面积度规引力中的引力波信号
Gravitational wave signatures from area metric gravity
AI总结：
该研究探讨源自自旋泡沫等的平移对称线性化面积度规引力理论，分析其类引力波解，推导引力波探测器信号，提出可通过偏振光测量双折射以确定Barbero-Immirzi参数，但相关信号因普朗克质量非长度激发而极弱。
AI中文摘要：
面积度规理论已在多种量子引力方法中被提出作为有效描述：包括有效自旋泡沫的连续极限、弦理论的有效描述以及全息语境下的描述。面积度规作用量允许非拓扑的宇称破缺项，这为通过观测确定Barbero-Immirzi参数提供了可能。我们研究洛伦兹号差下线性化面积度规理论的平移对称版本，该理论尤其源自自旋泡沫和修正Plebanski理论，且避免了引力子扇区的鬼场和快子不稳定性。我们讨论该理论的类引力波解，并通过与电磁耦合的分析，推导引力波探测器中的信号。利用这类干涉仪中的偏振光，原则上可测量面积度规诱导的双折射并确定Barbero-Immirzi参数。然而，假设面积度规中存在普朗克质量的非长度激发，所得信号极其微弱。
英文摘要：
Area metric theories have been proposed as effective descriptions in a number of quantum gravity approaches: as continuum limit of effective spin foams, as an effective description for string theory and in the context of holography. Area metric actions allow for non-topological parity violating terms, which opens the possibility of observationally determining the Barbero-Immirzi parameter. We consider the shift symmetric version of linearized area metric theory in Lorentzian signature, which arises in particular from spin foams and modified Plebanski theory, and avoids ghost and tachyonic instabilities in the graviton sector. We discuss the gravitational wave like solutions of this theory and through an analysis of the coupling to electro-magnetism, deduce the signals in gravitational wave detectors. Using polarized light in such interferometers allows in principle to measure area metric induced birefringence and to determine the Barbero-Immirzi parameter. Assuming Planck massive non-length excitations in the area metric the resulting signal is however extremely weak.
