It is shown that for pure Yang-Mills fields there is no lump phenomena if the total energy is infinite and diverges mildly in a certain sense. This improves the well-known classical result on the absence of a lump for the finite total energy case. Some exact lump solutions are obtained showing that the energy condition cannot be removed. The results are valid for more general fields.This work was supported by the Chinese Natural Science Foundation, the Chinese Fund of Doctor Programs, and the University of Paris VI, and University of Bourgogne. 相似文献
The relationship between harmonic maps from R2 to S2, H2, ST,1, S1,1(–1) and the ± sinh — Laplace, ± sine — Laplace equation is found respectively. Existence theorems of some boundary value problems for the above harmonic maps are obtained. In the cases of H2, S1,1(+1), S1,1(–1) the results are global.Research supported partially by the Institute for Applied Mathematics, Sonderforschungsbereich 72 of the University of Bonn 相似文献
Some theorems of Liouville''s type on harmonic maps from Euclidean space of conformal flat space with finite or slowly divergent energy have been obtained by the
first-named author and H.C.J. Sealey, respectively. In this paper , a more general theorem is proved, which includes their results as special cases. The technique is to use a conservation law for harmonic maps. 相似文献
It is proved that the auto-Bäcklund transformations for all generalized KdV equations of any order admit a unified and explicit form. The theorem of permutability is proved in a unified way, too. The coefficients of the whole hierarchies of KdV equations considered are functions oft. The solitons whose speeds depend ont have unified formulas, too. Thus, we obtain vibrating solitons, solitons having infinite collisions, etc. 相似文献
Origami has recently received wide attention, and the study on its dynamic characteristics remains a nascent field. The waterbomb origami is a common subtype of origami, and its base structure is treated as a bi-stable configuration in the literature. The systematical framework for modeling, simulation and dynamic analysis of the vibration for the waterbomb origami base is established in this paper. In the presented model, the motion of the waterbomb origami base is divided into two working patterns according to its geometric characteristic. The nonlinear governing equation of motion of the waterbomb origami base is formulated based on the Lagrange’s equation. The base’s free and forced responses can be calculated by using the fourth-order Runge–Kutta method. The developed model is validated by the results predicted by the simulation in ADAMS. With the developed theoretical framework, the base’s vertical effective stiffness and natural frequency of its linearized system are discussed to reveal their programmability with respect to the base’s structure and design parameters. Remarkably, the bifurcations of its equilibria, including the pitchfork, transcritical and (special) saddle-node bifurcations, are analyzed. Unlike the bi-stable configuration reported in the literature, the mono- and tri-stable configurations can also be realized by the base due to gravity. Furthermore, the complex nonlinear dynamic behaviors, including chaos, are revealed.