论文标题
在各种重力理论中寻找动态黑洞
Searching for dynamical black holes in various theories of gravity
论文作者
论文摘要
我们构建了爱因斯坦和$ f（r）$重力的模型，其中有两个标量场，该模型允许分析解决方案描述了时间变化的动态黑洞。它们的热力学在绝热近似中进行了研究。除了misner-sharp-hernandez准局部质量外，我们还提供时间依赖的热力学量，包括鹰温度，Helmholtz自由能，熵和热力学能量。后者并不总是与地平线上的Misner-Sharp-Hernandez质量相吻合，尽管它们在静态极限上重合。对于Schwarzschild-type（即，$ g_ {tt} g_ {rr} = - 1 $ 1 $）在爱因斯坦重力中，两个标量之一始终是一个具有负动能的幽灵。我们表明，可以在$ f（r）$重力中避免这种幽灵。
We construct models of Einstein and $f(R)$ gravity with two scalar fields, which admit analytical solutions describing time-varying dynamical black holes. Their thermodynamics is investigated in the adiabatic approximation. In addition to the Misner-Sharp-Hernandez quasilocal mass, we provide time-dependent thermodynamical quantities, including the Hawking temperature, Helmholtz free energy, entropy, and thermodynamical energy. The latter does not always coincide with the Misner-Sharp-Hernandez mass at the horizon, although they coincide in the static limit. For Schwarzschild-type (i.e., $g_{tt}g_{rr}=-1$) black holes in Einstein gravity, one of the two scalars is always a ghost with negative kinetic energy. We show that this ghost can be avoided in $f(R)$ gravity.
