论文标题
均等违反标量非对称理论的两极分化引力波
Polarized gravitational waves in the parity violating scalar-nonmetricity theory
论文作者
论文摘要
在研究重力理论和宇宙学量表中可能违反平均特征的可能性违反特征的可能性越来越多。在这项工作中，我们考虑了一类标量非对称理论，其中拉格朗日是由非赞誉张量和标量场构建的多项式。非赞誉张量与标量场通过其一阶导数耦合。除了在非赞誉张量中是二次顺序的单一序列外，我们还构建了单一元素，这些单元在非赞成体张量中是在保留和违反案例中的非对象张量中的立方顺序。这些单元充当时空度量标准的非传统（即非二次）动力学项，并将改变引力波传播的行为。我们发现，引力波通常是极化的，由于违反了该理论，这既具有振幅和速度双重特征。由于相位速度的术语与$ 1/k $成正比，因此两种极化模式之一遭受了梯度不稳定性。
There has been increasing interest in investigating the possible parity violating features in the gravity theory and on the cosmological scales. In this work, we consider a class of scalar-nonmetricity theory, of which the Lagrangian is polynomial built of the nonmetricity tensor and a scalar field. The nonmetricity tensor is coupled with the scalar field through its first order derivative. Besides the monomials that are quadratic order in the nonmetricity tensor, we also construct monomials that are cubic order in the nonmetricity tensor in both the parity preserving and violating cases. These monomials act as the non-canonical (i.e., non-quadratic) kinetic terms for the spacetime metric, and will change the behavior in the propagation of the gravitational waves. We find that the gravitational waves are generally polarized, which present both the amplitude and velocity birefringence features due to the parity violation of the theory. Due to the term proportional to $1/k$ in the phase velocities, one of the two polarization modes suffers from the gradient instability on large scales.
