フルテキストURL mjou_068_183_204.pdf
著者 Horiuchi, Ryo|
抄録 In this note, we investigate a mixture of combinatorial spectra and stratified simplicial sets, which would be thought of as a model of the spectrum objects of (∞,∞)-categories.
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 183
終了ページ 204
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_175_181.pdf
著者 Puthenpurakal, Tony J. |
抄録 Let R be a regular ring of dimension d containing a field K of characteristic zero. If E is an R-module let Assi E = {Q ∈ AssE | heightQ = i}. Let P be a prime ideal in R of height g. We show that if R/P satisfies Serre’s condition Ri then Assg+i+1 Hg+1P(R) is a finite set. As an application of our techniques we prove that if P is a prime ideal in R such that (R/P)q is regular for any non-maximal prime ideal q then HiP(R) has finitely many associate primes for all i.
キーワード local cohomology regular rings Rn condition
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 175
終了ページ 181
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_147_174.pdf
著者 Hagiwara, Tomomichi|
抄録 This paper aims at providing a new fundamental framework for the Wronskian theory by paying attention to the null space of the Wronski matrix. It is first shown that identical vanishing of the Wronskian leads to two different representations of vector-valued functions that lie in the null space of the Wronski matrix. It is further shown that they are algebraically linearly dependent, by which we are immediately led to a key identity in the Wronskian theory, derived only through very simple linear algebraic arguments. Most fundamental results on the Wronskian theory available in the literature can thus be obtained in a quite straightforward fashion with a very clear perspective, and hence the relevant arguments are believed to be of pedagogical value, too. Some further issues relevant to the null space viewpoint are also discussed, where some other results available in the literature are derived through the null space viewpoint in a somewhat strengthened form.
キーワード linear independence of functions Wronski matrix eigenspace determinants minors
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 147
終了ページ 174
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_139_146.pdf
著者 Horiuchi, Jun| Shimomoto, Kazuma|
抄録 The aim of this article is to investigate interrelated structures lying among three notable problems in commutative algebra. These are Lifting problem, Ascent/descent along associated graded rings, and Matijevic-Roberts type problem.
キーワード Associated graded ring integral closure Rees ring seminormality weak normality
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 139
終了ページ 146
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_113_137.pdf
著者 Ohara, Mariko|
抄録 The main objective is showing a variant of resolution theorem of connective Waldhausen K-theory in suitable situations. We construct two sequences of subcategories, one is consisting of finitely generated symmetric module spectra which satisfy the condition of the resolution theorem and the other is consisting of the corresponding ∞-subcategories of certain finitely generated module spectra. As an application, we construct a sequence of subcategories consisting of certain DG-modules satisfying the condition of a resolution theorem.
キーワード K-theory projective modules E∞-rings infinity category
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 113
終了ページ 137
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_089_111.pdf
著者 Kato, Ryo|
抄録 In [3], Hovey and Palmieri proved many interesing results around the Bousfield lattice of the stable homotopy caregory of spectra. In [4], the author, Shimomura and Tatehara defined monoidally distributive posets as a generalization of the Bousfield lattice. In this paper, we consider the retract problem and a subset admitting complete Boolean algebra structure of monoidally distributive posets. In the last section, we see that some results in [3] are given by our results in this paper.
キーワード Bousfield lattice Monoidal poset Retract problem
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 89
終了ページ 111
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_077_087.pdf
著者 Chikunji, Chiteng’a John|
抄録 Let R be a commutative completely primary finite ring with unique maximal ideal J such that J3 = {0} and J2 ̸= {0}. In this paper, we investigate and determine the structure of the group of units U(R) of the ring R of characteristic p3 without giving any conditions on the generators for the maximal ideal J or on the invariants of the ring R.
キーワード commutative finite rings unit groups
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 77
終了ページ 87
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_063_075.pdf
著者 Nosaka, Takefumi|
抄録 Given a 3-cocycle ψ in the cohomology of a finite group G, we can define the Dijkgraaf-Witten invariant of closed 3-manifolds. In this paper, we focus on the case where ψ is a 3-cocycle systematically transferred from the second Chern class of a complex representation of G, and show some procedures for computing the invariant, and clarify its topological interpretation under some conditions.
キーワード Group cohomology 3-manifold Chern classes splitting principle
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 63
終了ページ 75
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_013_062.pdf
著者 Gaucher, Philippe|
抄録 We identify Grandis’ directed spaces as a full reflective subcategory of the category of multipointed d-spaces. When the multipointed d-space realizes a precubical set, its reflection coincides with the standard realization of the precubical set as a directed space. The reflection enables us to extend the construction of the natural system of topological spaces in Baues-Wirsching’s sense from directed spaces to multipointed d-spaces. In the case of a cellular multipointed d-space, there is a discrete version of this natural system which is proved to be bisimilar up to homotopy. We also prove that these constructions are invariant up to homotopy under globular subdivision. These results are the globular analogue of Dubut’s results. Finally, we point the apparent incompatibility between the notion of bisimilar natural systems and the q-model structure of multipointed d-spaces and we give some suggestions for future works.
キーワード multipointed d-space globular subdivision directed path natural system bisimulation open map
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 13
終了ページ 62
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_068_001_012.pdf
著者 Komatsu, Toru|
抄録 In this paper we present an algorithm to make a generator of the quadratic subextension of an odd dihedral extension. As an application we solve the Galois group problem for the quintic polynomials given by Kishi and Yamada.
キーワード Dihedral extension quadratic subextension Galois theory
発行日 2026-01
出版物タイトル Mathematical Journal of Okayama University
68巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 1
終了ページ 12
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2026 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_133_147.pdf
著者 Nakagawa, Yuto| Nakano, Fumihiko|
抄録 K. Brown [1] studied the random to top shuffle (the Tsetlin libary) by semigroup method. In this paper, (i) we extend his results to the colored permutation groups, and (ii) we consider a q-analogue of Tsetlin library which is different from what is studied in [1]. In (i), the results also extends those results for the top to random shuffle [4],[5], [6] to arbitrary distribution of choosing cards, but we still have derangement numbers in the multiplicity of each eigenvalues. In (ii), a version of q-analogue of derangement numbers by Chen-Rota [3] appears in the multiplicity of eigenvalues.
キーワード Tsetlin library Left Regular Band colored permutation group
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 133
終了ページ 147
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_101_131.pdf
著者 Ohmoto, Toyokazu|
抄録 An alternating sign matrix (ASM for short) is a square matrix which consists of 0, 1 and −1. In this paper, we characterize an ASM by showing a bijection between alternating sign matrix and six vertex model, and a bijection between six vertex model and height function. In order to show these bijections, we define a triplet (ai,j , ci,j , ri,j) for each entry of an ASM. We also define a track for each index of height function, and state more properties of height function.
キーワード Alternating sign matrix six vertex model height function
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 101
終了ページ 131
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_075_099.pdf
著者 Yamagishi, Hiroyuki| Kametaka, Yoshinori|
抄録 The Sobolev inequality shows that the supremum of a function defined on a whole line is estimated from the above by constant multiples of the potential energy. Among such constants, the smallest constant is the best constant. If we replace a constant by the best constant in the Sobolev inequality, then the equality holds for the best function. The aim of this paper is to find the best constant and the best function. In the background, there is a bending problem of a string with a rectangular spring constant. The Green function is an important function because the best constant and the best function consist of the Green function.
キーワード Sobolev inequality Green function reproducing kernel
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 75
終了ページ 99
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_067_074.pdf
著者 Honda, Masanobu| Sakamoto, Takanori|
抄録 We assume that a basic field k has zero characteristic. We show that any Fitting class is serially coalescent for locally finite Lie algebras. We also show that any class X satisfying N ≤ X ≤ ˆGr (e.g. Ft, B, Z, Gr, lN, rN, `e(◁)ˆA, ˆe(◁)ˆA, `Gr) is locally serially coalescent for locally finite Lie algebras, and, for any locally finite Lie algebra L, the X-ser radical of L is locally nilpotent.
キーワード Lie algebra serial subalgebra locally coalescent class
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 67
終了ページ 74
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_053_065.pdf
著者 Harrington, Joshua| Jones, Lenny|
抄録 A polynomial f(x) ∈ Z[x] of degree N is called monogenic if f(x) is irreducible over Q and {1, θ, θ2, . . . , θN−1} is a basis for the ring of integers of Q(θ), where f(θ) = 0. Define F(x) := xm+Axm−1+B. In this article, we determine sets of conditions on m, A, and B, such that the power-compositional trinomial F(xpn) is monogenic for all integers n ≥ 0 and a given prime p. Furthermore, we prove the actual existence of infinite families of such trinomials F(x).
キーワード irreducible monogenic power-compositional trinomial
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 53
終了ページ 65
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_029_051.pdf
著者 Haraguchi, Tadayuki| Shimakawa, Kazuhisa|
抄録 We construct on the category of diffeological spaces a Quillen model structure having smooth weak homotopy equivalences as the class of weak equivalences.
キーワード Diffeological space Homotopy theory Model category
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 29
終了ページ 51
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_067_001_028.pdf
著者 Wakabayashi, Yasuhiro|
抄録 The present paper aims to generalize a result by H. Kaji on Gauss maps in positive characteristic and establish an interaction with the study of dormant opers and Frobenius-projective structures. We prove a correspondence between dormant opers on a smooth projective variety and closed immersions into a projective space with purely inseparable Gauss map. By using this, we determine the subfields of the function field of a smooth curve in positive characteristic induced by Gauss maps. Moreover, this correspondence gives us a Frobenius-projective structure on a Fermat hypersurface.
キーワード Gauss map Frobenius-projective structure dormant indigenous bundle oper
発行日 2025-01
出版物タイトル Mathematical Journal of Okayama University
67巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 1
終了ページ 28
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2025 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_066_171_187.pdf
著者 Tarmidi, Rani Sasmita|
抄録 In this work, we provide explicit conditions for the coeffi-cients of a symmetric truncated cubic to give a smooth tropical curve. We also examine non-smooth cases corresponding to some specific sub-division types.
キーワード tropical curves smooth tropical curves symmetric truncated cubic
発行日 2024-01
出版物タイトル Mathematical Journal of Okayama University
66巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 171
終了ページ 187
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2024 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_066_159_169.pdf
著者 Shiraishi, Densuke|
抄録 In this paper, we derive formulas of complex and ℓ-adic multiple polylogarithms, which have two aspects: a duality in terms of indexes and a reflection in terms of variables. We provide an algebraic proof of these formulas by using algebraic relations between associators arising from the S3-symmetry of the projective line minus three points.
キーワード multiple polylogarithm ℓ-adic Galois multiple polylogarithm duality-reflection formula
発行日 2024-01
出版物タイトル Mathematical Journal of Okayama University
66巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 159
終了ページ 169
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2024 by the Editorial Board of Mathematical Journal of Okayama University
フルテキストURL mjou_066_135_157.pdf
著者 Davis, Daniel G.|
抄録 Let n ≥ 1, p a prime, and T(n) any representative of the Bousfield class of the telescope v−1n F(n) of a finite type n complex. Also, let En be the Lubin-Tate spectrum, K(En) its algebraic K-theory spectrum, and Gn the extended Morava stabilizer group, a profinite group. Motivated by an Ausoni-Rognes conjecture, we show that there are two spectral sequences
IEs,t2 ⇒ πt−s((LT(n+1)K(En))hGn) ⇐ IIEs,t2
with common abutment π∗(−) of the continuous homotopy fixed points of LT(n+1)K(En), where IEs,t2 is continuous cohomology with coefficients in a certain tower of discrete Gn-modules. If the tower satisfies the Mittag-Leffler condition, then there are isomorphisms with continuous cochain cohomology groups:
IE∗,∗2 ≅ H∗cts(Gn, π∗(LT(n+1)K(En))) ≅ IIE∗,∗2.
We isolate two hypotheses, the first of which is true when (n, p) = (1, 2), that imply (LT(n+1)K(En))hGn ≃ LT(n+1)K(LK(n)S0). Also, we show that there is a spectral sequence
Hscts(Gn, πt(K(En) ⊗ T(n + 1))) ⇒ πt−s((K(En) ⊗ T(n + 1))hGn).
キーワード Algebraic K-theory spectrum continuous homotopy fixed point spectrum Lubin-Tate spectrum Morava stabilizer group homotopy fixed point spectral sequence telescopic localization
発行日 2024-01
出版物タイトル Mathematical Journal of Okayama University
66巻
1号
出版者 Department of Mathematics, Faculty of Science, Okayama University
開始ページ 135
終了ページ 157
ISSN 0030-1566
NCID AA00723502
資料タイプ 学術雑誌論文
言語 英語
著作権者 Copyright ©2024 by the Editorial Board of Mathematical Journal of Okayama University