Frontiers of Mathematics in China

ISSN 1673-3452

ISSN 1673-3576(Online)

CN 11-5739/O1

Postal Subscription Code 80-964

2018 Impact Factor: 0.565

   Online First

Administered by

, Volume 2 Issue 2

For Selected: View Abstracts Toggle Thumbnails
General Hardy’s inequalities for functions nonzero on the boundary
CHEN Zhihui, CHEN Zhihui, SHEN Yaotian, SHEN Yaotian
Front. Math. China. 2007, 2 (2): 169-181.  
https://doi.org/10.1007/s11464-007-0012-7

Abstract   PDF (200KB)
Consider Hardy s inequalities with general weight φ for functions nonzero on the boundary. By an integral identity in C1(image),define Hilbert spaces H1k(Ω, φ) called Sobolev-Hardy spaces with weight φ. As a corollary of this identity, Hardy s inequalities with weight φ in C1(image) follow. At last, by Hardy s inequalities with weight φ = 1, discuss the eigenvalue problem of the Laplace-Hardy operator with critical parameter (N - 2)2/4 in H11(Ω).
Related Articles | Metrics
Uniqueness of weak solutions of time-dependent 3-D Ginzburg-Landau model for superconductivity
FAN Jishan, GAO Hongjun
Front. Math. China. 2007, 2 (2): 183-189.  
https://doi.org/10.1007/s11464-007-0013-6

Abstract   PDF (132KB)
We prove the uniqueness of weak solutions of the time-dependent 3-D Ginzburg-Landau model for superconductivity with (ψ0,A0) " L2(Ω) initial data under the hypothesis that (ψ,A) " C([0, T]; L3(Ω)) using the Lorentz gauge.
Related Articles | Metrics
Perelman’s λ-functional and Seiberg-Witten equations
FANG Fuquan, ZHANG Yuguang
Front. Math. China. 2007, 2 (2): 191-210.  
https://doi.org/10.1007/s11464-007-0014-5

Abstract   PDF (265KB)
In this paper, we estimate the supremum of Perelman s λ-functional λM(g) on Riemannian 4-manifold (M,g) by using the Seiberg-Witten equations. Among other things, we prove that, for a compact Kähler-Einstein complex surface (M,J, g0) with negative scalar curvature, (i) if g1 is a Riemannian metric on M with λM(g1) = λM(g0), then Volg1(M) "e Volg0 (M). Moreover, the equality holds if and only if g1 is also a Kãhler-Einstein metric with negative scalar curvature. (ii) If {gt}, t " [-1, 1], is a family of Einstein metrics on M with initial metric g0, then gt is a Kãhler-Einstein metric with negative scalar curvature.
Related Articles | Metrics
Fractional generalized L関y random fields as white noise functionals
HUANG Zhiyuan, LI Peiyan
Front. Math. China. 2007, 2 (2): 211-226.  
https://doi.org/10.1007/s11464-007-0015-4

Abstract   PDF (225KB)
In this paper, we construct the fractional generalized Lévy random fields (FGLRF) as tempered white noise functionals. We find that this white noise approach is very effective in investigating the properties of these fields. Under some conditions, the fractional Lévy fields in the usual sense are obtained. In addition, we also present a method to construct the anisotropic fractional generalized Lévy random fields (AFGLRF).
Related Articles | Metrics
Algorithm for solving shifted skew-symmetric linear system
JIANG Erxiong
Front. Math. China. 2007, 2 (2): 227-242.  
https://doi.org/10.1007/s11464-007-0016-3

Abstract   PDF (184KB)
A new algorithm for solving a shifted skew-Hermitian linear system is presented and the corresponding convergence theorem is given. Some numerical examples are provided to demonstrate the algorithm.
Related Articles | Metrics
Pricing of perpetual American and Bermudan options by binomial tree method
LIN Jianwei, LIANG Jin
Front. Math. China. 2007, 2 (2): 243-256.  
https://doi.org/10.1007/s11464-007-0017-2

Abstract   PDF (521KB)
In this paper, we consider the binomial tree method for pricing perpetual American and perpetual Bermudan options. The closed form solutions of these discrete models are solved. Explicit formulas for the optimal exercise boundary of the perpetual American option is obtained. A nonlinear equation that is satisfied by the optimal exercise boundaries of the perpetual Bermudan option is found.
Related Articles | Metrics
A wide class of heavy-tailed distributions and its applications
SU Chun, HU Zhishui, CHEN Yu, LIANG Hanying
Front. Math. China. 2007, 2 (2): 257-286.  
https://doi.org/10.1007/s11464-007-0018-1

Abstract   PDF (285KB)
Let F(x) be a distribution function supported on [0,∞) with an equilibrium distribution function Fe(x). In this paper we pay special attention to the hazard rate function re(x) of Fe(x), which is also called the equilibrium hazard rate (E.H.R.) of F(x). By the asymptotic behavior of re(x) we give a criterion to identify F(x) to be heavy-tailed or light-tailed. Moreover, we introduce two subclasses of heavy-tailed distributions, i.e., M and M*, where M contains almost all the most important heavy-tailed distributions in the literature. Some further discussions on the closure properties of M and M* under convolution are given, showing that both of them are ideal heavy-tailed subclasses. In the paper we also study the model of independent difference ξ = Z - ?, where Z and ? are two independent and non-negative random variables. We give intimate relationships of the tail distributions of ξ and Z, as well as relationships of tails of their corresponding equilibrium distributions. As applications, we apply the properties of class M to risk theory. In the final, some miscellaneous problems and examples are laid, showing the complexity of characterizations on heavy-tailed distributions by means of re(x).
Related Articles | Metrics
Commutators on Lipschitz spaces and related function spaces
Zhijian Wu
Front. Math. China. 2007, 2 (2): 287-303.  
https://doi.org/10.1007/s11464-007-0019-0

Abstract   PDF (215KB)
We characterize the symbol functions so that the associated commutators with symbol functions and the Hilbert transform are bounded on Lipschitz space ∧pα, where 1 < p < " and 0 < α < 1/p. Properties of such symbols are also discussed.
Related Articles | Metrics
Automorphism groups of pointed Hopf algebras
YANG Shilin
Front. Math. China. 2007, 2 (2): 305-316.  
https://doi.org/10.1007/s11464-007-0020-7

Abstract   PDF (176KB)
The group of Hopf algebra automorphisms for a finite-dimensional semisimple cosemisimple Hopf algebra over a field k was considered by Radford and Waterhouse. In this paper, the groups of Hopf algebra automorphisms for two classes of pointed Hopf algebras are determined. Note that the Hopf algebras we consider are not semisimple Hopf algebras.
Related Articles | Metrics
Ruin probability for L関y risk process compounded by geometric Brownian motion
ZHAO Xianghua, YIN Chuancun
Front. Math. China. 2007, 2 (2): 317-327.  
https://doi.org/10.1007/s11464-007-0021-6

Abstract   PDF (173KB)
In this paper, we assume that the surplus of an insurer follows a L暍y risk process and the insurer would invest its surplus in a risky asset, whose prices are modeled by a geometric Brownian motion. It is shown that the ruin probabilities (by a jump or by oscillation) of the resulting surplus process satisfy certain integro-differential equations.
Related Articles | Metrics
10 articles