권호 표지

Journal of the Korean Mathematical Society (대한수학회지)

Korean Mathematical Society

  • Bimonthly
  • /
  • 0304-9914(pISSN)
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  • 2234-3008(eISSN)

Aim & Scope

This journal endeavors to publish significant research of broad interests in pure and applied mathematics. One volume is published each year, and each volume consists of six issues (January, March, May, July, September, November).

http://jkms.kms.or.kr/submission KCI SCOPUS SCI SCIE

Volume 63 Issue 4

  1. Shuchao Li;Changlong Shen;Sishu Zhao 687
    https://doi.org/10.4134/JKMS.j240289 PDF
    Let 𝒢(m, C3) be the set of C3-free non-bipartite graphs of size m. When m is odd, Zhai and Shu [11] identified the unique graph among 𝒢(m, C3) having the largest spectral radius. Naturally, Zhai and Shu posed a question to characterise the graph among 𝒢(m, C3) having the largest spectral radius when m is even. Recently, Li, Feng and Peng [4] solved Zhai-Shu's question for even m ≥ 4.7 × 105. In this article, we aim to enhance their result for even m ≥ 70 by using a different approach. Our proof technique is mainly based on Cauchy's interlacing theorem of eigenvalues of a graph, and with the help of Ning and Zhai's triangle counting lemma in terms of both eigenvalues and the size of a graph, together with the quotient matrix theory and the extended eigenvector method from Lou, Lu and Huang [6].
  2. Seungsu Hwang;Marcio Santo;Gabjin Yun 707
    https://doi.org/10.4134/JKMS.j250165 PDF
    In this paper, we show that a closed n-dimensional generalized (λ, n+m)-Einstein manifold of constant scalar curvature is isometric to either a sphere 𝕊n, or a product 𝕊1 × Σn-1 of a circle with an (n - 1)-dimensional Einstein manifold of positive Ricci curvature, up to finite cover and rescaling, under the hypothesis that a geometric 2-form vanishes. Furthermore, if we assume (M, g) has positive isotropic curvature, M must be isometric to either a sphere 𝕊n, or a product 𝕊1 × 𝕊n-1 of a circle with an (n - 1)-sphere.
  3. Fatima-Zahra Guissi;Hwankoo Kim;Najib Mahdou 735
    https://doi.org/10.4134/JKMS.j250266 PDF
    Let R = ⊕α∈Γ Rα be a commutative ring graded by an arbitrary torsionless monoid Γ. We say that R is a graded almost valuation ring (gr-AV-ring) if, for every pair of homogeneous elements in R, there exists a positive integer n such that either an divides bn in R or bn divides an. In this paper, we first provide a complete characterization of graded almost valuation rings. Then, we investigate the transferability of this property to the graded amalgamation A ⋈f J. Our objective is to introduce new classes of Γ-graded rings that satisfy the aforementioned property.
  4. Marek Janasz;Piotr Pokora 753
    https://doi.org/10.4134/JKMS.j250358 PDF
    In this paper we study Cynk-Szemberg octic hyperplane arrangements from the perspective of homological properties of their derivation modules. In particular, we define the notion of the type of hyperplane arrangements that will be used in our characterization of rigid Cynk-Szemberg octic hyperplane arrangements. Moreover, we deliver a combinatorial non-freeness criterion for essential hyperplane arrangements in ℂ4.
  5. Binyu Wang;Zhichao Wang 773
    https://doi.org/10.4134/JKMS.j250365 PDF
    In this paper, we study the almost everywhere convergence results of Schrödinger operator with complex time along curves. We also consider the fractional cases. All results are sharp up to the endpoints.
  6. Shuang Mou;Wenhao Zhang 787
    https://doi.org/10.4134/JKMS.j250383 PDF
    In this paper, let 𝜇 be an α-homogeneous (α > 0) and translation invariant Borel measure. We investigate the non-even weighted logarithmic Minkowski problem for 𝜇 with continuous density in the discrete case.
  7. Manseob Lee 805
    https://doi.org/10.4134/JKMS.j250423 PDF
    For any diffeomorphism f : M → M of a compact smooth manifold M, we prove that if f has the robustly eventual shadowing property around Λ, then (i) f is structurally stable when Λ = M, (ii) Λ is hyperbolic when Λ = 𝓒𝓡(f) (the chain recurrent set), and (iii) Λ is hyperbolic when Λ is a transitive set. This generalizes the results of Sakai [23] and Lee, Moriyasu and Sakai [13].
  8. Mengqiu Shao;Yunyan Yang;Liang Zhao 821
    https://doi.org/10.4134/JKMS.j250429 PDF
    We are mainly concerned with the nonlinear p-Laplace equation -∆pu + 𝜌|u|p-2u = 𝜓(x, u) on a locally finite graph G = (V, E), where p belongs to (1, +∞). We obtain the existence of positive solutions and positive ground state solutions by using the mountain-pass theorem and the Nehari manifold respectively. Moreover, we also analyze the asymptotic behavior for a sequence of positive ground state solutions. Compared with all the existing relevant works, our results have made essential improvements in at least three aspects: (i) p can take any value in (1, +∞); (ii) the conditions on the graph G and the potential 𝜌 are relaxed; (iii) for the existence of positive solutions, the growth condition in previous works on the nonlinear term 𝜓(x, s) as s → +∞ is removed.
  9. Gye Hwan Jo;Daeyeoul Kim 849
    https://doi.org/10.4134/JKMS.j250462 PDF
    We investigate restricted convolution sums of divisor functions formed by coprime summation variables. For the nine classical Ramanujan pairs (k, h), we derive explicit formulas for Rk,h(pα) at prime powers. As a main application, we compute the exact p-adic valuation of Rk,h(pα) and demonstrate its linear growth with α.