Uq(sl(2))的二维循环表示,C—G系数和一个自由费米子八顶角模型

明确地构造了量子代数U_q(Sl(2))当q=i和z中心扩张时的两维循环表示,此表示是既约的;给出了张量表示的C—G规则和C—G系数以及不同次序张量表示的扭结子(Intertwiner).此扭结子是一个满足自由费米子条件的八顶角R矩阵,因此给出了一个可积顶角模型.     

U_q（sl（2））的二维循环表示，C—G系数和一个自由费米子八顶角模型

明确地构造了量子代数Ｕｑ（Ｓｌ（２））当ｑ＝ｉ和ｚ中心扩张时的两维循环表示，此表示是既约的；给出了张量表示的Ｃ—Ｇ规则和Ｃ—Ｇ系数以及不同次序张量表示的扭结子（Ｉｎｔｅｒｔｗｉｎｅｒ）．此扭结子是一个满足自由费米子条件的八顶角Ｒ矩阵，因此给出了一个可积顶角模型．     

从夸克势模型研究核子-介子和ISOBAR-介子顶角函数

本文从在非相对论近似下得到的单胶子交换传递位出发, 用生成坐标方法计算了核子-介子和ISOBAR-介子的顶角函数. 顶角的耦合常数与实验符合得很好, 顶角的形状因子基本上是一个高斯型的分布.     

K介子衰变中的同位旋改变

在李政道的弱相互作用的W中间玻色子模型中,K介子的2π型衰变和三体轻子型衰变的最低级图形分别只能是图1(a)和图1(b)(s波的2π态不能与W组成同位旋标量,所以K→2π型衰变的最低级近似只有图1(a))。这模型假定了KWπ顶角服从同位旋选择规则|△Ⅰ|=1/2,而Wπ顶角满足|△Ⅰ|=0,从而保证了K→2π衰变中|△Ⅰ|=1/2。它同时预言     

在双色共振激光场中电子原子碰撞的自由-自由跃迁过程

研究了双色共振激光场中电子原子碰撞的自由-自由跃迁过程. 利用三能级模型和旋转波近似得到了靶原子的波函数, 在波恩近似的基础上进一步导出了多道碰撞的微分截面公式. 利用此公式计算了共振激光场中的激发碰撞对整个的碰撞贡献.     

开边界六顶角模型的边界关联函数

讨论了具有开边界六顶角模型的关联函数，计算了涉及边界自发极化的边界关联函数，得到了它们的行列式表示. 关键词： 六顶角模型 关联函数 开边界     

大天顶角的到达角起伏

基于修正Kolmogorov谱,运用相位结构函数的平方近似,导出了适用于大天顶角传输的到达角起伏方差及其功率谱的解析表达式.研究结果表明,新导出的方差表达式在任意天顶角都是适用的.散射盘尺度和接收孔径对到达角起伏起平滑作用,当接收孔径远大于散射盘尺度时,由于孔径平滑作用,导出的表达式在任意天顶角都可以近似为弱起伏理论给出的结果;当接收孔径小于散射盘尺度时,散射盘尺度的平滑作用明显,接收孔径的平滑作用相对较小,传统的到达角起伏理论仅在小天顶角是适用的,在大天顶角必须用新导出的方差表达式.当接收孔径D<25 cm时,弱起伏理论给出的表达式的适用范围被限制在小于50°~70°的天顶角内.     

含温有界原子模型下电子与离子碰撞激发和电离截面的理论研究

采用扭曲波玻恩交换近似方法，在自由原子模型下计算了电子与离子碰撞激发、电离截面，计算值与实验一致；在含温有界平均原子模型下，系统研究了不同温度、密度等离子体中离子的电子碰撞直接电离截面，发现由于温度、密度效应导致离子的能级漂移，引起等离子体中离子的碰撞电离截面比自由原子情形发生较大变化. 关键词： 平均原子模型 扭曲波波恩交换近似 电离截面     

液体理论中的Kirkwood变分方法的推广

本文克服了Cohen理论的缺点,对液体理论中Kirkwood变分方法作了推广。经过这样推广,格胞模型理论就可以系统地考虑分子运动关联性的任何级近似。把所得结果应用到一维情形,得到的自由能是严格正确的。应用到三维情形,最低级近似得LJD结果,一级近似得Taylor结果。     

波纹壁面降膜过程的一种近似模型

对高粘度液体在正弦形波纹壁面上的自由降落和蒸发建立了分析模型。对控制微分方程及边界条件作无量纲处理,引入流函数,采用摄动展开得到了0级近似和一级近似的微分方程组,讨论了液膜的流动和传热特性与壁面之间的关系。     

Domain wall partition function of the eight-vertex model with a non-diagonal reflecting end

With the help of the Drinfeld twist or factorizing F-matrix for the eight-vertex SOS model, we derive the recursion relations of the partition function for the eight-vertex model with a generic non-diagonal reflecting end and domain wall boundary condition. Solving the recursion relations, we obtain the explicit determinant expression of the partition function. Our result shows that, contrary to the eight-vertex model without a reflecting end, the partition function can be expressed as a single determinant.     

Eight-vertex model of the quasicrystal

The eight-vertex Baxter model of interacting spins is equivalent to two interacting Ising models. The ice-type ferroelectric model is a particular case. In this paper the eight-vertex model is solved exactly for the Penrose nonperiodic tiling of the plane.     

Symmetry relations in the sixteen-vertex model

We explore the consequences of the existence of a group of linear symmetry transformations for the sixteen-vertex model. An arbitrary sixteen-vertex model is shown tobe equivalent to a standard model, described in terms of ten parameters having an invariant significance. The general eight-vertex model is obtained when four of the invariant parameters vanish. Two further subciasses of the sixteen-vertex model are found to be equivalent to the eight-vertex model. The invariant conditions leading to the solved cases (i.e the general six-vertex, the free-fermion and the symmetric eight-vertex models) are given.     

The phase diagram of the 2D Ising model with anisotropic next-nearest-neighbor and four-spin interactions

In the present paper, the two-dimensional Ising model with anisotropic nearest-neighbor, next-nearest-neighbor and four-spin interactions has been studied. The ground states and energy of the model have been obtained. The model is equivalent to an eight-vertex model on its dual lattice. In some special cases, the model can be solved exactly as a zero-field eight-vertex model or a free-fermion model. Explicit phase diagrams are obtained exactly.     

Renormalization connection between the eight-vertex model and the gaussian model

A generalized version of the Villain model is defined which contains the eight-vertex model as a special case. A renormalization pattern is formulated in terms of this Villain model by which critical line(s) in the eight-vertex model are connected with the Gaussian fixed line. Gaussian equivalents are found for various operators along the Baxter line. The relation between the present results and those recently obtained by Kadanoff and Brown is discussed.     

Free field construction for the eight-vertex model: representation for form factors

The free field realization of the eight-vertex model is extended to form factors. It is achieved by constructing off-diagonal with respect to the ground state sectors matrix elements of the Λ operator which establishes a relation between corner transfer matrices of the eight-vertex model and of the SOS model. As an example, the two-particle form factor of the σ^z operator is evaluated explicitly.     

Free field construction for correlation functions of the eight-vertex model

A free field representation for the type I vertex operators and the corner transfer matrices of the eight-vertex model is proposed. The construction uses the vertex-face correspondence, which makes it possible to express correlation functions of the eight-vertex model in terms of correlation functions of the SOS model with a non-local insertion. This new non-local insertion admits a free field representation in terms of Lukyanov's screening operator. The spectrum of the corner transfer matrix and the Baxter-Kelland formula for the average staggered polarization have been reproduced.     

Drinfeld twist and the domain wall partition function of the eight-vertex model

With the help of the F-basis provided by the Drinfeld twist or factorising F-matrix for the spatial optical soliton model associated with the eight-vertex model, we calculate the partition function for the eight-vertex model on an N × N square lattice with domain wall boundary condition.     

Analytic theory of the eight-vertex model

We observe that the exactly solved eight-vertex solid-on-solid model contains an hitherto unnoticed arbitrary field parameter, similar to the horizontal field in the six-vertex model. The parameter is required to describe a continuous spectrum of the unrestricted solid-on-solid model, which has an infinite-dimensional space of states even for a finite lattice. The introduction of the continuous field parameter allows us to completely review the theory of functional relations in the eight-vertex/SOS-model from a uniform analytic point of view. We also present a number of analytic and numerical techniques for the analysis of the Bethe ansatz equations. It turns out that different solutions of these equations can be obtained from each other by analytic continuation. In particular, for small lattices we explicitly demonstrate that the largest and smallest eigenvalues of the transfer matrix of the eight-vertex model are just different branches of the same multivalued function of the field parameter.     

The six-vertex model eigenvectors as critical limit of the eight-vertex model bethe ansatz

The critical limit of the eight-vertex model eigenvectors obtained by means of the generalized Bethe Ansatz is shown to give the six-vertex eigenvectors as constructed in a previous paper by two of the authors. Furthermore, an explicit mapping is established between these eigenvectors and the usual Bethe Ansatz eigenvectors of the six-vertex model. This allows one to show that the indexv labeling the eight-vertex eigenstates becomes exactly the third component of the total spin in the critical limit.