• 제목/요약/키워드: Sub-structure

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STRUCTURE JACOBI OPERATORS OF SEMI-INVARINAT SUBMANIFOLDS IN A COMPLEX SPACE FORM II

  • Ki, U-Hang;Kim, Soo Jin
    • East Asian mathematical journal
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    • 제38권1호
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    • pp.43-63
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    • 2022
  • Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (φ, ξ, η, g) in a complex space form Mn+1(c). We denote by Rξ the structure Jacobi operator with respect to the structure vector field ξ and by ${\bar{r}}$ the scalar curvature of M. Suppose that Rξ is φ∇ξξ-parallel and at the same time the third fundamental form t satisfies dt(X, Y) = 2θg(φX, Y) for a scalar θ(≠ 2c) and any vector fields X and Y on M. In this paper, we prove that if it satisfies Rξφ = φRξ, then M is a Hopf hypersurface of type (A) in Mn+1(c) provided that ${\bar{r}-2(n-1)c}$ ≤ 0.

Ba(Mg1/3Nb2/3)O3 - La(Mg2/3Nb1/3)O3복합 페로브스카이트 화합물의 결정구조 (Crystal Structure of Ba(Mg1/3Nb2/3)O3 - La(Mg2/3Nb1/3)O3Complex Perovskite Compound)

  • 백종후;이미재;최병현;지미정;임은경;남산
    • 한국전기전자재료학회논문지
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    • 제17권7호
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    • pp.718-723
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    • 2004
  • Crystal structure of $(Ba-{1-x}La_x)[Mg_\frac{1+x}{3}}Nb_\frac{{2-x}{3}}]O_3$ (BLMN) ceramics with 0\leq1x \geq was investigated using synchrotron X-ray powder diffraction (XRD) and high reso(B $a_{l-x}$L $a_{x}$)[M $g_{(1+x)}$3/N $b_{(2-x)/3}$$O_3$lution transmission electron microscopy (HRTEM). When the La content, x, is above 0.1, the 1:2 ordered hexagonal structure found in Ba($Mg_\frac{1}{3}Nb_\frac{2}{3}})O_3$(BMN) was transformed into 1:1 ordered cubic structure. The 1:1 ordered cubic structure was maintained up to x=0.7. When x exceeded 0.7, however, BLMN was transformed into 1:1 ordered structure which has cation displacement and in-phase and anti-phase tilt of octahedra.

SEMI-INVARIANT SUBMANIFOLDS OF CODIMENSION 3 IN A COMPLEX SPACE FORM IN TERMS OF THE STRUCTURE JACOBI OPERATOR

  • Ki, U-Hang;Kurihara, Hiroyuki
    • 대한수학회논문집
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    • 제37권1호
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    • pp.229-257
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    • 2022
  • Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (𝜙, 𝜉, 𝜂, g) in a complex space form Mn+1(c), c ≠ 0. We denote by A and R𝜉 the shape operator in the direction of distinguished normal vector field and the structure Jacobi operator with respect to the structure vector 𝜉, respectively. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a scalar 𝜃(< 2c) and any vector fields X and Y on M. In this paper, we prove that if it satisfies R𝜉A = AR𝜉 and at the same time ∇𝜉R𝜉 = 0 on M, then M is a Hopf hypersurface of type (A) provided that the scalar curvature s of M holds s - 2(n - 1)c ≤ 0.

Integrability of the Metallic Structures on the Frame Bundle

  • Islam Khan, Mohammad Nazrul
    • Kyungpook Mathematical Journal
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    • 제61권4호
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    • pp.791-803
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    • 2021
  • Earlier investigators have made detailed studies of geometric properties such as integrability, partial integrability, and invariants, such as the fundamental 2-form, of some canonical f-structures, such as f3 ± f = 0, on the frame bundle FM. Our aim is to study metallic structures on the frame bundle: polynomial structures of degree 2 satisfying F2 = pF +qI where p, q are positive integers. We introduce a tensor field Fα, α = 1, 2…, n on FM show that it is a metallic structure. Theorems on Nijenhuis tensor and integrability of metallic structure Fα on FM are also proved. Furthermore, the diagonal lifts gD and the fundamental 2-form Ωα of a metallic structure Fα on FM are established. Moreover, the integrability condition for horizontal lift FαH of a metallic structure Fα on FM is determined as an application. Finally, the golden structure that is a particular case of a metallic structure on FM is discussed as an example.

STRUCTURE JACOBI OPERATOR OF SEMI-INVARINAT SUBMANIFOLDS IN COMPLEX SPACE FORMS

  • KI, U-HANG;KIM, SOO JIN
    • East Asian mathematical journal
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    • 제36권3호
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    • pp.389-415
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    • 2020
  • Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (𝜙, ξ, η, g) in a complex space form Mn+1(c), c ≠ 0. We denote by Rξ and R'X be the structure Jacobi operator with respect to the structure vector ξ and be R'X = (∇XR)(·, X)X for any unit vector field X on M, respectively. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a scalar 𝜃(≠ 2c) and any vector fields X and Y on M. In this paper, we prove that if it satisfies Rξ𝜙 = 𝜙Rξ and at the same time R'ξ = 0, then M is a Hopf real hypersurfaces of type (A), provided that the scalar curvature ${\bar{r}}$ of M holds ${\bar{r}}-2(n-1)c{\leq}0$.

A NEW CLASSIFICATION OF REAL HYPERSURFACES WITH REEB PARALLEL STRUCTURE JACOBI OPERATOR IN THE COMPLEX QUADRIC

  • Lee, Hyunjin;Suh, Young Jin
    • 대한수학회지
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    • 제58권4호
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    • pp.895-920
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    • 2021
  • In this paper, first we introduce the full expression of the Riemannian curvature tensor of a real hypersurface M in the complex quadric Qm from the equation of Gauss and some important formulas for the structure Jacobi operator Rξ and its derivatives ∇Rξ under the Levi-Civita connection ∇ of M. Next we give a complete classification of Hopf real hypersurfaces with Reeb parallel structure Jacobi operator, ∇ξRξ = 0, in the complex quadric Qm for m ≥ 3. In addition, we also consider a new notion of 𝒞-parallel structure Jacobi operator of M and give a nonexistence theorem for Hopf real hypersurfaces with 𝒞-parallel structure Jacobi operator in Qm, for m ≥ 3.

SPIN HALF-ADDER IN 𝓑3

  • HASAN KELES
    • Journal of Applied and Pure Mathematics
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    • 제5권3_4호
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    • pp.187-196
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    • 2023
  • This study is about spin half add operations in 𝓑2 and 𝓑3. The burden of technological structures has increased due to the increase in the use of today's technological applications or the processes in the digital systems used. This has increased the importance of fast transactions and storage areas. For this, less transactions, more gain and storage space are foreseen. We have handle tit (triple digit) system instead of bit (binary digit). 729 is reached in 36 in 𝓑3 while 256 is reached with 28 in 𝓑2. The volume and number of transactions are shortened in 𝓑3. The limited storage space at the maximum level is storaged. The logic connectors and the complement of an element in 𝓑2 and the course of the connectors and the complements of the elements in 𝓑3 are examined. "Carry" calculations in calculating addition and "borrow" in calculating difference are given in 𝓑3. The logic structure 𝓑2 is seen to embedded in the logic structure 𝓑3. This situation enriches the logic structure. Some theorems and lemmas and properties in logic structure 𝓑2 are extended to logic structure 𝓑3.