Transport Theory for Friedberg-Lee Model

By means of correlation density matrix theory and in terms of Wigner distribution function for quark, we obtain the transport equation for Friedberg-Lee model, which includes the coUision terms consis ten tly.     

多体体系输运理论——反常扩散

主要介绍最近在多体体系输运理论的一些模型和动力学等工作, 特别是一些有关反常扩散方面的工作结果.     

Covariant Non-Equilibrium Transport Theory Solutions for RHIC

New numerical solutions of 3+1D covariant kinetic theory are reported for nuclear collisions in the energy domain E_cm200 AGeV. They were obtained using the MPC 0.1.2 parton transport code employing high parton subdivision to retain Lorentz covariance. The solutions are compared to those of relativistic hydrodynamics employing Cooper–Frye isotherm freeze-out. The transport solutions follow a different dynamical path than hydrodynamics due to large dissipative effects when pQCD scattering rates and HIJING initial conditions are assumed. The transport freeze-out four-volume is sensitive to the reaction rates. The final transverse momentum distributions are found to deviate by up to an order of magnitude from those of Cooper–Frye frozen hydrodynamics.     

Gauge Field Theory for Fermions

Inhomogeneous nonlinear gauge field theory for fermions is studied in detail. We show that the zagrangian of the standard model can be rewritten in terms of the nonlinear connection.     

Classical Transport Theory for a Gluon Plasma

The classical picture of a pure gluon plasma is given and classical transportequations for gluons in the system are derived and compared with quantumequations for gluons and classical equations for quarks.     

Triton Photodisintegration with Effective Field Theory

Effective field theory (EFT) has been recently used for the calculation of neutron–deuteron radiative capture at very low energies. We present here the use of EFT to calculate the two-body photodisintegration of the triton, considering the three-body force. The calculated cross section shows sharp rising from threshold to maximum about 0.88 mb at ~13 MeV and decreasing slightly to about 0.81 mb at ~19 MeV, in agreement with the experimental data. Our results are in good agreement with the experimental data and the other calculations using modern realistic two- and three-nucleon forces, like AV18/UrbanaIX potential.     

Mean-field Theory for Some Bus Transport Networks with Random Overlapping Clique Structure

Transport networks, such as railway networks and airport networks, are a kind of random network with complex topology. Recently, more and more scholars paid attention to various kinds of transport networks and try to explore their inherent characteristics. Here we study the exponential properties of a recently introduced Bus Transport Networks （BTNs） evolution model with random overlapping clique structure, which gives a possible explanation for the observed exponential distribution of the connectivities of some BTNs of three major cities in China. Applying mean-field theory, we analyze the BTNs model and prove that this model has the character of exponential distribution of the connectivities, and develop a method to predict the growth dynamics of the individual vertices, and use this to calculate analytically the connectivity distribution and the exponents. By comparing mean-field based theoretic results with the statistical data of real BTNs, we observe that, as a whole, both of their data show similar character of exponential distribution of the connectivities, and their exponents have same order of magnitude, which show the availability of the analytical result of this paper.     

超核的相对论平均场计算

利用相对论平均场方法计算了奇异、粲和底超核的部分性质,包括各种不同味的超核的单粒子能量以及其他一些静态性质,并对结果进行了比较.对各种味的重子的势阱深度和耦合常数做了估计,得到丰富的结果.建议寻找质量数大于10?0的粲超核.同时探讨了不同重子杂质对原子核芯性质的可能影响.     

质量算符和五维概率分布空间的规范场理论(英文)

鉴于量子场论中普遍存在的粒子产生和湮灭,把描述场量的独立变量个数从量子力学波函数的4个常规时空坐标推广到了5个,其中第5个独立变量对应为粒子的内禀固有时,但是粒子运动的背景还是4维的常规时空。在场函数中固有时之所以可以看作为独立于常规时空坐标的变量,不仅是量子物理所特有的概率性描述语言所允许的,而且有可能是描述量子场论中广泛存在的粒子产生和湮灭现象所必需的。与此对应,在量子场论中,引入了质量算符((?)=-i(?))。由此,自由费米场在推广到五维概率分布空间和引入质量算符的基础上,根据相互作用的规范原理,引入了矢量规范相互作用和标量规范相互作用,同时所有的基本粒子的质量项都由质量算符自然地呈现。在此物理图像下,原则上基本粒子的质量应该通过求解相互作用耦合下的质量算符的本征值得到。此外,理论中存在普遍耦合的标量规范场和质量算符天然地联系在一起,有可能和引力作用对应起来。     

Particle Trajectories for Quantum Field Theory

The formulation of quantum mechanics developed by Bohm, which can generate well-defined trajectories for the underlying particles in the theory, can equally well be applied to relativistic quantum field theories to generate dynamics for the underlying fields. However, it does not produce trajectories for the particles associated with these fields. Bell has shown that an extension of Bohm’s approach can be used to provide dynamics for the fermionic occupation numbers in a relativistic quantum field theory. In the present paper, Bell’s formulation is adopted and elaborated on, with a full account of all technical detail required to apply his approach to a bosonic quantum field theory on a lattice. This allows an explicit computation of (stochastic) trajectories for massive and massless particles in this theory. Also particle creation and annihilation, and their impact on particle propagation, is illustrated using this model.     

Cosmic Structure Formation with Kinetic Field Theory

Kinetic field theory (KFT) is a statistical field theory for an ensemble of classical point particles in or out of equilibrium. Its application to cosmological structure formation is reviewed. Beginning with the construction of a generating functional, it is described in detail how the theory needs to be adapted to an expanding spatial background and the homogeneous and isotropic, correlated initial conditions for cosmic structures. Based on the generating functional, three approaches are developed to nonlinear cosmic structures, which rest either on expanding an interaction operator, averaging the interaction term, or resumming perturbation terms. An analytic, parameter‐free equation for the nonlinear cosmic power spectrum is presented. It is explained how density profiles of bound structures and velocity power spectra can be derived from the theory. It is clarified how KFT relates to the BBGKY hierarchy. Kinetic field theory is then applied to fluids, reformulating KFT in terms of macroscopic quantities. The resulting resummation scheme is used to describe mixtures of gas and dark matter. Finally, it is discussed how KFT can be combined with modified theories of gravity. As an example for a noncosmological application, results are shown on the spatial correlation function of cold Rydberg atoms derived from KFT.     

Topological Field Theory and Computing with Instantons

It is well known that dynamical systems may be employed as computing machines. However, not all dynamical systems offer particular advantages compared to the standard paradigm of computation, in regard to efficiency and scalability. Recently, it was suggested that a new type of machines, named digital –hence scalable– memcomputing machines (DMMs), that employ non‐linear dynamical systems with memory, can solve complex Boolean problems efficiently. This result was derived using functional analysis without, however, providing a clear understanding of which physical features make DMMs such an efficient computational tool. Here, we show, using recently proposed topological field theory of dynamical systems, that the solution search by DMMs is a composite instanton. This process effectively breaks the topological supersymmetry common to all dynamical systems, including DMMs. The emergent long‐range order – a collective dynamical behavior– allows logic gates of the machines to correlate arbitrarily far away from each other, despite their non‐quantum character. We exemplify these results with the solution of prime factorization, but the conclusions generalize to DMMs applied to any other Boolean problem.     

等时量子输运理论

在普遍量子情形下,建立了协变Ｗｉｇｎｅｒ函数的能量矩的等时动力论链和链的截断方案,得到了与低阶矩相关的物理密度量的输运方程和约束方程,并且证明高阶矩都能通过低阶矩表示．     

Stationary Scattering Theory for a Charged Particles Transport Problem

We consider a nonautonomous transport problem, the modelization of the charge exchange dynamics in a monoatomic ionized gas, and apply scattering theory to its dynamics. The free dynamics corresponds to the evolution of the total distribution of particles (neutral plus ionized particles) and the perturbed dynamics corresponds to the evolution of the neutral particles, which is the solution of a nonautonomous transport problem. The existence of the time-dependent wave operators was proved by the first author. In the present paper we follow Howland's formalism in constructing a stationary scattering theory for this nonautonomous transport problem by studying the evolution equation. We prove the existence of the wave operators and by using the smooth perturbation technique we obtain the similarity between perturbed and unperturbed operators.     

Parametrized Field Theory

A theory is presented in which a field depends not only on spacetime coordinates x, but also on a Lorentz-invariant parameter . Such a theory is conceptually and technically simple and manifestly covariant at every step. The generator of evolution and the generator of spacetime translations and Lorentz transformations are obtained in a straightforward way. In the quantized theory the Heisenberg equation of motion is written in a covariant form and is equivalent to the field equation. The equal commutator between the field and its canonically conjugate momentum is just proportional to the spacetime function. Finally comparison with the conventional field theory is done, and it is found that the expectation value of the momentum operator in the on shell states is the same.     

Supermulticonformal Field Theory

In this paper we develop the superspacestructure of the multicomplex space MC_n forn = 2ⁿ. We extend the basic properties of themulticomplex analysis to n the case ofSMC_n ^N, called supermulticomplex spaces: this goes from the n superanalyticitycondition to the residue theorem. The formalism of 2Dsuperconformal field theory is also developed onSMC_n ^N. We then show that the nassociated superconformal symmetry is infinite dimensional and leads ton copies of super-Virasoro algebra. This results can beapplied to construct a free-field theory on the volumeof the (n – 1)-super-brane. A model of field theory describing a bosonic case is alsopresented.