A comment on Kerr–CFT and Wald entropy
A comment on Kerr–CFT and Wald entropy
复制标题
DOI：
10.1016/j.physletb.2009.05.056
复制
发表时间：
2009-03
影响因子：
4.4
通讯作者：
C. Krishnan;S. Kuperstein
中科院分区：
文献类型：
--
作者：
C. Krishnan;S. Kuperstein
我们指出，在一般的同胚不变量理论中，使用Kerr-CFT对应和Wald公式（在熵函数形式主义中实现）计算的黑洞熵并不总是一致的。说明这一点的一个简单方法是考虑四维的爱因斯坦-高斯-博内引力，其中高斯-博内项是拓扑的。这意味着在Barnich-Brandt-Compere形式中计算的Kerr-CFT的中心电荷与爱因斯坦引力保持相同，而使用熵函数计算的熵给出了与高斯-邦纳耦合成比例的普适修正。我们认为，至少在这个例子中，Kerr-CFT结果是物理上合理的。解决这一矛盾的办法可能在于更好地理解边界条件。
We point out that the entropies of black holes in general diffeomorphism invariant theories, computed using the Kerr–CFT correspondence and the Wald formula (as implemented in the entropy function formalism), need not always agree. A simple way to illustrate this is to consider Einstein–Gauss–Bonnet gravity in four dimensions, where the Gauss–Bonnet term is topological. This means that the central charge of Kerr–CFT computed in the Barnich–Brandt–Compere formalism remains the same as in Einstein gravity, while the entropy computed using the entropy function gives a universal correction proportional to the Gauss–Bonnet coupling. We argue that at least in this example, the Kerr–CFT result is the physically reasonable one. The resolution to this discrepancy might lie in a better understanding of boundary terms.