Bulletin of the Australian Mathematical Society最新文献

{"title":"SECOND HANKEL DETERMINANT FOR LOGARITHMIC INVERSE COEFFICIENTS OF CONVEX AND STARLIKE FUNCTIONS","authors":"VASUDEVARAO ALLU, AMAL SHAJI","doi":"10.1017/s0004972724000200","DOIUrl":"https://doi.org/10.1017/s0004972724000200","url":null,"abstract":"<p>We obtain sharp bounds for the second Hankel determinant of logarithmic inverse coefficients for starlike and convex functions.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140617598","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":"ASYMPTOTIC BEHAVIOUR FOR PRODUCTS OF CONSECUTIVE PARTIAL QUOTIENTS IN CONTINUED FRACTIONS","authors":"XIAO CHEN, LULU FANG, JUNJIE LI, LEI SHANG, XIN ZENG","doi":"10.1017/s000497272400025x","DOIUrl":"https://doi.org/10.1017/s000497272400025x","url":null,"abstract":"<p>Let <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417094313995-0120:S000497272400025X:S000497272400025X_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$[a_1(x),a_2(x),a_3(x),ldots ]$</span></span></img></span></span> be the continued fraction expansion of an irrational number <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417094313995-0120:S000497272400025X:S000497272400025X_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$xin [0,1)$</span></span></img></span></span>. We are concerned with the asymptotic behaviour of the product of consecutive partial quotients of <span>x</span>. We prove that, for Lebesgue almost all <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417094313995-0120:S000497272400025X:S000497272400025X_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$xin [0,1)$</span></span></img></span></span>, <span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417094313995-0120:S000497272400025X:S000497272400025X_eqnu1.png\"><span data-mathjax-type=\"texmath\"><span>$$ begin{align*} liminf_{n to infty} frac{log (a_n(x)a_{n+1}(x))}{log n} = 0quad text{and}quad limsup_{n to infty} frac{log (a_n(x)a_{n+1}(x))}{log n}=1. end{align*} $$</span></span></img></span></p><p>We also study the Baire category and the Hausdorff dimension of the set of points for which the above liminf and limsup have other different values and similarly analyse the weighted product of consecutive partial quotients.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140609164","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":"NEW CONGRUENCES FOR THE TRUNCATED APPELL SERIES","authors":"XIAOXIA WANG, WENJIE YU","doi":"10.1017/s0004972724000236","DOIUrl":"https://doi.org/10.1017/s0004972724000236","url":null,"abstract":"<p>Liu [‘Supercongruences for truncated Appell series’, <span>Colloq. Math.</span> <span>158</span>(2) (2019), 255–263] and Lin and Liu [‘Congruences for the truncated Appell series <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417092342642-0507:S0004972724000236:S0004972724000236_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$F_3$</span></span></img></span></span> and <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417092342642-0507:S0004972724000236:S0004972724000236_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$F_4$</span></span></img></span></span>’, <span>Integral Transforms Spec. Funct.</span> <span>31</span>(1) (2020), 10–17] confirmed four supercongruences for truncated Appell series. Motivated by their work, we give a new supercongruence for the truncated Appell series <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240417092342642-0507:S0004972724000236:S0004972724000236_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$F_{1}$</span></span></img></span></span>, together with two generalisations of this supercongruence, by establishing its <span>q</span>-analogues.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608553","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":"COUPLED FREE FERMION CONFORMAL FIELD THEORY AND REPRESENTATIONS","authors":"Bolin Han","doi":"10.1017/s0004972724000224","DOIUrl":"https://doi.org/10.1017/s0004972724000224","url":null,"abstract":"","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140700205","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":"APPROXIMATION OF IRRATIONAL NUMBERS BY PAIRS OF INTEGERS FROM A LARGE SET","authors":"ARTŪRAS DUBICKAS","doi":"10.1017/s0004972724000194","DOIUrl":"https://doi.org/10.1017/s0004972724000194","url":null,"abstract":"We show that there is a set <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline1.png\" /> <jats:tex-math> $S subseteq {mathbb N}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> with lower density arbitrarily close to <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline2.png\" /> <jats:tex-math> $1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> such that, for each sufficiently large real number <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline3.png\" /> <jats:tex-math> $alpha $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, the inequality <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline4.png\" /> <jats:tex-math> $|malpha -n| geq 1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> holds for every pair <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline5.png\" /> <jats:tex-math> $(m,n) in S^2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. On the other hand, if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline6.png\" /> <jats:tex-math> $S subseteq {mathbb N}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> has density <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline7.png\" /> <jats:tex-math> $1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, then, for each irrational <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline8.png\" /> <jats:tex-math> $alpha&gt;0$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and any positive <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline9.png\" /> <jats:tex-math> $varepsilon $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, there exist <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000194_inline10.png\" /> <jats:tex-math> $m,n in S$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> for which <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140594963","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":"CHARACTERISATION OF PRIMES DIVIDING THE INDEX OF A CLASS OF POLYNOMIALS AND ITS APPLICATIONS","authors":"ANUJ JAKHAR","doi":"10.1017/s0004972724000182","DOIUrl":"https://doi.org/10.1017/s0004972724000182","url":null,"abstract":"<p>Let <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline1.png\"><span data-mathjax-type=\"texmath\"><span>${mathbb {Z}}_{K}$</span></span></img></span></span> denote the ring of algebraic integers of an algebraic number field <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$K = {mathbb Q}(theta )$</span></span></img></span></span>, where <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$theta $</span></span></img></span></span> is a root of a monic irreducible polynomial <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$f(x) = x^n + a(bx+c)^m in {mathbb {Z}}[x]$</span></span></img></span></span>, <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline5.png\"><span data-mathjax-type=\"texmath\"><span>$1leq m&lt;n$</span></span></img></span></span>. We say <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline6.png\"><span data-mathjax-type=\"texmath\"><span>$f(x)$</span></span></img></span></span> is monogenic if <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline7.png\"><span data-mathjax-type=\"texmath\"><span>${1, theta , ldots , theta ^{n-1}}$</span></span></img></span></span> is a basis for <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline8.png\"><span data-mathjax-type=\"texmath\"><span>${mathbb {Z}}_K$</span></span></img></span></span>. We give necessary and sufficient conditions involving only <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240328105942060-0650:S0004972724000182:S0004972724000182_inline9.png\"><span data-mathjax-type=\"texmath\"><span>$a, b, c, m, n$</span></span></img></span></span> for <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140603439","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 SUMMED PAPERFOLDING SEQUENCE","authors":"MARTIN BUNDER, BRUCE BATES, STEPHEN ARNOLD","doi":"10.1017/s0004972724000169","DOIUrl":"https://doi.org/10.1017/s0004972724000169","url":null,"abstract":"The sequence <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000169_inline1.png\" /> <jats:tex-math> $a( 1) ,a( 2) ,a( 3) ,ldots, $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> labelled A088431 in the <jats:italic>Online Encyclopedia of Integer Sequences</jats:italic>, is defined by: <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000169_inline2.png\" /> <jats:tex-math> $a( n) $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is half of the <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000169_inline3.png\" /> <jats:tex-math> $( n+1) $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>th component, that is, the <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000169_inline4.png\" /> <jats:tex-math> $( n+2) $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>th term, of the continued fraction expansion of <jats:disp-formula> <jats:alternatives> <jats:graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000169_eqnu1.png\" /> <jats:tex-math> $$ begin{align*} sum_{k=0}^{infty }frac{1}{2^{2^{k}}}. end{align*} $$ </jats:tex-math> </jats:alternatives> </jats:disp-formula> Dimitri Hendriks has suggested that it is the sequence of run lengths of the paperfolding sequence, A014577. This paper proves several results for this summed paperfolding sequence and confirms Hendriks’s conjecture.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140298196","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":"CHOQUET INTEGRALS, HAUSDORFF CONTENT AND FRACTIONAL OPERATORS","authors":"NAOYA HATANO, RYOTA KAWASUMI, HIROKI SAITO, HITOSHI TANAKA","doi":"10.1017/s000497272400011x","DOIUrl":"https://doi.org/10.1017/s000497272400011x","url":null,"abstract":"We show that the fractional integral operator <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline1.png\" /> <jats:tex-math> $I_{alpha }$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline2.png\" /> <jats:tex-math> $0&lt;alpha &lt;n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, and the fractional maximal operator <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline3.png\" /> <jats:tex-math> $M_{alpha }$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline4.png\" /> <jats:tex-math> $0le alpha &lt;n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, are bounded on weak Choquet spaces with respect to Hausdorff content. We also investigate these operators on Choquet–Morrey spaces. The results for the fractional maximal operator <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline5.png\" /> <jats:tex-math> $M_alpha $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> are extensions of the work of Tang [‘Choquet integrals, weighted Hausdorff content and maximal operators’, <jats:italic>Georgian Math. J.</jats:italic>18(3) (2011), 587–596] and earlier work of Adams and Orobitg and Verdera. The results for the fractional integral operator <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S000497272400011X_inline6.png\" /> <jats:tex-math> $I_{alpha }$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> are essentially new.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140170704","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 CHARACTERISATION OF SOLUBLE -GROUPS","authors":"ZHIGANG WANG, A-MING LIU, VASILY G. SAFONOV, ALEXANDER N. SKIBA","doi":"10.1017/s0004972724000157","DOIUrl":"https://doi.org/10.1017/s0004972724000157","url":null,"abstract":"Let <jats:italic>G</jats:italic> be a finite group. A subgroup <jats:italic>A</jats:italic> of <jats:italic>G</jats:italic> is said to be <jats:italic>S-permutable</jats:italic> in <jats:italic>G</jats:italic> if <jats:italic>A</jats:italic> permutes with every Sylow subgroup <jats:italic>P</jats:italic> of <jats:italic>G</jats:italic>, that is, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline2.png\" /> <jats:tex-math> $AP=PA$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline3.png\" /> <jats:tex-math> $A_{sG}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be the subgroup of <jats:italic>A</jats:italic> generated by all <jats:italic>S</jats:italic>-permutable subgroups of <jats:italic>G</jats:italic> contained in <jats:italic>A</jats:italic> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline4.png\" /> <jats:tex-math> $A^{sG}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be the intersection of all <jats:italic>S</jats:italic>-permutable subgroups of <jats:italic>G</jats:italic> containing <jats:italic>A</jats:italic>. We prove that if <jats:italic>G</jats:italic> is a soluble group, then <jats:italic>S</jats:italic>-permutability is a transitive relation in <jats:italic>G</jats:italic> if and only if the nilpotent residual <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline5.png\" /> <jats:tex-math> $G^{mathfrak {N}}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> of <jats:italic>G</jats:italic> avoids the pair <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline6.png\" /> <jats:tex-math> $(A^{s G}, A_{sG})$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, that is, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972724000157_inline7.png\" /> <jats:tex-math> $G^{mathfrak {N}}cap A^{sG}= G^{mathfrak {N}}cap A_{sG}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> for every subnormal subgroup <jats:italic>A</jats:italic> of <jats:italic>G</jats:italic>.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140155547","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 CLASS OF SYMBOLS THAT INDUCE BOUNDED COMPOSITION OPERATORS FOR DIRICHLET-TYPE SPACES ON THE DISC","authors":"ATHANASIOS BESLIKAS","doi":"10.1017/s0004972724000170","DOIUrl":"https://doi.org/10.1017/s0004972724000170","url":null,"abstract":"<p>We study the problem of determining the holomorphic self maps of the unit disc that induce a bounded composition operator on Dirichlet-type spaces. We find a class of symbols <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240313131113149-0098:S0004972724000170:S0004972724000170_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$varphi $</span></span></img></span></span> that induce a bounded composition operator on the Dirichlet-type spaces, by applying results of the multidimensional theory of composition operators for the weighted Bergman spaces of the bi-disc.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125032","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}