Showing 1 - 20 results of 42 for search '"F/X2"', query time: 1.61s Refine Results
  1. 1
  2. 2

    Inner product spaces and quadratic functional equations by Jae-Hyeong Bae, Batool Noori, M. B. Moghimi, Abbas Najati

    Published 2021-02-01
    “…Abstract In this paper, we introduce the functional equations f ( 2 x − y ) + f ( x + 2 y ) = 5 [ f ( x ) + f ( y ) ] , f ( 2 x − y ) + f ( x + 2 y ) = 5 f ( x ) + 4 f ( y ) + f ( − y ) , f ( 2 x − y ) + f ( x + 2 y ) = 5 f ( x ) + f ( 2 y ) + f ( − y ) , f ( 2 x − y ) + f ( x + 2 y ) = 4 [ f ( x ) + f ( y ) ] + [ f ( − x ) + f ( − y ) ] . …”
    Get full text
    Article
  3. 3

    Quantum differentiability of essentially bounded functions on Euclidean space by Lord, S, McDonald, E, Sukochev, F, Zanin, D

    Published 2017
    “…We prove the condition that the function x↦‖(∇f)(x)‖ 2 d :=((∂ 1 f)(x) 2 +…+(∂ d f)(x) 2 ) d/2 , x∈R d , being integrable is necessary and sufficient for the quantised derivative of f to belong to the weak Schatten d-class. …”
    Journal article
  4. 4

    The new investigation of the stability of mixed type additive-quartic functional equations in non-Archimedean spaces by Thanyacharoen Anurak, Sintunavarat Wutiphol

    Published 2020-07-01
    “…In this article, we prove the generalized Hyers-Ulam stability for the following additive-quartic functional equation:f(x+3y)+f(x−3y)+f(x+2y)+f(x−2y)+22f(x)+24f(y)=13[f(x+y)+f(x−y)]+12f(2y),f(x+3y)+f(x-3y)+f(x+2y)+f(x-2y)+22f(x)+24f(y)=13{[}f(x+y)+f(x-y)]+12f(2y),where f maps from an additive group to a complete non-Archimedean normed space.…”
    Get full text
    Article
  5. 5

    A rough differentiable function by Kirchheim, B, Mueller, P

    Published 2008
    “…A real-valued continuously differentiable function f on the unit interval is constructed such that Γk=1∞ βf(x,2-k)=∞ holds for every x ∈ [0, 1]. Here βf(x, 2-k) measures the distance of f to the best approximating linear function at scale 2-k around x. © 2008 by the authors.…”
    Journal article
  6. 6

    On the Stability of a Cubic Functional Equation in Random Normed Spaces by H. Azadi Kenary

    Published 2009-03-01
    “…Recently, the Hyers-Ulam-Rassias stability of the functional equation f(x + 2y) + f(x − 2y) = 2f(x) − f(2x) + 4n f(x + y) + f(x − y) o , has been proved in the case of Banach spaces. …”
    Get full text
    Article
  7. 7

    Fuzzy Stability of Quadratic Functional Equations by Dong Yun Shin, Choonkil Park, Sun-Young Jang, Jung Rye Lee

    Published 2010-01-01
    “…In this paper, we prove the generalized Hyers-Ulam stability of the following quadratic functional equations f(x+y)+f(x−y)=2f(x)+2f(y) and f(ax+by)+f(ax−by)=2a2f(x)+2b2f(y)  (a,b∈ℝ\{0},a≠±1) in fuzzy Banach spaces.…”
    Get full text
    Article
  8. 8

    On certain functional equation in prime rings by Fošner Maja, Marcen Benjamin, Vukman Joso

    Published 2022-04-01
    “…Let RR be prime ring of characteristic different from two and three, and let F:R→RF:R\to R be an additive mapping satisfying the relation F(x3)=F(x2)x−xF(x)x+xF(x2)F\left({x}^{3})=F\left({x}^{2})x-xF\left(x)x+xF\left({x}^{2}) for all x∈Rx\in R. …”
    Get full text
    Article
  9. 9

    Global maximal inequality to a class of oscillatory integrals by Ying Xue, Yaoming Niu

    Published 2018-12-01
    “…Abstract In the present paper, we give the global Lq $L^{q}$ estimates for maximal operators generated by multiparameter oscillatory integral St,Φ $S_{t,\varPhi}$, which is defined by St,Φf(x)=(2π)−n∫Rneix⋅ξei(t1ϕ1(|ξ1|)+t2ϕ2(|ξ2|)+⋯+tnϕn(|ξn|))fˆ(ξ)dξ,x∈Rn, $$S_{t,\varPhi}f(x)=(2\pi)^{-n} \int_{\mathbb{R}^{n}} e^{ix\cdot\xi}e^{i(t_{1} \phi_{1}(|\xi_{1}|)+t_{2}\phi_{2}(|\xi_{2}|)+ \cdots+t_{n}\phi_{n}(|\xi_{n}|))}\hat{f}(\xi)\,d\xi,\quad x\in\mathbb{R}^{n}, $$ where n≥2 $n\geq2$ and f is a Schwartz function in S(Rn) $\mathcal{S}(\mathbb {R}^{n})$, t=(t1,t2,…,tn) $t=(t_{1},t_{2},\ldots,t_{n})$, Φ=(ϕ1,ϕ2,…,ϕn) $\varPhi=(\phi_{1},\phi_{2},\ldots,\phi_{n})$, ϕi $\phi_{i}$ (i=1,2,3,…,n) $(i=1,2,3,\ldots, n)$ is a function on R+→R $\mathbb {R}^{+}\rightarrow\mathbb{R}$, which has a suitable growth condition. …”
    Get full text
    Article
  10. 10

    Stability of an Additive-Cubic-Quartic Functional Equation by M. Eshaghi-Gordji, S. Kaboli-Gharetapeh, Choonkil Park, Somayyeh Zolfaghari

    Published 2009-01-01
    “…In this paper, we consider the additive-cubic-quartic functional equation 11[f(x+2y)+f(x−2y)]=44[f(x+y)+f(x−y)]+12f(3y)−48f(2y)+60f(y)−66f(x) and prove the generalized Hyers-Ulam stability of the additive-cubic-quartic functional equation in Banach spaces.…”
    Get full text
    Article
  11. 11

    Stability of Mixed Type Cubic and Quartic Functional Equations in Random Normed Spaces by M. Eshaghi Gordji, M. B. Savadkouhi

    Published 2009-01-01
    “…We obtain the stability result for the following functional equation in random normed spaces (in the sense of Sherstnev) under arbitrary t-norms f(x+2y)+f(x−2y)=4[f(x+y)+f(x−y)]−24f(y)−6f(x)+3f(2y).…”
    Get full text
    Article
  12. 12

    On Some Uniform Bounds for Smooth Algebraic Functions by A. PARMEGGIANI

    Published 1995-01-01
    “…As a byproduct, it is shown that x !−→ (y −f(x))2, where f is a smooth algebraic function, behaves like a polynomial (in terms of scaling properties of averages and maxima). …”
    Get full text
    Article
  13. 13

    Stability Problems of Quintic Mappings in Quasi-β-Normed Spaces by In Goo Cho, Dongseung Kang, Heejeong Koh

    Published 2010-01-01
    “…We investigate the generalized Hyers-Ulam-Rassias stability problem in quasi-β-normed spaces and then the stability by using a subadditive function for the quintic function f:X→Y such that 2f(2x+y)+2f(2x−y)+f(x+2y)+f(x−2y)=20[f(x+y)+f(x−y)]+90f(x), for all x,y∈X.…”
    Get full text
    Article
  14. 14

    Remarks on solutions to the functional equations of the radical type by Janusz Brzdęk

    Published 2017-12-01
    “…Simple natural examples of them are the following two functional equations fn √xn + yn= f(x) + f(y),f n √xn + yn+ fn p|xn −yn|= 2f(x) + 2f(y) considered recently in several papers, for real functions and with given positive integer n, in connection with the notion of Ulam (or Hyers-Ulam) stability. …”
    Get full text
    Article
  15. 15

    Fixed Points and Hyers-Ulam-Rassias Stability of Cauchy-Jensen Functional Equations in Banach Algebras by Choonkil Park

    Published 2007-08-01
    “…We prove the Hyers-Ulam-Rassias stability of homomorphisms in real Banach algebras and of generalized derivations on real Banach algebras for the following Cauchy-Jensen functional equations: f(x+y/2+z)+f(x−y/2+z)=f(x)+2f(z), 2f(x+y/2+z)=f(x)+f(y)+2f(z), which were introduced and investigated by Baak (2006). …”
    Get full text
    Article
  16. 16

    New results on topological dynamics of antitriangular maps by Francisco Balibrea, J.S. Cánovas, A. Linero

    Published 2001-04-01
    “…We present some results concerning the topological dynamics of antitriangular maps, F:X2→ X2 with the formvF(x,y)=(g(y),f(x)), where (X,d) is a compact metric space and f,g : X→ X are continuous maps. …”
    Get full text
    Article
  17. 17

    An observation on spaces with a zeroset diagonal by Wei-Feng Xuan

    Published 2020-04-01
    “…A space $X$ has a zeroset diagonal if there is a continuous mapping $f X^2 \rightarrow[0,1]$ with $\Delta_X=f^{-1}(0)$, where $\Delta_X=\{(x,x)\colon x\in X\}$. …”
    Get full text
    Article
  18. 18

    Diagonals of separately continuous maps with values in box products by Karlova Olena, Mykhaylyuk Volodymyr

    Published 2018-03-01
    “…We prove that if X is a paracompact connected space and Z = ∏s∈S Zs is a product of a family of equiconnected metrizable spaces endowed with the box topology, then for every Baire-one map g : X → Z there exists a separately continuous map f : X2 → Z such that f (x, x) = g(x) for all x ∈ X.…”
    Get full text
    Article
  19. 19

    Fuzzy Stability of an Additive-Quadratic-Quartic Functional Equation by Choonkil Park

    Published 2010-01-01
    “…Using the fixed point method, we prove the generalized Hyers-Ulam stability of the following additive-quadratic-quartic functional equation: f(x+2y)+f(x−2y)=2f(x+y)+2f(−x−y)+2f(x−y)+2f(y−x)−4f(−x)−2f(x)+f(2y)+f(−2y)−4f(y)−4f(−y) in fuzzy Banach spaces.…”
    Get full text
    Article
  20. 20

    On stability of the functional equation of p-Wright affine functions in (2, α)-Banach spaces by El-sayed El-hady

    Published 2019-07-01
    “…Brzdęk and concerning the functional equation of the p-Wright affine function: f(p x 1+(1−p)x 2)+f((1−p)x 1+p x 2)=f(x 1)+f(x 2), can be proved also in (2, α)-Banach spaces, for some real number α∈(0,1). …”
    Get full text
    Article