In this paper, the authors introduce the concept of h-quasiconvex functions on Carnot groups G. It is shown that the notions of h-quasiconvex functions and h-convex sets are equivalent and the L^∞ estimates of first ...In this paper, the authors introduce the concept of h-quasiconvex functions on Carnot groups G. It is shown that the notions of h-quasiconvex functions and h-convex sets are equivalent and the L^∞ estimates of first derivatives of h-quasiconvex functions are given. For a Carnot group G of step two, it is proved that h-quasiconvex functions are locally bounded from above. Furthermore, the authors obtain that h-convex functions are locally Lipschitz continuous and that an h-convex function is twice differentiable almost everywhere.展开更多
We investigate a model arising from biology, which is a hyperbolic- parabolic coupled system. First, we prove the global existence and asymptotic behavior of smooth solutions to the Cauchy problem without any smallnes...We investigate a model arising from biology, which is a hyperbolic- parabolic coupled system. First, we prove the global existence and asymptotic behavior of smooth solutions to the Cauchy problem without any smallness assumption on the initial data. Second, if the Hs ∩ Ll-norm of initial data is sufficiently small, we also establish decay rates of the global smooth solutions. In particular, the optimal L2 decay rate of the solution and the almost optimal L2 decay rate of the first-order derivatives of the solution are obtained. These results are obtained by constructing a new nonnegative convex entropy and combining spectral analysis with energy methods.展开更多
respectively, where r = 1, 2, … , n, and il, i2, … , is are positive integers. In this paper, the Schur convexity of Fn（X, r） and Gn（x, r） are discussed. As applications, by a bijective transformation of indepen...respectively, where r = 1, 2, … , n, and il, i2, … , is are positive integers. In this paper, the Schur convexity of Fn（X, r） and Gn（x, r） are discussed. As applications, by a bijective transformation of independent variable for a Schur convex function, the authors obtain Schur convexity for some other symmetric functions, which subsumes the main results in recent literature; and by use of the theory of majorization establish some inequalities. In particular, the authors derive from the results of this paper the Weierstrass inequalities and the Ky Fan＇s inequality, and give a generalization of Safta＇s conjecture in the n-dimensional space and others.展开更多
基金Project supported by the Science Foundation for Pure Research of Natural Sciences of the Education Department of Hunan Province (No. 2004c251)the Hunan Provincial Natural Science Foundation of China (No. 05JJ30006)the National Natural Science Foundation of China (No. 10471063).
文摘In this paper, the authors introduce the concept of h-quasiconvex functions on Carnot groups G. It is shown that the notions of h-quasiconvex functions and h-convex sets are equivalent and the L^∞ estimates of first derivatives of h-quasiconvex functions are given. For a Carnot group G of step two, it is proved that h-quasiconvex functions are locally bounded from above. Furthermore, the authors obtain that h-convex functions are locally Lipschitz continuous and that an h-convex function is twice differentiable almost everywhere.
文摘We investigate a model arising from biology, which is a hyperbolic- parabolic coupled system. First, we prove the global existence and asymptotic behavior of smooth solutions to the Cauchy problem without any smallness assumption on the initial data. Second, if the Hs ∩ Ll-norm of initial data is sufficiently small, we also establish decay rates of the global smooth solutions. In particular, the optimal L2 decay rate of the solution and the almost optimal L2 decay rate of the first-order derivatives of the solution are obtained. These results are obtained by constructing a new nonnegative convex entropy and combining spectral analysis with energy methods.
基金supported by the National Natural Science Foundation of China(Nos.11271118,10871061,11301172)the Nature Science Foundation of Hunan Province(No.12JJ3002)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(No.11A043)the Construct Program of the Key Discipline in Hunan Province
文摘respectively, where r = 1, 2, … , n, and il, i2, … , is are positive integers. In this paper, the Schur convexity of Fn（X, r） and Gn（x, r） are discussed. As applications, by a bijective transformation of independent variable for a Schur convex function, the authors obtain Schur convexity for some other symmetric functions, which subsumes the main results in recent literature; and by use of the theory of majorization establish some inequalities. In particular, the authors derive from the results of this paper the Weierstrass inequalities and the Ky Fan＇s inequality, and give a generalization of Safta＇s conjecture in the n-dimensional space and others.
