0.8,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80755708","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":"Corrigendum: towards an understanding of ramified extensions of structured ring spectra","authors":"B. Dundas, A. Lindenstrauss, Birgit Richter","doi":"10.1017/S0305004120000274","DOIUrl":"https://doi.org/10.1017/S0305004120000274","url":null,"abstract":"","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"418 1","pages":"247 - 248"},"PeriodicalIF":0.8,"publicationDate":"2020-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76626941","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":"Fourier duality in the Brascamp–Lieb inequality","authors":"Jonathan Bennett, Eunhee Jeong","doi":"10.1017/S0305004121000608","DOIUrl":"https://doi.org/10.1017/S0305004121000608","url":null,"abstract":"Abstract It was observed recently in work of Bez, Buschenhenke, Cowling, Flock and the first author, that the euclidean Brascamp–Lieb inequality satisfies a natural and useful Fourier duality property. The purpose of this paper is to establish an appropriate discrete analogue of this. Our main result identifies the Brascamp–Lieb constants on (finitely-generated) discrete abelian groups with Brascamp–Lieb constants on their (Pontryagin) duals. As will become apparent, the natural setting for this duality principle is that of locally compact abelian groups, and this raises basic questions about Brascamp–Lieb constants formulated in this generality.","PeriodicalId":18320,"journal":{"name":"Mathematical Proceedings of the Cambridge Philosophical Society","volume":"32 1","pages":"387 - 409"},"PeriodicalIF":0.8,"publicationDate":"2020-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77667587","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}