用时空线分析多普勒效应

采用描述波源运动，观察者运动及声波在静止空气中以声速传播的三组时空线，用几何方法导出多普勒公式，并通过时空线相交分析多普勒效应中观察者接收声波信号的时序及周期，着重讨论了一般文献中未曾涉及的不同条件下多普勒效应的结果及其物理意义。     

孪生子佯谬

本文从一个新的角度来阐释孪生子佯谬的症结所在，详细分析了由于双胞胎兄弟所在参考系的不对称性导致的荒谬结论，并在两个惯性系下分别做了计算，最后的结论是相同的，并不存在矛盾，同时印证了所有的惯性系是平权的这一大前提!     

闵氏几何法解析“双生子佯谬”及结果讨论

在闵可夫斯基四维时空中利用二维坐标图解析了双生子效应.特别对飞船转向所引起的同时线跃变而导致的地球人年龄的跃变作出了定量解析,得出了孪生子重逢时经历过加速运动的飞船人比可以看作为惯性系的地球人更年轻的绝对性结论.然后通过对解析结果的讨论并辅之以数值计算,给出了飞船往返飞行的两个不同阶段及全程在两个不同参考系的具体的观测结果.     

非线性腔中横模的时空不稳定

通过数值模拟研究了非线性腔的横向效应，非线性表现在光场通过放大介质时所引起的相位变化与强度有关，模拟结果显示，随着非线性系数的变化，腔中的光场分布表现丰富的时空不稳定行为，其中包括横模跳变，时空周期行为以及光学涡旋的出现。     

黑洞量子理论

简述引力场中物质的量子效应——黑洞的Ｈａｗｋｉｎｇ辐射，并进一步讨论黑洞的量子理论，给出一些结论。     

一般稳态时空中光子的轨道效应

计算了带有电荷和磁荷的旋转场源外部稳态时空中光子的轨道效应. 通过对计算结果的分析, 发现由荷电所引起的光子轨道偏转效应将减小由场源质量所引起的光子轨道偏转效应,但由场源的旋转所引起的相应偏转效应将依赖于场源的旋转方向与光子运动方向之间的夹角. 通过对相应的天体参数的讨论得到了一系列有意义的结果. 关键词： 光子轨道 引力效应 稳态时空     

超短脉冲Bessel 光束和空间诱导色散效应

 给出了含时的波动方程的一族特解－超短脉冲Bessel光束，其脉冲光束的空间和时间部分可以做分离变量，空间部分在传输过程中保持Bessel光束不变，而时间脉冲部分的传输行为类似于在普通色散介质中的传输，此效应被称之为空间诱导色散效应。     

共振原子蒸气中激光脉冲的时空特性

在柱对称条件下，利用耦合的布洛赫－麦克斯韦方程，研究了激光脉冲在原子蒸气介质中的共振传播。考察了脉中在时空中的演化。数值计算结果表明激光脉冲在传播中，由于自感应透明与光波的衍射效应，表现出复杂的相干现象。     

具有坐标旋转变换的时空相对效应光线跟踪系统

由于基于牛顿经典理论的传统光线跟踪法无法实现物体高速运动时的时空相对效应可视化，本文提出一种改进的光线跟踪系统。通过定义一组参数，使得不同惯性参照系中的坐标系的轴经旋转变换后相互对齐平行．通过建立四维数据结构及加入媒介信息堆栈，可以准确计算光线在媒介中的传输速度及延迟，实现时空系统中光的透射及折射现象的可视化。     

超短激光脉冲中时空耦合效应的研究进展

概述了超短激光脉冲中时空耦合效应的研究进展。将时空耦合效应分为一阶时空耦合和高阶时空耦合两大类,并详细介绍了两类时空耦合效应的研究历史和现状。其中一阶时空耦合效应相对较为简单,对其的理论及实验研究也较为充分。相比一阶时空耦合效应,高阶时空耦合效应的起源更广泛、种类更丰富、时空结构更复杂。目前,对高阶时空耦合效应的研究也刚处于起步阶段。最后,展望了该领域的研究趋势。     

Relativistic Linear Spacetime Transformations Based on Symmetry

Usually the Lorentz transformations are derived from the conservation of the spacetime interval. We propose here a way of obtaining spacetime transformations between two inertial frames directly from symmetry, the isotropy of the space and principle of relativity. The transformation is uniquely defined except for a constant e, that depends only on the process of synchronization of clocks inside each system. Relativistic velocity addition is obtained, and it is shown that the set of velocities is a bounded symmetric domain. If e=0, Galilean transformations are obtained. If e>0, the speed 1/e and a spacetime interval are conserved. By assuming constancy of the speed of light, we get e=1/c ² and the transformation between the frames becomes the Lorentz transformation. If e<0, a proper speed and a Hilbertian norm are conserved.     

Gravitational Wave in Lorentz Violating Gravity

By making use of the weak gravitational field approximation, we obtain a linearized solution of the gravitational vacuum field equation in an anisotropic spacetime. The plane-wave solution and dispersion relation of gravitationaJ wave is presented explicitly. There is possibility that the speed of gravitational wave is larger than the speed of light and the easuality still holds. We show that the energy-momentum of gravitational wave in the ansiotropic spacetime is still well defined and conserved.     

Stability of Cauchy Horizons

We prove that for any 3-dimensional compact hypersurface S in a noncompact 4-dimensional space-time manifold M, S M, the set of Lorentzian metrics on M for which S is a partial Cauchy surface and Cauchy horizon of S is nonempty contains a nonempty open subset (in compact-open topology). This result indicates that the set of metrics admitting Cauchy horizons originating from compact hypersurfaces is large.     

The Principle of Equivalence and the Twin Paradox

No Heading The canonical twin paradox is explained by making a correct use of the principle of equivalence. The role of the principle of equivalence is to provide a physical agent i.e gravity which can supply the required extra aging to the rocket-bound sibling during its acceleration phase through a gravitational time-offset effect. We follow an approach where a novel variation on the twin paradox is used to connect gravity with the desynchronization in the clocks of two spatially distant, identically accelerated observers. It is shown that this approach removes certain drawbacks of an earlier effort which claims to exploit the equivalence principle in explaining the differential aging in the paradox. * Author to whom all correspondences should be made.     

Reply to “nonequivalence of ether theories and special relativity. comment on recent interpretation of Lorentz' Ether theory”

The role played by coordinates in the formulation of an absolute spacetime theory is assessed. It is shown that recent criticism on previous work of ours is wrong.     

Coupled dilaton and electromagnetic field in cylindrically symmetric spacetime

An exact solution is obtained for coupled dilaton and electromagnetic field in a cylindrically symmetric spacetime where an axial magnetic field as well as a radial electric field both are present. Depending on the choice of the arbitrary constants our solution reduces either to dilatonic gravity with pure electric field or to that with pure magnetic field. In the first case we have a curvature singularity at a finite distance from the axis indicating the existence of the boundary of a charged cylinder which may represent the source of the electric field. For the second case we have a singularity on the axis. When the dilaton field is absent the electromagnetic field disappears in both the cases. Whereas the contrary is not true. It is further shown that light rays except for those proceeding in the radial direction are either trapped or escape to infinity depending on the magnitudes of certain constant parameters as well as on the nature of the electromagnetic field. Nature of circular geodesics is also studied in the presence of dilaton field in the cylindrically symmetric spacetime.     

Gravitational Wave in Lorentz Violating Gravity

By making use of the weak gravitational field approximation, we obtain a linearized solution of the gravitational vacuum field equation in an anisotropic spacetime. The plane-wave solution and dispersion relation of gravitational wave is presented explicitly. There is possibility that the speed of gravitational wave is larger than the speed of light and the casuality still holds. We show that the energy-momentum of gravitational wave in the ansiotropic spacetime is still well defined and conserved.     

双生子问题

采用爱因斯坦例子在狭义相对论范畴讨论双生子效应,然后利用直红运动常加速度内禀刚性加速系进一步严格讨论。     

狭义相对论解决双生子佯谬之不可能

详细地阐明了狭义相对论解决双生子佯谬之不可能，对一种很有影响的狭义相对论解进行了深入细致的分析     

A Model for Spacetime II. The Emergence of Higher Dimensions and Field Theory/Strings Dualities

We show that in 4-spacetime modified at very short distances due to the weakening of classical logic, the higher dimensions emerge. We analyse the case of some smooth topoi, and the case of some class of pointless topoi. The pointless topoi raise the dimensionality due to the forcing adding “string” objects and thus replacing classical points in spacetime. Turning to strings would be something fundamental and connected with set theoretical forcing. The field theory/strings dualities originate at the set theoretical level of the theories. It is argued that this fundamental level can help solving some difficulties of the physical dualities.