黑洞熵公式的简单推导

　Black hole is treated as 2-D membrane. Starting from the usual state equation of thermal radiation, the black hole entropy is technically computed, and the result that is proportional to the area of horizon is briefly obtained.     

Horizon-less Spherically Symmetric Vacuum-Solutions in a Higgs Scalar-Tensor Theory of Gravity

The exact static and spherically symmetric solutions of the vacuum field equations for a Higgs Scalar-Tensor theory (HSTT) are derived in Schwarzschild coordinates. It is shown that in general there exists no Schwarzschild horizon and that the fields are only singular (as naked singularity) at the center (i.e. for the case of a point-particle). However, the Schwarzschild solution as in usual general relativity (GR) is obtained for the vanishing limit of Higgs field excitations.     

Gain–loss asymmetry for emerging stock markets

Stock indexes for some European emerging markets are analyzed using an investment-horizon approach. Austrian ATX index and Dow Jones have been studied and compared with several emerging European markets. The optimal investment horizons are plotted as a function of an absolute return value. Gain–loss asymmetry, originally found for American DJIA index, is observed for all analyzed data. It is shown, that this asymmetry has different character for emerging and for established markets. For established markets, gain curve lies typically above loss curve, whereas in the case of emerging markets the situation is just the opposite. We propose a measure quantifying the gain–loss asymmetry that clearly exhibits a difference between emerging and established markets.     

黑洞的高温喷流

从零曲面方程出发得出，匀加速直线运动的动态黑洞时空存在２个事件视界－黑洞视界和它的Ｒｉｎｄｌｅｒ视界。发现２个视界相接触时，接触点处的Ｈｗａｋｉｎｇ温度都降为零。而在黑洞视界的另一相反极点处的Ｈａｗｋｉｎｇ温度将迅速升高，并形成高温喷流。     

变加速带电黑洞热效应的讨论

给出了变加速直线运动带电黑洞的ＨＭ效应和事件视界以及相应的温度．发现带电黑洞的Ｈａｗｋｉｎｇ温度不仅依赖于时间，而且依赖于极角．利用Ｙｏｒｋ的方法讨论事件视界和Ｋｌｅｉｎ－Ｇｏｒｄｏｎ方程，结果得到进一步约化，物理意义也更为明显．     

The dynamics of asset lifetime under technological change

The variable lifetime of assets is analyzed in a serial replacement problem. Technological change impacts the maintenance cost and new asset cost. The optimal asset lifetime appears to be constant only when both costs decrease with the same rate. We identify cases when the technological change decreases or increases the optimal lifetime.     

Backward Stochastic Riccati Equations and Infinite Horizon L-Q Optimal Control with Infinite Dimensional State Space and Random Coefficients

We study the Riccati equation arising in a class of quadratic optimal control problems with infinite dimensional stochastic differential state equation and infinite horizon cost functional. We allow the coefficients, both in the state equation and in the cost, to be random. In such a context backward stochastic Riccati equations are backward stochastic differential equations in the whole positive real axis that involve quadratic non-linearities and take values in a non-Hilbertian space. We prove existence of a minimal non-negative solution and, under additional assumptions, its uniqueness. We show that such a solution allows to perform the synthesis of the optimal control and investigate its attractivity properties. Finally the case where the coefficients are stationary is addressed and an example concerning a controlled wave equation in random media is proposed.     

匀加速直线运动动态黑洞的3类特征曲面

讨论了匀加速直线运动态黑洞的３种特征曲面－事件视界，表观视界和类时极限面的一些性质。     

电磁直线加速黑洞的视界特征

研究了带有电磁荷的直线加速黑洞的视界几何特征，利用广义动量算子得到黑洞的视界面方程，尝试地使用分离法初步找到视界的基本几何特征。     

考察Kerr-Newman黑洞事件视界的稳定性

建立了一个假想实验来考察Kerr－Newman黑洞事件视界的稳定性．作者试图靠掉入试验粒子来增加黑洞的角动量和电量，从而破坏黑洞的极限条件．但是无论试验粒子出发点离黑洞远近怎样，任何破坏黑洞事件视界稳定性的过程都被禁止Kerr－Newman黑洞的事件视界是稳定的．