Results 11 to 20 of about 41 (41)
Strengthened inequalities for the mean width and the ℓ‐norm
Journal of the London Mathematical Society, Volume 104, Issue 1, Page 233-268, July 2021., 2021 Abstract Barthe proved that the regular simplex maximizes the mean width of convex bodies whose John ellipsoid (maximal volume ellipsoid contained in the body) is the Euclidean unit ball; or equivalently, the regular simplex maximizes the ℓ‐norm of convex bodies whose Löwner ellipsoid (minimal volume ellipsoid containing the body) is the Euclidean unit
Károly J. Böröczky +2 more
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From Hardy to Rellich inequalities on graphs
Proceedings of the London Mathematical Society, Volume 122, Issue 3, Page 458-477, March 2021., 2021 Abstract We show how to deduce Rellich inequalities from Hardy inequalities on infinite graphs. Specifically, the obtained Rellich inequality gives an upper bound on a function by the Laplacian of the function in terms of weighted norms. These weights involve the Hardy weight and a function which satisfies an eikonal inequality.
Matthias Keller +2 more
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The additive approximation on a four‐variate Jensen‐type operator equation
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 50, Page 3171-3187, 2003., 2003 We study the Hyers‐Ulam stability theory of a four‐variate Jensen‐type functional equation by considering the approximate remainder ϕ and obtain the corresponding error formulas. We bring to light the close relation between the β‐homogeneity of the norm on F∗‐spaces and the approximate remainder ϕ, where we allow p, q, r, and s to be different in ...
Jian Wang
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On the stability of the quadratic mapping in normed spaces
International Journal of Mathematics and Mathematical Sciences, Volume 25, Issue 4, Page 217-229, 2001., 2001 The Hyers‐Ulam stability, the Hyers‐Ulam‐Rassias stability, and also the stability in the spirit of Gavruţa for each of the following quadratic functional equations f(x + y) + f(x − y) = 2f(x) + 2f(y), f(x + y + z) + f(x − y) + f(y − z) + f(z − x) = 3f(x) + 3f(y) + 3f(z), f(x + y + z) + f(x) + f(y) + f(z) = f(x + y) + f(y + z) + f(z + x) are ...
Gwang Hui Kim
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Some discrete Poincaré‐type inequalities
International Journal of Mathematics and Mathematical Sciences, Volume 25, Issue 7, Page 479-488, 2001., 2001 Some discrete analogue of Poincaré‐type integral inequalities involving many functions of many independent variables are established. These in turn can serve as generators of further interesting discrete inequalities.
Wing-Sum Cheung
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On the stability of generalized gamma functional equation
International Journal of Mathematics and Mathematical Sciences, Volume 23, Issue 8, Page 513-520, 2000., 2000 We obtain the Hyers‐Ulam stability and modified Hyers‐Ulam stability for the equations of the form g(x + p) = φ(x)g(x) in the following settings: |g(x + p) − φ(x)g(x) | ≤ δ, | g(x + p) − φ(x)g(x) | ≤ ϕ(x), | (g(x + p)/φ(x)g(x)) − 1 | ≤ ψ(x). As a consequence we obtain the stability theorems for the gamma functional equation.
Gwang Hui Kim
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Stability of generalized additive Cauchy equations
International Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 11, Page 721-727, 2000., 2000 A familiar functional equation f(ax + b) = cf(x) will be solved in the class of functions f : ℝ → ℝ. Applying this result we will investigate the Hyers‐Ulam‐Rassias stability problem of the generalized additive Cauchy equation f(a1x1+⋯+amxm+x0)=∑i=1mbif(ai1x1+⋯+aimxm) in connection with the question of Rassias and Tabor.
Soon-Mo Jung, Ki-Suk Lee
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Qualitative Analysis of Coupled Fractional Differential Equations involving Hilfer Derivative
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022 In this manuscript, we have studied the coupled system of Hilfer fractional differential equations with non-local conditions. We have used the Leray-alternative Schauder’s and the Contraction principle to obtain the results on the existence and ...
Dhawan Kanika +2 more
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On a modified Hyers‐Ulam stability of homogeneous equation
International Journal of Mathematics and Mathematical Sciences, Volume 21, Issue 3, Page 475-478, 1998., 1998 In this paper, a generalized Hyers‐Ulam stability of the homogeneous equation shall be proved, i.e., if a mapping f satisfies the functional inequality ‖f(yx) − ykf(x)‖ ≤ φ(x, y) under suitable conditions, there exists a unique mapping T satisfying T(yx) = ytT(x) and ‖T(x) − f(x)‖ ≤ Φ(x).
Soon-Mo Jung
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On a general Hyers‐Ulam stability result
International Journal of Mathematics and Mathematical Sciences, Volume 18, Issue 2, Page 229-236, 1995., 1995 In this paper, we prove two general theorems about Hyers‐Ulam stability of functional equations. As particular cases we obtain many of the results published in the last ten years on the stability of the Cauchy and quadratic equation.
Costanz Borelli, Gian Luigi Forti
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