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arXiv 0902.2790hep-th
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CFT与量子引力的一个普适不等式

A Universal Inequality for CFT and Quantum Gravity

Simeon Hellerman

AI总结:

本文利用幺正性与模不变性证明二维CFT必存在轻初级算符,并通过AdS_3/CFT_2对偶给出三维量子引力中有质量激发的普适质量上界。

摘要:

我们证明,每个幺正的二维共形场论(不含扩展手征代数,且中心荷 $c_L, c_R > 1$)都包含一个维数为 $Δ_1$ 的初级算符,其满足 $0 < Δ_1 < (c_L + c_R)/12 + 0.473695$。利用 AdS_3/CFT_2 词典将其转换为引力语言后,我们的结果严格证明,在任何宇宙学常数 $Λ<0$ 的三维引力理论中,最轻的有质量激发都不可能重于 $1/(4 G_N) + o(|Λ|^(1/2))$。在平直空间近似下,这一极限质量是最轻 BTZ 黑洞质量的两倍。该界的推导适用于 CFT 的有限中心荷,并不依赖大中心荷下的渐近展开。我们的证明也不依赖 CFT 的任何特殊性质,例如超对称或全纯分解,也不依赖基于弦论或半经典引力的任何体解释。我们唯一的假设是对偶 CFT 的幺正性和模不变性。我们的证明首次表明,存在一个普适的质心能量,超过该能量后,“纯”量子引力理论永远无法被一致地扩展。

英文摘要:

We prove that every unitary two-dimensional conformal field theory (with no extended chiral algebra, and with central charges $c_L, c_R > 1$) contains a primary operator with dimension $Δ_1$ that satisfies $0 < Δ_1 < (c_L + c_R)/12 + 0.473695$. Translated into gravitational language using the AdS_3 /CFT_2 dictionary, our result proves rigorously that the lightest massive excitation in any theory of 3D gravity with cosmological constant $Λ< 0$ can be no heavier than $1/(4 G_N) + o(|Λ|^(1/2))$. In the flat-space approximation, this limiting mass is twice that of the lightest BTZ black hole. The derivation of the bound applies at finite central charge for the CFT, and does not rely on an asymptotic expansion at large central charge. Neither does our proof rely on any special property of the CFT such as supersymmetry or holomorphic factorization, nor on any bulk interpretation in terms of string theory or semiclassical gravity. Our only assumptions are unitarity and modular invariance of the dual CFT. Our proof demonstrates for the first time that there exists a universal center-of-mass energy beyond which a theory of "pure" quantum gravity can never consistently be extended.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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