近日，印度塔塔基础研究所Singhi, Kaustubh团队研究了复杂的Kerr-AdS黑洞。这一研究成果发表在2026年2月12日出版的《高能物理杂志》上。

研究组运用欧几里得路径积分重新审视了有限温度与转动下五维AdS时空的热力学性质。普遍认为，在低温且有限转动条件下，主导热力学体统的体鞍点描述的是热辐射旋转气体，相应的低温对偶规范理论处于禁闭热态。

研究组证明这一全息预期与以下事实相悖：即使在低温区域，仍存在在壳作用量实部小于热旋转气体的体路径积分鞍点。具有复参数的常规Kerr-AdS黑洞便是此类鞍点的范例。借助微超空间思想与最速下降法，研究组论证这些额外鞍点实际上并不贡献低温配分函数，从而挽救了“旋转热气体确为理解低温对偶规范理论的正确背景”这一原始论断。作为推论，研究组还发现不稳定的小型旋转黑洞在任何温度下均不贡献配分函数，即使以抑制形式亦不存在。

附：英文原文

Title: Complex Kerr-AdS black holes

Author: Singhi, Kaustubh

Issue&Volume: 2026-02-12

Abstract: We revisit thermodynamics of five-dimensional AdS spacetime at finite temperature and rotation using the Euclidean path integral. It is generally believed that at low temperatures and finite rotation, the bulk saddle point that governs the thermodynamics describes a rotating gas of thermal radiation. Consequently, the dual gauge theory at low temperatures is in a confined thermal state. We demonstrate that this holographic expectation is at odds with the fact that, even at low temperatures, there exist saddles of the bulk path integral with real part of on-shell action smaller than that of the thermal rotating gas. The usual Kerr-AdS black holes but with complex parameters are examples of such saddles. Using mini-superspace ideas and steepest descent, we argue that these additional saddles do not actually feature in the low temperature partition function. This saves the original claim that rotating thermal gas is indeed the correct background for understanding the dual gauge theory at low temperatures. As a corollary, we also find that the unstable small rotating black hole does not contribute to the partition function at any temperature, even in a suppressed manner.

DOI: 10.1007/JHEP02(2026)138

Source: https://link.springer.com/article/10.1007/JHEP02(2026)138