Mediterranean Journal of Mathematics最新文献

In this paper, we study real hypersurfaces of the two Kähler surfaces ({mathbb {S}}^2times {mathbb {S}}^2) and ({mathbb {H}}^2times {mathbb {H}}^2.) As the main results, amongst others, we classify all such hypersurfaces whose normal Jacobi operators are parallel with respect to either the Levi-Civita connection or the k-generalized Tanaka–Webster connection.

In this paper, we mainly study the classification of global existence and blow-up of solutions to degenerate Kirchhoff problems for the initial energy at different conditions. Firstly, under subcritical or critical conditions, we find two invariant sets and obtain the threshold results of global existence or blow-up in finite time. Furthermore, we apply (omega )-limit to prove the existence of blow-up solutions for the supercritical initial energy case. Finally, we give two-sided estimates of asymptotic behavior when the source term is controlled by the diffusion term.

In this paper, we investigate the Hyers–Ulam stability of the coefficient multipliers on the Hardy space (H^2) and the Bergman space (A^2), meanwhile, we also investigate the Hyers–Ulam stability of the coefficient multipliers between the Bergman space (A^2) and the Hardy space (H^2). We give the necessary and sufficient condition for the coefficient multipliers to have the Hyers–Ulam stability on the Hardy space (H^2), on the Bergman space (A^2) and between the Bergman space (A^2) and the Hardy space (H^2), respectively. We also show that the best constant of Hyers–Ulam stability exists under different circumstances. Some results generalized the results of MacGregor and Zhu when (p=2) in MacGregor and Zhu article (Mathematika 42:413–426, 1995). Moreover, some illustrative examples are also discussed.

We introduce and thoroughly examine a novel approach grounded in B-spline techniques to address the solution of second-kind nonlinear Volterra integral equations. Our method revolves around the application of B-spline interpolation, incorporating innovative end conditions, and delving into the associated existence and error estimation aspects. Notably, we develop this technique separately for even and odd-degree splines, leading to super-convergent approximations, particularly significant when employing even-degree splines. This paper extends its commitment to a comprehensive analysis, delving deeply into the method’s convergence characteristics and providing insightful error bounds. To empirically validate our approach, we present a series of numerical experiments. These experiments underscore the method’s efficacy and practicality, showcasing numerical approximations that closely align with the anticipated theoretical outcomes. Our proposed method thus emerges as a promising and robust tool for addressing the challenging realm of nonlinear Volterra integral equations, bridging the gap between theoretical expectations and practical applications.

Let X be a nonsingular complex projective surface. Given a semistable non isotrivial fibration (f: X rightarrow mathbb {P}^{1}) with general non-hyperelliptic fiber of genus (gge 4), we show that, if the number of singular fibers is 5, then (gle 11), thus improving the previously known bound (gle 17). Furthermore, we show that, for each possible genus, the general fiber has gonality at most 5. The corresponding fibrations are described as the resolution of concrete pencils of curves on minimal rational surfaces.

We consider an eigenvalue problem for a double-phase differential operator with unbalanced growth. Using the Nehari method, we show that the problem has a continuous spectrum determined by the minimal eigenvalue of the weighted p-Laplacian.