Time-like geodesic structure for the K-essence Emergent Barriola-Vilenkin type spacetime

通过$k$-essence研究Barriola-Vilenkin时空的零测地线结构

Null geodesic structure for the Barriola-Vilenkin spacetime via $k$-essence

本文在k-essence理论中研究涌现Barriola-Vilenkin时空的零测地线结构，揭示恒定暗能量密度导致其轨迹偏离典型Schwarzschild时空。

为何巴里奥拉-维伦金全球单极不能旋转？

Why Barriola--Vilenkin Global Monopoles Cannot Rotate?

本文研究了巴里奥拉-维伦金全球单极能否作为爱因斯坦-标量场方程的解，证明了通过新曼-詹尼斯算法生成的静态单极度规与标量场运动方程不一致，且仅静态球对称解在远距离处是规则的，从而得出结论：巴里奥拉-维伦金全球单极在爱因斯坦广义相对论框架下无法与旋转时空兼容。

Hawking temperature for a global monopole metric in the context of k- essence and emergent gravity

The Hawking temperature for the Barriola-Vilenkin global monopole metric is shown to be $T_{\mathrm BV}= {\hbar (1-α) ^{2}\over8πGM k_{\mathrm B}}$, where $α$ is the global monopole charge,$M$ the mass of the black hole, $k_{\mathrm B}$ is the Boltzmann constant and speed of light $c=1$. We then show that a similar metric can also be obtained for certain $k-$ essence field configurations in an emergent gravity situation. Therefore, in the context of Belgiorno {\it et al's} recent demonstration of spontaneous emission of photons in a gravitational analogue experiment, any future observation of …

On the exact gravitational lens equation in spherically symmetric and static spacetimes

Lensing in a spherically symmetric and static spacetime is considered, based on the lightlike geodesic equation without approximations. After fixing two radius values r_O and r_S, lensing for an observation event somewhere at r_O and static light sources distributed at r_S is coded in a lens equation that is explicitly given in terms of integrals over the metric coefficients. The lens equation relates two angle variables and can be easily plotted if the metric coefficients have been specified; this allows to visualize in a convenient way all relevant lensing properties, giving image positions,…

The local and global geometrical aspects of the twin paradox in static spacetimes: II. Reissner--Nordström and ultrastatic metrics

This is a consecutive paper on the timelike geodesic structure of static spherically symmetric spacetimes. First we show that for a stable circular orbit (if it exists) in any of these spacetimes all the infinitesimally close to it timelike geodesics constructed with the aid of the general geodesic deviation vector have the same length between a pair of conjugate points. In Reissner--Nordström black hole metric we explicitly find the Jacobi fields on the radial geodesics and show that they are locally (and globally) maximal curves between any pair of their points outside the outer horizon. If …