We study the properties of the loosely trapped surface (LTS) and the dynamically transversely trapping surface (DTTS) in Einstein-Maxwell systems. These concepts of surfaces were proposed by the four of the present authors in order to characterize strong gravity regions. We prove the Penrose-like inequalities for the area of LTSs/DTTSs. Interestingly, although the naively expected upper bound for the area is that of the photon sphere of a Reissner-Nordstroem black hole with the same mass and charge, the obtained inequalities include corrections represented by the energy density or pressure/tension of electromagnetic fields. Due to this correction, the Penrose-like inequality for the area of LTSs is tighter than the naively expected one. We also evaluate the correction term numerically in the Majumdar-Papapetrou two-black-hole spacetimes.

中文翻译：

---

爱因斯坦-麦克斯韦系统中的松散俘获面和动态横向俘获面

我们研究了爱因斯坦-麦克斯韦系统中松散俘获表面 (LTS) 和动态横向俘获表面 (DTTS) 的特性。表面的这些概念是由目前的四位作者提出的，以表征强重力区域。我们证明了 LTS/DTTS 区域的 Penrose 式不等式。有趣的是，尽管该区域的天真预期上限是具有相同质量和电荷的 Reissner-Nordstroem 黑洞的光子球的上限，但获得的不等式包括由能量密度或电磁场压力/张力表示的修正。由于这一修正，LTS 区域的 Penrose 式不等式比天真预期的更严格。我们还在 Majumdar-Papapetrou 两个黑洞时空以数值方式评估了校正项。