双曲正弦函数与双曲余弦函数的推广

0前言正弦函数与余弦函数是大家常用的三角函数,它们还有一对“孪生”函数就是双曲正弦函数与双曲余弦函数,依次定义如下：其中常数e=2．7182818…,双曲函数在近代科学技术上有着广泛的应用．并且这两类“孪生”通数具有许多相似之处．最近笔者[1]对于正弦函数与余弦函数加以推广,本文继续探讨双曲正弦函数与双曲余弦函数的推广,即三维线性空间存在三个线性无关的函数组具有双曲正弦函数与双曲余弦函数的类似性质．1双曲函数推广关于双曲函数推广的问题,国外很早引起重视,但没有能够深入．Pipes[2.3]提出的定义,不仅是抽象的,还存…     

一元双曲分形插值

本文讨论了一元双曲分形插值,得到了二种一元双曲分形插值函数的构造方法,文「２」「３」「４」有关结论是它的特殊情况。     

双曲型Lagrangian函数*

双曲复数与Minkowski几何相对应,由四维时空间隔不变量和双曲型Lorentz变换可导出双曲型Lagrangian方程和Hamilton-Jacobi方程.     

四维Minkowski空间中类空超曲面的双曲高斯映射的奇点

介绍了四维Minkowski空间中类空超曲面的局部理论,定义了类空超曲面上的双曲高斯映射,双曲高度函数及距离平方函数,给出了一些定理的详细证明.介绍了一种证明高度函数是Morse族的新方法并应用Arnold等建立的Lagrange奇点理论对类空超曲面的双曲高斯映射的奇点进行了分类.     

3维双曲空间中曲面的双曲Gauss映照和法Gauss映照

本文导出了3维双曲空间中曲面的双曲Gauss映照和法Gauss映照的关系,发现了一般的曲面由双曲Gauss映照和平均曲率函数唯一确定,并证明了双曲Gauss映照所满足的二阶线性椭圆方程,给出了两种形式的关于双曲Gauss映照的三阶非线性偏微分方程(组)的一个解.     

涉及到三角函数和双曲函数的不等式链(英文)

证明了涉及到三角函数和双曲函数的不等式链.     

双曲域上的对数导数与Bloch函数

设Ω是有限复平面C上的双曲型区域,λ_Ω(z)|dz|是其上的双曲度量;置δ_Ω(z)=dist(z,Ω),[1/δ_Ω(z)]|dz|称为Ω上的拟双曲度量.又记Ω上的Bloch函数全体为B(Ω).本文引进了Ω上的对数可导函数空间T(Ω)和拟对数可导函数空间QT(Ω),并讨论了它们的一些性质.对数导函数区别λ_Ω(z)与1/δ_Ω(z),以及此时候T(Ω)的几何特征;T(Ω)与B(Ω)之间的关系;QT(Ω)的渐近特征.     

关于双曲函数的Huygens型不等式及应用

给出了关于双曲函数的Huygens型不等式,并得到了双曲函数的Wilker型不等式的加强.定义了一类新的Seiffert型平均,给出两个有关不等式.     

弱双曲覆盖映射的单一化结构稳定性

本文引入了弱双曲不变集的定义，给出弱双曲不变集的一些性质，并证明了弱双曲覆盖映射是单一化结构稳定的．     

关于双曲函数的两点注记

利用Euler公式及定积分的几何意义，诠释双曲函数与三角函数基本公式的相似性和双曲函数名称的一种由来。     

Hyperbolic Eisenstein series on n-dimensional hyperbolic spaces

We define a generalized hyperbolic Eisenstein series for a pair of a hyperbolic manifold of finite volume and its submanifold. We prove the convergence, the differential equation and the precise spectral expansion associated to the Laplace–Beltrami operator. We also derive the analytic continuation with the location of the possible poles and their residues from the spectral expansion.     

Hyperbolic Yamabe problem

In this paper, we investigate the solutions of the hyperbolic Yamabe problem for the(1 + n)-dimensional Minkowski space-time. More precisely speaking, for the case of n = 1, we derive a general solution of the hyperbolic Yamabe problem; for the case of n = 2, 3, we study the global existence and blowup phenomena of smooth solutions of the hyperbolic Yamabe problem;while for general multi-dimensional case n ≥ 2, we discuss the global existence and non-existence for a kind of exact solutions of the hyperbolic Yamabe problem.     

Hyperbolic polyhedral surfaces with regular faces

We study hyperbolic polyhedral surfaces with faces isometric to regular hyperbolic polygons satisfying that the total angles at vertices are at least 2π. The combinatorial information of these surfaces is shown to be identified with that of Euclidean polyhedral surfaces with negative combinatorial curvature everywhere. We prove that there is a gap between areas of non-smooth hyperbolic polyhedral surfaces and the area of smooth hyperbolic surfaces. The numerical result for the gap is obtained for hyperbolic polyhedral surfaces, homeomorphic to the double torus, whose 1-skeletons are cubic graphs.     

Hyperbolic beta integrals

Hyperbolic beta integrals are analogues of Euler's beta integral in which the role of Euler's gamma function is taken over by Ruijsenaars’ hyperbolic gamma function. They may be viewed as -bibasic analogues of the beta integral in which the two bases q and q? are interrelated by modular inversion, and they entail q-analogues of the beta integral for |q|=1. The integrals under consideration are the hyperbolic analogues of the Ramanujan integral, the Askey-Wilson integral and the Nassrallah-Rahman integral. We show that the hyperbolic Nassrallah-Rahman integral is a formal limit case of Spiridonov's elliptic Nassrallah-Rahman integral.     

Inverse Hyperbolic Problems with Time-Dependent Coefficients

We consider the inverse problem for the second order self-adjoint hyperbolic equation in a bounded domain in R ⁿ with lower order terms depending analytically on the time variable. We prove that, assuming the BLR condition, the time-dependent Dirichlet-to-Neumann operator prescribed on a part of the boundary uniquely determines the coefficients of the hyperbolic equation up to a diffeomorphism and a gauge transformation. As a by-product we prove a similar result for the nonself-adjoint hyperbolic operator with time-independent coefficients.     

Weyl and Lidski(i) Inequalities for General Hyperbolic Polynomials

The roots of hyperbolic polynomials satisfy the linear inequalities that were previously established for the eigenvalues of Hermitian matrices, after a conjecture by A. Horn. Among them are the so-called Weyl and Lidski(i) inequalities. An elementary proof of the latter for hyperbolic polynomials is given. This proof follows an idea from H. Weinberger and is free from representation theory and Schubert calculus arguments, as well as from hyperbolic partial differential equations theory.     

Evolutes of Hyperbolic Plane Curves

Abstract We define the notion of evolutes of curves in a hyperbolic plane and establish the relationships between singularities of these subjects and geometric invariants of curves under the action of the Lorentz group. We also describe how we can draw the picture of an evolute of a hyperbolic plane curve in the Poincaré disk.     

Boundary Value Problems for Degenerate Hyperbolic Systems of First Order Equations

In this paper we discuss some boundary value problems for degenerate hyperbolic complex equations of first order in a simply connected domain, in which the boundary value problems include the Riemann-Hilbert problem and the Cauchy problem. We first give the representation of solutions of the boundary value problems for the equations, and then prove the uniqueness and existence of solutions for the problems. In [A.V. Bitsadze (1988). Some Classes of Partial Differential Equations . Gordon and Breach, New York; A.V. Bitsadze and A.N. Nakhushev (1972). Theory of degenerating hyperbolic equations. Dokl. Akad. Nauk, SSSR , 204 , 1289-1291 (Russian); M.H. Protter (1954). The Cauchy problem for a hyperbolic second order equation. Can. J. Math ., 6 , 542-553], the authors discussed some boundary value problems for hyperbolic equations of second order.     

Hyperbolic Programs, and Their Derivative Relaxations

We study the algebraic and facial structures of hyperbolic programs, and examine natural relaxations of hyperbolic programs, the relaxations themselves being hyperbolic programs.