标题： 任意耦合标量电荷在圆柱形薄壳时空中的自力 显示英文标题

标题： Self-force on an arbitrarily coupled scalar charge in cylindrical thin-shell spacetimes

摘要： 我们考虑在具有一个或两个渐近区域的圆柱形时空中，静态无质量标量电荷的任意耦合场和自力，其中唯一的物质内容集中在由外曲率跳跃的迹 $\kappa$表征的薄壳中。 自力在曲率耦合 $\xi$的基础上进行数值和分析研究。 我们找到了临界值 $\xi_c^{(n)} = n/ ( \rho(r_s)\,\kappa )$，其中 $n \in \mathbb{N}$和 $\rho(r_s)$是壳层位置度规的轮廓函数，在背景配置中标量场是发散的。 通过将耦合限制在稳定域中，可以消除这种病态行为。 耦合对壳附近自力有显著影响，我们确定$\xi=1/4$为标量力在$r_s$邻域变号的值；如果$\kappa (1-4\xi)>0$壳作为有效势垒产生排斥作用，而如果$\kappa (1-4\xi)<0$则作为势阱吸引电荷。 渐近自力的符号仅取决于电荷所在外部区域是否存在角度缺陷；圆锥渐近产生主要的吸引力，而闵可夫斯基区域产生排斥的渐近自力。 显示英文摘要

摘要： We consider the arbitrarily coupled field and self-force of a static massless scalar charge in cylindrical spacetimes with one or two asymptotic regions, with the only matter content concentrated in a thin-shell characterized by the trace of the extrinsic curvature jump $\kappa$. The self-force is studied numerically and analytically in terms of the curvature coupling $\xi$. We found the critical values $\xi_c^{(n)} = n/ ( \rho(r_s)\,\kappa )$, with $n \in \mathbb{N}$ and $\rho(r_s)$ the metric's profile function at the position of the shell, for which the scalar field is divergent in the background configuration. The pathological behavior is removed by restricting the coupling to a domain of stability. The coupling has a significant influence over the self-force at the vicinities of the shell, and we identified $\xi=1/4$ as the value for which the scalar force changes sign at a neighborhood of $r_s$; if $\kappa (1-4\xi)>0$ the shell acts repulsively as an effective potential barrier, while if $\kappa (1-4\xi)<0$ it attracts the charge as a potential well. The sign of the asymptotic self-force only depends on whether there is an angle deficit or not on the external region where the charge is placed; conical asymptotics produce a leading attractive force, while Minkowski regions produce a repulsive asymptotic self-force.