标题： 非线性电动力学中黑洞热力学的因果性约束 显示英文标题

标题： Causality Constraints on Black Hole Thermodynamics in Nonlinear Electrodynamics

摘要： 我们研究了非线性电动力学中黑洞热力学的因果性约束，其中拉格朗日量被取为电磁场强度张量的任意函数。通过要求不存在超光速传播，我们证明了极端黑洞的质量与电荷比表现出一种先前在弱引力猜想背景下研究过的单调性。此外，在相同条件下，我们还证明了黑洞的熵与质量平方之比（我们将其解释为熵密度）随着质量的增加而单调递减，同时固定质量与电荷比。这一新的单调性性质将微正则系综中关于黑洞熵的四阶导数修正的正性研究扩展到了非线性电动力学的所有阶次。 显示英文摘要

摘要： We study causality constraints on black hole thermodynamics in nonlinear electrodynamics, where the Lagrangian is taken to be an arbitrary function of the electromagnetic field strength tensor. By requiring the absence of superluminal propagation, we show that the mass-to-charge ratio of extremal black holes exhibits a certain monotonicity previously studied in the context of the weak gravity conjecture. Furthermore, under the same condition, we demonstrate that the entropy-to-mass-squared ratio of black holes, which we interpret as an entropy density, decreases monotonically with increasing mass, while keeping the mass-to-charge ratio fixed. This new monotonicity property extends previous studies on the positivity of four-derivative corrections to black hole entropy in the microcanonical ensemble to all orders in nonlinear electrodynamics.