{"title":"Relative Non-cuspidality of Representations Induced from Split Parabolic Subgroups","authors":"S. Kato, K. Takano","doi":"10.3836/tjm/1502179309","DOIUrl":"https://doi.org/10.3836/tjm/1502179309","url":null,"abstract":"","PeriodicalId":48976,"journal":{"name":"Tokyo Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46310051","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":"Computational Approach to Enumerate Non-hyperelliptic Superspecial Curves of Genus 4","authors":"Momonari Kudo, Shushi Harashita","doi":"10.3836/tjm/1502179310","DOIUrl":"https://doi.org/10.3836/tjm/1502179310","url":null,"abstract":"In this paper we enumerate nonhyperelliptic superspecial curves of genus $4$ over prime fields of characteristic $ple 11$. Our algorithm works for nonhyperelliptic curves over an arbitrary finite field in characteristic $p ge 5$. We execute the algorithm for prime fields of $ple 11$ with our implementation on a computer algebra system Magma. Thanks to the fact that the cardinality of $mathbb{F}_{p^a}$-isomorphism classes of superspecial curves over $mathbb{F}_{p^a}$ of a fixed genus depends only on the parity of $a$, this paper contributes to the odd-degree case for genus $4$, whereas our previous paper contributes to the even-degree case.","PeriodicalId":48976,"journal":{"name":"Tokyo Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89579666","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":"Geometric Aspects of Lucas Sequences, I","authors":"Noriyuki Suwa","doi":"10.3836/TJM/1502179294","DOIUrl":"https://doi.org/10.3836/TJM/1502179294","url":null,"abstract":"We present a way of viewing Lucas sequences in the framework of group scheme theory. This enables us to treat the Lucas sequences from a geometric and functorial viewpoint, which was suggested by Laxton ⟨On groups of linear recurrences, I⟩ and by Aoki-Sakai ⟨Mod p equivalence classes of linear recurrence sequences of degree two⟩. Introduction The Lucas sequences, including the Fibonacci sequence, have been studied widely for a long time, and there is left an enormous accumulation of research. Particularly the divisibility problem is a main subject in the study on Lucas sequences. More explicitly, let P and Q be non-zero integers, and let (wk)k≥0 be the sequence defined by the linear recurrence relation wk+2 = Pwk+1 −Qwk with the intial terms w0, w1 ∈ Z. If w0 = 0 and w1 = 1, then (wk)k≥0 is nothing but the Lucas sequnces (Lk)k≥0 associated to (P,Q). The divisibility problem asks to describe the set {k ∈ N ; wk ≡ 0 mod m} for a positive integer m. The first step was certainly taken forward by Edouard Lucas [6] as the laws of apparition and repetition in the case where m is a prime number and (wk)k≥0 is the Lucas sequence, and there have been piled up various kinds of results after then. In this article we study the divisibility problem for Lucas sequences from a geometirc viewpoint, translating several descriptions on Lucas sequences into the language of affine group schemes. For example, the laws of apparition and repetition is formulated in our context as follows: Theorem(=Proposition 3.23+Theorem 3.25) Let P and Q be non-zero integers with (P,Q) = 1, and let w0, w1 ∈ Z with (w0, w1) = 1. Define the sequence (wk)k≥0 by the recurrence relation wk+2 = Pwk+1−Qwk with initial terms w0 and w1, and put μ = ordp(w 1−Pw0w1+Qw 0). Let p be an odd prime with (p,Q) = 1 and n a positive integer. Then we have the length of the orbit (w0 : w1)Θ in P(Z/pZ) = 1 (n ≤ μ) r(pn−μ) (n > μ) . Furthermore, there exists k ≥ 0 such that wk ≡ 0 mod pn if and only if (w0 : w1) ∈ (0 : 1).Θ in P1(Z/pnZ). Here Θ denotes the subgroup of G(D)(Z(p)) generated by β(θ) = (P/4Q, 1/4Q), and r(pν) denotes the rank mod pν of the Lucas sequence associated to (P,Q). ∗) Partially supported by Grant-in-Aid for Scientific Research No.26400024 2010 Mathematics Subject Classification Primary 13B05; Secondary 14L15, 12G05. 1","PeriodicalId":48976,"journal":{"name":"Tokyo Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49485628","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":"Diophantine Approximation by Negative Continued Fraction","authors":"Hiroaki Ito","doi":"10.3836/tjm/1502179364","DOIUrl":"https://doi.org/10.3836/tjm/1502179364","url":null,"abstract":"We show that the growth rate of denominator $Q_n$ of the $n$-th convergent of negative expansion of $x$ and the rate of approximation: $$ frac{log{n}}{n}log{left|x-frac{P_n}{Q_n}right|}rightarrow -frac{pi^2}{3} quad text{in measure.} $$ for a.e. $x$. In the course of the proof, we reprove known inspiring results that arithmetic mean of digits of negative continued fraction converges to 3 in measure, although the limit inferior is 2, and the limit superior is infinite almost everywhere.","PeriodicalId":48976,"journal":{"name":"Tokyo Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44477331","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":"On the Weak Leopoldt Conjecture and Coranks of Selmer Groups of\u0000 Supersingular Abelian Varieties in $p$-adic Lie Extensions","authors":"M. Lim","doi":"10.3836/tjm/1502179341","DOIUrl":"https://doi.org/10.3836/tjm/1502179341","url":null,"abstract":"Let $A$ be an abelian variety defined over a number field $F$ with supersingular reduction at all primes of $F$ above $p$. We establish an equivalence between the weak Leopoldt conjecture and the expected value of the corank of the classical Selmer group of $A$ over a $p$-adic Lie extension (not neccesasily containing the cyclotomic $Zp$-extension). As an application, we obtain the exactness of the defining sequence of the Selmer group. In the event that the $p$-adic Lie extension is one-dimensional, we show that the dual Selmer group has no nontrivial finite submodules. Finally, we show that the aforementioned conclusions carry over to the Selmer group of a non-ordinary cuspidal modular form.","PeriodicalId":48976,"journal":{"name":"Tokyo Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2020-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43452076","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}