Pub Date : 2024-06-04DOI: 10.1017/s0004972724000443
ANDRÉ CARVALHO
We prove that centralisers of elements in [finitely generated free]-by-cyclic groups are computable. As a corollary, given two conjugate elements in a [finitely generated free]-by-cyclic group, the set of conjugators can be computed and the conjugacy problem with context-free constraints is decidable. We pose several problems arising naturally from this work.
{"title":"COMPUTING CENTRALISERS IN [FINITELY GENERATED FREE]-BY-CYCLIC GROUPS","authors":"ANDRÉ CARVALHO","doi":"10.1017/s0004972724000443","DOIUrl":"https://doi.org/10.1017/s0004972724000443","url":null,"abstract":"<p>We prove that centralisers of elements in [finitely generated free]-by-cyclic groups are computable. As a corollary, given two conjugate elements in a [finitely generated free]-by-cyclic group, the set of conjugators can be computed and the conjugacy problem with context-free constraints is decidable. We pose several problems arising naturally from this work.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255302","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}
Pub Date : 2024-06-03DOI: 10.1017/s000497272400039x
HAN WANG, ZHI-WEI SUN
We determine the characteristic polynomials of the matrices $[q^{,j-k}+t]_{1le ,j,kle n}$ and $[q^{,j+k}+t]_{1le ,j,kle n}$ for any complex number $qnot =0,1$. As an application, for complex numbers $a,b,c$ with $bnot =0$ and $a^2not =4b$, and the sequence $(w_m)_{min mathbb Z}$ with $w_{m+1}=aw_m-bw_{m-1}$ for all $min mathbb Z$, we determine the exact value of
{"title":"CHARACTERISTIC POLYNOMIALS OF THE MATRICES WITH","authors":"HAN WANG, ZHI-WEI SUN","doi":"10.1017/s000497272400039x","DOIUrl":"https://doi.org/10.1017/s000497272400039x","url":null,"abstract":"<p>We determine the characteristic polynomials of the matrices <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$[q^{,j-k}+t]_{1le ,j,kle n}$</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:20240531111027021-0956:S000497272400039X:S000497272400039X_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$[q^{,j+k}+t]_{1le ,j,kle n}$</span></span></img></span></span> for any complex number <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline5.png\"><span data-mathjax-type=\"texmath\"><span>$qnot =0,1$</span></span></img></span></span>. As an application, for complex numbers <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline6.png\"><span data-mathjax-type=\"texmath\"><span>$a,b,c$</span></span></img></span></span> with <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline7.png\"><span data-mathjax-type=\"texmath\"><span>$bnot =0$</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:20240531111027021-0956:S000497272400039X:S000497272400039X_inline8.png\"><span data-mathjax-type=\"texmath\"><span>$a^2not =4b$</span></span></img></span></span>, and the sequence <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline9.png\"><span data-mathjax-type=\"texmath\"><span>$(w_m)_{min mathbb Z}$</span></span></img></span></span> with <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline10.png\"><span data-mathjax-type=\"texmath\"><span>$w_{m+1}=aw_m-bw_{m-1}$</span></span></img></span></span> for all <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111027021-0956:S000497272400039X:S000497272400039X_inline11.png\"><span data-mathjax-type=\"texmath\"><span>$min mathbb Z$</span></span></img></span></span>, we determine the exact value of <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255240","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}
Pub Date : 2024-06-03DOI: 10.1017/s000497272400042x
PRANJAL TALUKDAR
An integer partition of a positive integer n is called t-core if none of its hook lengths is divisible by t. Gireesh et al. [‘A new analogue of t-core partitions’, Acta Arith.199 (2021), 33–53] introduced an analogue $overline {a}_t(n)$ of the t-core partition function. They obtained multiplicative formulae and arithmetic identities for $overline {a}_t(n)$ where $t in {3,4,5,8}$ and studied the arithmetic density of $overline {a}_t(n)$ modulo $p_i^{,j}$ where $t=p_1^{a_1}cdots p_m^{a_m}$ and $p_igeq 5$ are primes. Bandyopadhyay and Baruah [‘Arithmetic identities for some analogs of the 5-core partition function’, J. Integer Seq.27 (2024), Article no. 24.4.5] proved new arithmetic identities satisfied by
Gireesh 等人['A new analogue of t-core partitions', Acta Arith.他们得到了 $overline {a}_t(n)$ 的乘法公式和算术等式,其中 $t in {3,4,5,8}$ 并研究了 $overline {a}_t(n)$ modulo $p_i^{,j}$ 的算术密度,其中 $t=p_1^{a_1}cdots p_m^{a_m}$ 和 $p_igeq 5$ 都是素数。Bandyopadhyay 和 Baruah [' Arithmetic identities for some analogs of the 5-core partition function', J. Integer Seq.27 (2024), 文章编号 24.4.5]证明了 $overline {a}_5(n)$ 所满足的新算术等式。我们研究了 $/overline {a}_t(n)$ modulo arbitrary powers of 2 and 3 for $t=3^alpha m$ 的算术密度,其中 $gcd (m,6)$=1.另外,利用小野和田口的一个结果['某些模块形式的 2-adic 属性及其在算术函数中的应用',Int.J. Number Theory 1 (2005), 75-101]关于赫克算子零点性的结果,我们证明了 $overline {a}_3(n)$ modulo arbitrary powers of 2 的无穷同余族。
{"title":"ARITHMETIC PROPERTIES OF AN ANALOGUE OF t-CORE PARTITIONS","authors":"PRANJAL TALUKDAR","doi":"10.1017/s000497272400042x","DOIUrl":"https://doi.org/10.1017/s000497272400042x","url":null,"abstract":"<p>An integer partition of a positive integer <span>n</span> is called <span>t</span>-core if none of its hook lengths is divisible by <span>t</span>. Gireesh <span>et al.</span> [‘A new analogue of <span>t</span>-core partitions’, <span>Acta Arith.</span> <span>199</span> (2021), 33–53] introduced an analogue <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111127147-0430:S000497272400042X:S000497272400042X_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$overline {a}_t(n)$</span></span></img></span></span> of the <span>t</span>-core partition function. They obtained multiplicative formulae and arithmetic identities for <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111127147-0430:S000497272400042X:S000497272400042X_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$overline {a}_t(n)$</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:20240531111127147-0430:S000497272400042X:S000497272400042X_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$t in {3,4,5,8}$</span></span></img></span></span> and studied the arithmetic density of <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111127147-0430:S000497272400042X:S000497272400042X_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$overline {a}_t(n)$</span></span></img></span></span> modulo <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111127147-0430:S000497272400042X:S000497272400042X_inline5.png\"><span data-mathjax-type=\"texmath\"><span>$p_i^{,j}$</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:20240531111127147-0430:S000497272400042X:S000497272400042X_inline6.png\"><span data-mathjax-type=\"texmath\"><span>$t=p_1^{a_1}cdots p_m^{a_m}$</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:20240531111127147-0430:S000497272400042X:S000497272400042X_inline7.png\"><span data-mathjax-type=\"texmath\"><span>$p_igeq 5$</span></span></img></span></span> are primes. Bandyopadhyay and Baruah [‘Arithmetic identities for some analogs of the 5-core partition function’, <span>J. Integer Seq.</span> <span>27</span> (2024), Article no. 24.4.5] proved new arithmetic identities satisfied by <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111127147-0430:S000497272400042X:S000497272400042X_inline8","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255701","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}
Pub Date : 2024-06-03DOI: 10.1017/s0004972724000406
ILPO LAINE, ZINELAABIDINE LATREUCH
We consider the existence problem of meromorphic solutions of the Fermat-type difference equation $$ begin{align*} f(z)^p+f(z+c)^q=h(z), end{align*} $$
where $p,q$ are positive integers, and h has few zeros and poles in the sense that $N(r,h) + N(r,1/h) = S(r,h)$. As a particular case, we consider $h=e^g$, where g is an entire function. Additionally, we briefly discuss the case where h is small with respect to f in the standard sense $T(r,h)=S(r,f)$.
我们考虑费马型差分方程 $$ begin{align*}f(z)^p+f(z+c)^q=h(z), end{align*}的同态解的存在性问题。其中,$p,q$ 为正整数,而 h 的零点和极点很少,即 $N(r,h) + N(r,1/h) = S(r,h)$。作为一种特殊情况,我们考虑 $h=e^g$,其中 g 是一次函数。此外,我们还简要讨论了 h 相对于 f 较小的情况,即标准意义上的 $T(r,h)=S(r,f)$。
{"title":"NOTES ON FERMAT-TYPE DIFFERENCE EQUATIONS","authors":"ILPO LAINE, ZINELAABIDINE LATREUCH","doi":"10.1017/s0004972724000406","DOIUrl":"https://doi.org/10.1017/s0004972724000406","url":null,"abstract":"<p>We consider the existence problem of meromorphic solutions of the Fermat-type difference equation <span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111227055-0589:S0004972724000406:S0004972724000406_eqnu1.png\"><span data-mathjax-type=\"texmath\"><span>$$ begin{align*} f(z)^p+f(z+c)^q=h(z), end{align*} $$</span></span></img></span></p><p>where <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111227055-0589:S0004972724000406:S0004972724000406_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$p,q$</span></span></img></span></span> are positive integers, and <span>h</span> has few zeros and poles in the sense that <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111227055-0589:S0004972724000406:S0004972724000406_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$N(r,h) + N(r,1/h) = S(r,h)$</span></span></img></span></span>. As a particular case, we consider <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111227055-0589:S0004972724000406:S0004972724000406_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$h=e^g$</span></span></img></span></span>, where <span>g</span> is an entire function. Additionally, we briefly discuss the case where <span>h</span> is small with respect to <span>f</span> in the standard sense <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240531111227055-0589:S0004972724000406:S0004972724000406_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$T(r,h)=S(r,f)$</span></span></img></span></span>.</p>","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255312","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}
Pub Date : 2024-05-20DOI: 10.1017/s0004972724000388
Juho Halonen
The tropical analogue of the lemma on the logarithmic derivative is generalised for noncontinuous tropical meromorphic functions, that is, piecewise linear functions that may have discontinuities. In addition, two Borel type results are generalised for piecewise continuous functions. With the generalisation of the tropical analogue of the lemma on the logarithmic derivative, several tropical analogues of Clunie and Mohon’ko type results are also automatically generalised for noncontinuous tropical meromorphic functions.
{"title":"A TROPICAL ANALOGUE OF THE LEMMA ON THE LOGARITHMIC DERIVATIVE","authors":"Juho Halonen","doi":"10.1017/s0004972724000388","DOIUrl":"https://doi.org/10.1017/s0004972724000388","url":null,"abstract":"\u0000 The tropical analogue of the lemma on the logarithmic derivative is generalised for noncontinuous tropical meromorphic functions, that is, piecewise linear functions that may have discontinuities. In addition, two Borel type results are generalised for piecewise continuous functions. With the generalisation of the tropical analogue of the lemma on the logarithmic derivative, several tropical analogues of Clunie and Mohon’ko type results are also automatically generalised for noncontinuous tropical meromorphic functions.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141121241","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}
Pub Date : 2024-05-20DOI: 10.1017/s0004972724000352
Scott T. Chapman, Joshua Jang, JASON MAO, Skyler Mao
Let M be a Puiseux monoid, that is, a monoid consisting of nonnegative rationals (under standard addition). In this paper, we study factorisations in atomic Puiseux monoids through the lens of their associated Betti graphs. The Betti graph of $b in M$ is the graph whose vertices are the factorisations of b with edges between factorisations that share at least one atom. If the Betti graph associated to b is disconnected, then we call b a Betti element of M. We explicitly compute the set of Betti elements for a large class of Puiseux monoids (the atomisations of certain infinite sequences of rationals). The process of atomisation is quite useful in studying the arithmetic of Puiseux monoids, and it has been actively considered in recent literature. This leads to an argument that for every positive integer n, there exists an atomic Puiseux monoid with exactly n Betti elements.
假设 M 是普伊塞克斯单元,即由非负有理数组成的单元(在标准加法下)。在本文中,我们将从相关贝蒂图的角度研究原子普伊塞克斯单元中的因式分解。M$ 中 $b 的贝蒂图是其顶点为 b 的因式的图,因式之间的边至少共享一个原子。如果与 b 关联的贝蒂图是断开的,那么我们称 b 为 M 的贝蒂元。我们明确计算了一大类 Puiseux monoids(某些有理数无限序列的原子化)的贝蒂元集合。原子化过程对研究 Puiseux 单元的算术非常有用,最近的文献也在积极考虑这个问题。这引出了一个论点,即对于每一个正整数 n,都存在一个原子 Puiseux 单元,它恰好有 n 个贝蒂元。
{"title":"ON THE SET OF BETTI ELEMENTS OF A PUISEUX MONOID","authors":"Scott T. Chapman, Joshua Jang, JASON MAO, Skyler Mao","doi":"10.1017/s0004972724000352","DOIUrl":"https://doi.org/10.1017/s0004972724000352","url":null,"abstract":"\u0000 Let M be a Puiseux monoid, that is, a monoid consisting of nonnegative rationals (under standard addition). In this paper, we study factorisations in atomic Puiseux monoids through the lens of their associated Betti graphs. The Betti graph of \u0000 \u0000 \u0000 \u0000$b in M$\u0000\u0000 \u0000 is the graph whose vertices are the factorisations of b with edges between factorisations that share at least one atom. If the Betti graph associated to b is disconnected, then we call b a Betti element of M. We explicitly compute the set of Betti elements for a large class of Puiseux monoids (the atomisations of certain infinite sequences of rationals). The process of atomisation is quite useful in studying the arithmetic of Puiseux monoids, and it has been actively considered in recent literature. This leads to an argument that for every positive integer n, there exists an atomic Puiseux monoid with exactly n Betti elements.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141121709","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}