共查询到18条相似文献,搜索用时 156 毫秒
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本文提出对Власов-Poisson方程进行微扰处理的一种重整化方案。利用图形展开方法证明了该理论到任意阶微扰的可重整化性质。给出了重整化传播量的一般形式。分析了相干项和绝对非相干项的物理意义。给出了重整化介电函数的正确表示,并对它的意义做了讨论。通过和以往重整化理论的比较,指出这种重整化方案是一种真正的完全重整化。
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通过对〈j⊥·E⊥〉的直接微扰展开证明了在六级近似以内相干重整化理论满足非线性漂移波的能量守恒。
关键词: 相似文献
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利用Yamada微扰论结合重整微扰方法来计算非对称Anderson模型,得到了局域电子占据数、重整化因子、重整化的局域能级以及重整化参数关于裸参数的展开式.计算了局域电子态密度和低温杂质电导,还计算了磁场对它们的影响,这些结果适用于从弱耦合到强耦合的整个耦合强度区域.由于在哈密顿量中已经将局域能级进行了初步重整,采用的重整微扰方法比Hewson的重整微扰方法更适合于研究非对称Anderson模型.
关键词:
非对称Anderson模型
重整化
磁场 相似文献
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介子结合态本征方程中δ相互作用可用T矩阵进行非微扰重整化,深入理解重整化的一些基本问题:物理结果与重正化点的选取无关,T矩阵非微扰重整化的物理实质. Nonperturbative T-matrix renormalization of the relativistic eigen equation for meson mass spectra is described and the expressions for eigen mass spectra and eigen wave functions are given. 相似文献
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Poincare截面是反映经典系统是否达到混沌的有力手段,无规矩阵理论被看成是显示量子系统规则运动与不规则运动特征的有效方法.那么,当一个经典相点在混沌体系的某一能量面E0上的不变环面被全部破坏后,与这一相点所对应的中心能量E0等于E0的相干态波包在它所占据的量子系统的子空间中有何表现呢?以原子核Lipkin模型为例,用重整化约化方法,对SU(3)群的广义相干态所占据的量子子空间进行了约化后对其中有关量的随机性作了考察,结果表明,在这样的等效子空间内能级间距的涨落,等效哈密顿量的矩阵元以及从可积体系的子空间到这一等效子空间的一一映射的矩阵元的分布均与无规矩阵理论的预言相符合,从而为进一步研究经典部分可积体系的量子表现奠定了基础.
关键词: 相似文献
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氘代甲烷几何构型及物性的量子化学研究 总被引:1,自引:1,他引:0
用HF/6-31G**、密度泛函方法B3LYP/31G**、二级微扰MP2/6-31G**、四级微扰MP4/6-31G**方法对甲烷和氘代甲烷进行几何构型全优化,并将优化的结果与实验值进行比较.用上述4种方法对甲烷和氘代甲烷分子进行分子的振动基频计算.密度泛函、二级微扰、四级微扰优于HF/6-31G**,尤其是密度泛函、四级微扰方法.密度泛函方法所用的机时远小于微扰方法.不同方法计算所得的氘代甲烷振动频率值与实验值的最大误差为10.4%,最小误差为2.0%. 相似文献
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本文给出了高温等离子体中高频波激发低频磁场和离子声波强湍动过程的重整化理论,以便改善通常的弱非线性处理方法,从Vlasov-Maxwell方程组出发,在Fourier表象中得到了包含“最发散”和“次发散”效应互相耦合的高频和低频传播于重整化方程组,从而获得了高、低频振荡粒子重整化分布函数和场的耦合关系。在“最发散”重整化近似下,我们求解了高低频传播子方程组,得到了展开到v4(高频湍动场能密度与等离子体热能密度之比)一次方的近似解和重整化介电函数等表达式。然后,在Fourier逆变换下导得了我们所要的时空表用中重整化强湍动方程组。最后,作为一个说明重整化作用的例子,在一维稳态下求解了孤立子的形式。
关键词: 相似文献
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The charged current pion production induced by neutrinos in12C,16O and56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming
Δ dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of Δ in the nuclear
medium. The pion absorption effects have also been taken into account 相似文献
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Nicolas Papanicolaou 《Physics Reports》1976,24(4):229-313
We present a self-contained treatment of the infrared problem in Quantum Electrodynamics. Our program includes a derivation and proof of finiteness of modified reduction formulae for scattering in Coulomb potentials and unitary extensions of the relativistic Coulomb amplitudes in the forward direction. The renormalization structure of the theory is discussed in connection with the infrared problem and the renormalization group is reconsidered and shown to be inadequate for the “improvement” of perturbation theoretic results. However, simple forms of the renormalization group equations are easily established, which allow for a simple discussion of the renormalization structure and the extraction of physical quantities out of Green functions normalized at an arbitrary mass μ < m (m is the fermion mass). As an example of such a quantity we consider the construction of a renormalized and infrared finite mass-operator in presence of external fields. Scattering theory in Quantum Electrodynamics is elaborated in the context of the coherent state formulation of the asymptotic condition. Dimensional regularization techniques are systematically used for the reduction of coherent states and the construction of S-matrix elements and the cross-section formulae. The latter are obtained in a relatively simple form, which allows for a direct comparison with the exact cross-section formulae derived in the traditional context. This establishes the equivalence of the two approaches at the cross-section level. Various applications illustrate the techniques presented here and relative topics are discussed. 相似文献
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M. Takatsuji 《Physica A》1976,84(1):68-81
We present a second-order many-body perturbation approach to coherent radiation processes. The theory gives a unified view of several many-atom effects as eigenmodes of the interacting atom-field system. Two renormalization procedures are essential to perform our program; (complex) energy renormalization using a noncanonical transformation and light-velocity renormalization using Bogoliubov transformation for field operators. 相似文献
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强激光场中离子HD+光解离几率的相干控制 总被引:5,自引:5,他引:0
对含时薛定谔方程用短时传播子的对称分割法求得了非微扰的数值解,计算了强超短脉冲基频激光(波长306.7nm)与其三倍频激光作用下的离子HD+光解离的相干控制参量大小设该离子的初态为电子振动.基态其中的相干激发是共振的.二束光之间的相对相位变化从0到360°在基频和倍频激光强度各为5×1013W/cm2和5.09×108W/cm2情形下,发现相对相位为π时,光解离几率达到最大。 相似文献
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《Nuclear Physics B》1999,542(3):694-718
We apply the method of angular quantization to the calculation of the wave function renormalization constants in D1(1) affine Toda quantum field theories. A general formula for the wave function renormalization constants in ADE Toda field theories is proposed. We also calculate all one-particle form factors and some of the two-particle form factors of an exponential field. 相似文献
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Orthodox strong-coupling determinations of Tc neglect a class of vertex corrections to the self-energy which are important for self-consistency near a ferromagnetic singularity and which result in an effective enhancement or renormalization of the coherent part of the Green's function. Renormalization- modified formalisms yield order of magnitude agreement for the temperature of the A-transition in He3. 相似文献