Top Read Articles

    Published in last 1 year |  In last 2 years |  In last 3 years |  All
    Please wait a minute...
    Blow-Up of the Smooth Solutions to the Quantum Navier-Stokes-Landau-Lifshitz Equations
    Zhen Qiu,Guangwu Wang
    Acta mathematica scientia,Series A    2022, 42 (4): 1074-1088.  
    Abstract311)      PDF(pc) (346KB)(364)       Save

    In this paper, we investigate the blow-up of the smooth solutions to the quantum Navier-Stokes-Landau-Lifshitz systems(QNSLL) in the domains $\Omega \subseteq \mathbb{R} ^n(n =1, 2)$. We prove that the smooth solutions to the QNSLL will blow up in finite time in the domains half-space $\mathbb{R} _+^n$, whole-space $\mathbb{R} ^n$ and ball. The paper also shows that the blow-up time of the smooth solutions in half-space or whole-space only depends on boundary conditions, while the the blow-up time of the smooth solutions in the ball depends on initial data and boundary conditions. In particular, the above conclusions are also valid for NSLL systems.

    Reference | Related Articles | Metrics
    The General Inverse Bonnesen-Style Inequalities in $\mathbb{R}^n$
    Xu Dong,Yan Zhang,Chunna Zeng,Xingxing Wang
    Acta mathematica scientia,Series A    2022, 42 (3): 641-650.  
    Abstract260)   HTML12)    PDF(pc) (337KB)(260)       Save

    The isoperimetric problem plays an important role in integral geometry. In this paper we mainly investigate the inverse form of the isoperimetric inequality, i.e. the general inverse Bonnesen-type inequalities. The upper bounds of several new general isoperimetric genus are obtained. Futhermore, as corollaries, we get a series of classical inverse Bonnesen-type inequalities in the plane. Finally, the best estimate between the results of three upper bounds is given.

    Reference | Related Articles | Metrics
    The Schödinger Uncertainty Relation in the Fock-Type Spaces
    Li Wenxin,Lian Pan,Liang Yuxia
    Acta mathematica scientia,Series A    2023, 43 (5): 1321-1332.  
    Abstract224)   HTML20)    PDF(pc) (660KB)(448)       Save

    In this paper, the Schödinger uncertainty relation for the unilateral weighted shift operators on Fock space is established, and the explicit expression when the equality attained is given, which further extends the Heisenberg uncertainty relation on Fock space established in [4] and overcomes the difficulty in [16]. In addition, we generalize the uncertainty relation to the multiple operators case. A new uncertainty inequality in the form of non-self adjoint operators is obtained as well.

    Reference | Related Articles | Metrics
    The Bonnesen-type Inequalities for Plane Closed Curves
    Rui Bin,Xingxing Wang,Chunna Zeng
    Acta mathematica scientia,Series A    2022, 42 (6): 1601-1610.  
    Abstract212)   HTML9)    PDF(pc) (354KB)(230)       Save

    The isoperimetric inequality is one of the most classical geometric inequalities in differential geometry. The stability of isoperimetric genus can be characterized by Bonnesentype inequality and Bottema-type inequality. In this paper, via the method of differential geometry, Wirtinger inequality, Sachs inequality and divergence theorem and so on, we investigate the Bonnesen-type inequalities and Bottema-type inequalities for plane closed curves, and obtain a series of new Bonnesen-type inequalities and Bottema-type inequalities for curvature integration.

    Reference | Related Articles | Metrics
    Second Main Theorem for Algebraic Curves on Compact Riemann Surfaces
    Lizhen Duan,Hongzhe Cao
    Acta mathematica scientia,Series A    2021, 41 (6): 1585-1597.  
    Abstract210)   HTML13)    PDF(pc) (357KB)(290)       Save

    In this paper, we first establish some second main theorems for algebraic curves from a compact Riemann surface into a complex projective subvariety of the complex projective space, which is ramified over hypersurfaces in subgeneral position. Then we use it to study the ramification for the generalized Gauss map of complete regular minimal surfaces in $\mathbb{R}^{m}$ with finite total curvature.

    Reference | Related Articles | Metrics
    Approximate Optimality Conditions and Mixed Type Duality for a Class of Non-Convex Optimization Problems
    Jiaolang Wang,Donghui Fang
    Acta mathematica scientia,Series A    2022, 42 (3): 651-660.  
    Abstract201)   HTML4)    PDF(pc) (298KB)(175)       Save

    By using the properties of the Fréchet subdifferentials, we first introduce a new constraint qualification and then establish some approximate optimality conditions for the non-convex constrained optimization problem with objective function and/or constraint function being α-convex function. Moreover, some results for the weak duality, strong duality and converse-like duality theorems between this non-convex optimization problem and its mixed type dual problem are also given.

    Reference | Related Articles | Metrics
    Similarity and Unitary Similarity of a Class of Upper Triangular Operator Matrices
    Liqiong Lin,Jiahua Que,Yunnan Zhang
    Acta mathematica scientia,Series A    2022, 42 (5): 1281-1293.  
    Abstract196)   HTML18)    PDF(pc) (268KB)(278)       Save

    This paper introduces a class of upper triangular operator matrices related to Cowen-Douglas operators, and studies its similarity on Banach spaces and its unitary similarity on Hilbert spaces.

    Reference | Related Articles | Metrics
    Breather Wave Solutions, Lump Solutions and Semi-Rational Solutions of a Reduced (3+1)Dimensional Hirota Equation
    Chunmei Fang,Shoufu Tian
    Acta mathematica scientia,Series A    2022, 42 (3): 775-783.  
    Abstract196)   HTML1)    PDF(pc) (1085KB)(105)       Save

    In this paper, the long wave limit method is used to study the exact solutions of the (3+1)dimensional Hirota equation under dimensional reduction $z$=$x$. First, the bilinear form is constructed by using Bell polynomials. Based on the bilinear form, the $n$-order breather wave solutions are obtained under some parameter constraints on the $N$-order soliton solution. Secondly, by using the long wave limit method, high order lump wave solutions are obtained. Finally, the combined solutions of the first-order, second-order lump wave solutions and single solitary wave solutions are derived, i.e. semi-rational solutions. All the obtained solutions were analyzed with Maple software for physical characteristics.

    Table and Figures | Reference | Related Articles | Metrics
    Bonnesen-Style Inequalities for Star Bodies
    Zengle Zhang
    Acta mathematica scientia,Series A    2021, 41 (5): 1249-1262.  
    Abstract188)   HTML17)    PDF(pc) (351KB)(303)       Save

    Motivated by works of Lutwak and Petty[25-26, 37], a new star body ${\cal G}K$ associated with a given convex body $K$ is constructed. The isoperimetric inequality for ${\cal G}K$ and the reverse Bonnesen-style inequalities for K are established.

    Reference | Related Articles | Metrics
    Perturbations of Canonical Unitary Involutions Associated with Quantum Bernoulli Noises
    Nan Fan,Caishi Wang,Hong Ji
    Acta mathematica scientia,Series A    2022, 42 (4): 969-977.  
    Abstract186)   HTML4)    PDF(pc) (502KB)(199)       Save

    Quantum Bernoulli noises (QBN) are annihilation and creation operators acting on the space of square integrable Bernoulli functionals, which satisfy a canonical anti-commutation relation (CAR) in equal time and can play an important role in describing the environment of an open quantum system. In this paper, we address a type of perturbations of the canonical unitary involutions associated with QBN. We analyze these perturbations from a perspective of spectral theory and obtain exactly their spectra, which coincide with their point spectra. We also discuss eigenvectors of these perturbations from an algebraic point of view and unveil the structures of the subspaces consisting of their eigenvectors. Finally, as application, we consider the abstract quantum walks driven by these perturbations and obtain infinitely many invariant probability distributions of these walks.

    Reference | Related Articles | Metrics
    An Extension of Minkowski Formulae for Free Boundary Hypersurfaces in a Ball
    Sheng Weimin, Wang Yinhang
    Acta mathematica scientia,Series A    2023, 43 (6): 1641-1648.  
    Abstract177)   HTML18)    PDF(pc) (508KB)(349)       Save

    In this article, we prove a generalization of Hsiung-Minkowski formula for free boundary hypersurfaces in a ball in space forms. As corollaries, we obtain some Alexandrov-type results.

    Table and Figures | Reference | Related Articles | Metrics
    Complex Symmetry for a Class of Truncated Hankel Operators
    Liling Lai,Jinjin Liang,Yong Chen
    Acta mathematica scientia,Series A    2022, 42 (4): 961-968.  
    Abstract174)   HTML8)    PDF(pc) (293KB)(233)       Save

    The truncated Hankel operator is the compression to the model space of Hankel operator on the Hardy space. In this paper, the complex symmetry for a class of truncated Hankel operators is studied and the complete characterization is given. The obtained results show that, the complex symmetry of truncated Hankel operator may be related to the model space only, or to the model space and the symbol function of the operator both.

    Reference | Related Articles | Metrics
    Robust Accessible Hyperbolic Repelling Sets
    Xiao Jianrong
    Acta mathematica scientia,Series A    2024, 44 (1): 1-11.  
    Abstract173)   HTML10)    PDF(pc) (800KB)(279)       Save

    By operating Denjoy like surgery on a piecewise linear map, we constructed a family of$C^1$maps$f_\alpha \ (1<\alpha<3 )$admitting the following properties:

    1)$f_\alpha$admits a hyperbolic repelling Cantor set$\mathcal{A}_\alpha$with positive Lebesgue measure, and$\mathcal{A}_\alpha$is also a wild attractor of$f_{\alpha}$;

    2) The attractor$\mathcal{A}_\alpha$is accessible: the difference set$\mathbb{B}(A_\alpha)\backslash A_\alpha$between the basin of attraction$\mathbb{B}(A_\alpha)$and$A_\alpha$has positive Lebesgue measure;

    3) The family is structurally stable:$f_{\alpha}$is topologically conjugate to$f_{\alpha'}$for all$1<\alpha,\ \alpha'<3$.

    The surgery involves blowing up the discontinuity and its preimages set into open intervals. The$C^1$smoothness of$f_{\alpha}$is ensured by the prescribed lengths of glued intervals and the maps defined on the glued intervals.

    Table and Figures | Reference | Related Articles | Metrics
    Normal Family Theorems for Meromorphic Functions with Discrete Values of One Leaf
    Xiaojing Guo,Fujie Chai,Daochun Sun
    Acta mathematica scientia,Series A    2021, 41 (6): 1598-1605.  
    Abstract172)   HTML4)    PDF(pc) (313KB)(203)       Save

    In this paper, the normal theorems of meromorphic functions involving discrete values are studied by using the theory of Ahlfors covering surfaces. Firstly, the discrete values with one leaf of meromorphic functions are defined, then the inequalities about islands are investigated and two precise inequalities about islands are obtained. Finally, the inequalities are used to study the discrete values and the normal family of meromorphic functions, then a normal theorem involving a monophyletic island and a normal theorem involving discrete values of one leaf are obtained. All these theorems promote the famous Ahlfors' five islands theorem and five single valued theorem of Nevanlinna.

    Reference | Related Articles | Metrics
    Dynamics of an Anthrax Epidemiological Model with Time Delay and Seasonality
    Tailei Zhang,Junli Liu,Mengjie Han
    Acta mathematica scientia,Series A    2022, 42 (3): 851-866.  
    Abstract169)   HTML3)    PDF(pc) (480KB)(125)       Save

    In this paper, we developed a time-delayed epidemiological model to describe the anthrax transmission, which incorporates seasonality and the incubation period of the animal population. The basic reproduction number $R_{0}$ can be obtained. It is shown that the threshold dynamics is completely determined by the basic reproduction number. If $R_{0}<1$, the disease-free periodic solution is globally attractive and the disease will die out; if $R_{0} >1$, then there exists at least one positive periodic solution and the disease persists. We further investigate the corresponding autonomous system, the global stability of the disease-free equilibrium and the positive equilibrium is established in terms of $[R_0]$. Numerical simulations are carried out to investigate the sensitivity of $R_0$ about the parameters, the effects of vaccination and carcass disposal on controlling the spread of anthrax is also analyzed.

    Table and Figures | Reference | Related Articles | Metrics
    α-Robust Optimal Investment Strategy for Target Benefit Pension Plans Under Default Risk
    Yuan Shi,Yongxia Zhao
    Acta mathematica scientia,Series A    2022, 42 (3): 943-960.  
    Abstract166)   HTML1)    PDF(pc) (560KB)(134)       Save

    This paper considers the optimal investment and benefit payment problem for target benefit pension plan with default risk and model uncertainty. We assume that pension funds are invested in a risk-free asset, a defaultable bond and a stock satisfied a constant elasticity of variance(CEV) model. The payment of pensions depends on the financial status of the plan, with risk sharing between different generations. At the same time, in order to protect the rights of pension holders who dies before retirement, the return of premiums clauses is added to the model. In addition, our model allows the pension manager to have different levels of ambiguity aversion, instead of only considering extremely ambiguity-averse attitude. Using the stochastic optimal control approach, we establish the Hamilton-Jacobi-Bellman equations for both the post-default case and the pre-default case, respectively. We derive the closed-form solutions for α-robust optimal investment strategies and optimal benefit payment adjustment strategies. Finally, numerical analyses illustrate the influence of financial market parameters on optimal control problems.

    Table and Figures | Reference | Related Articles | Metrics
    Approximation Theorem and General Convergence of Population Games
    Huaxin Chen,Wensheng Jia
    Acta mathematica scientia,Series A    2021, 41 (5): 1566-1573.  
    Abstract158)   HTML1)    PDF(pc) (366KB)(208)       Save

    In this paper, we study whether the approximate solution of bounded rationality converges to the exact solution of complete rationality, which provides a theoretical support for the algorithm of population games. Firstly, under certain assumptions, the approximation theorem of population games under bounded rationality is proved. Then, by using the method of set-valued analysis and in the sense of Baire classification, we obtain the result that the solution of population games with perturbations on the objective function has generic convergence.

    Reference | Related Articles | Metrics
    The Two-Dimensional Steady Chaplygin Gas Flows Passing a Straight Wedge
    Jia Jia
    Acta mathematica scientia,Series A    2021, 41 (5): 1270-1282.  
    Abstract154)   HTML1)    PDF(pc) (349KB)(121)       Save

    The purpose of this paper is to investigate the two-dimensional steady supersonic chaplygin gas flows passing a straight wedge. By the definition of Radon measure solution, the accurate expressions are obtained for all cases where the Mach number is greater than 1. It is quite different from the polytropic gas, for the chaplygin gas flows passing problems, there exists a Mach number $ M^{\ast}_{0} $, when the Mach number of incoming flows is greater than or equal to $ M^{\ast}_{0} $, the quality will be concentrated on the surface of the straight wedge. At this time, there are not piecewise smooth solutions in the Lebesgue sense. The limit analysis is used to prove that the limit obtained by Lebesgue integral is consistent with the solution obtained in the sence of Radon measure solution.

    Reference | Related Articles | Metrics
    Dynamics Analysis of a Stochastic Glucose-Insulin Model
    Jiang Li,Guijie Lan,Shuwen Zhang,Chunjin Wei
    Acta mathematica scientia,Series A    2021, 41 (6): 1937-1949.  
    Abstract154)   HTML4)    PDF(pc) (591KB)(133)       Save

    In this paper, we investigate the global dynamics of a glucose-insulin model and its corresponding stochastic differential equation version. For the deterministic model, we show that there exists a unique equilibrium point, which is globally asymptotically stable for all parameter values. For the stochastic model, we show that the system admits unique positive global solution starting from the positive initial value and derive the stochastic permanence of the solutions of the stochastic system. In addition, by using Hasminskiis methods, we prove that there exists a unique stationary distribution and it has ergodicity. Finally, numerical simulations are carried out to support our theoretical results. It is found that: (ⅰ) the difficulty of the prediction of the peak size of the plasma glucose concentration always increases with the increase of the intensity of environmental fluctuations; (ⅱ) environmental fluctuations can result in the irregular oscillating of the plasma glucose concentration and plasma insulin concentration. Moreover, the volatility of the plasma glucose concentration and plasma insulin concentration always increase with the increase of the intensity of environmental fluctuations.

    Table and Figures | Reference | Related Articles | Metrics
    The Properties and Applications of the MP Weak Core Inverse
    Xiaoji Liu,Mengyue Liao,Hongwei Jin
    Acta mathematica scientia,Series A    2022, 42 (6): 1619-1632.  
    Abstract151)   HTML3)    PDF(pc) (338KB)(98)       Save

    In this paper, the concept of the Moore-Penrose weak Core inverse (MPWC inverse) is proposed based on the Moore-Penrose inverse and the weak Core inverse. It is described from algebraic and geometric perspectives respectively. The relationship between the MP weak Core inverse and the nonsingular bordered matrix is given. The expression of the MP weak Core inverse is given by using the Hartwig-Spindelböck decomposition and the Core-EP decomposition. The equivalence between the MP weak Core inverse of a matrix and EP matrix, the characterization and the perturbation analysis are given.

    Reference | Related Articles | Metrics