论文标题
t骨宇宙学:无堕落的自我调整
Tadpole Cosmology: Self Tuning Without Degeneracy
论文作者
论文摘要
退化是一种在标量调节重力模型中适应精确的低能真空状态的方法,尽管存在任意较大的真空能。但是,这种方法需要在拉格朗日中标量场和度量耦合的非常特殊的组合。在这项工作中,我们研究了与限制性的退化条件的不同 - 从包含精确Minkowski空间解决方案的基金模型开始,我们以多种简单的方式打破了退化条件,以测试结果模型是否维持某些关键特征 - 特别是在标量场和低能源真空状态的大型真空能量的动态取消。我们强调了t在消除动力学系统的固定点方面所扮演的角色,从而构成标量场和度量时间依赖性。我们的结果表明,在违反堕落条件但保留了移位对称性时,公制会保持渐近的Minkowski状态,而与宇宙学常数的存在无关。相反,当移位对称性也破裂时,渐近行为会从根本上改变。无论如何,这项工作中的非分类模型具有吸引人的品质。具有独立于真空能量的低能量,迟迟的渐近状态。 t t the t允许比以前实现的更广泛的非分类,自我调整模型。
Degeneracy is a method to accommodate exact, low energy vacuum states in scalar-tensor gravitational models despite the presence of an arbitrarily large vacuum energy. However, this approach requires very particular combinations of scalar field and metric couplings in the Lagrangian. In this work we study departures from the restrictive degeneracy condition -- starting from a fiducial model containing an exact Minkowski space solution, we break the degeneracy condition in numerous simple ways to test if the resulting models maintain certain key features -- specifically the dynamical cancellation of a large vacuum energy by the scalar field and the existence of a low energy vacuum state. We highlight the role the tadpole plays in eliminating the fixed points of the dynamical system, generically rendering both the scalar field and metric time dependent. Our results indicate that when violating the degeneracy condition but preserving shift symmetry, the metric maintains an asymptotic Minkowski state, irrespective of the presence of the cosmological constant. In contrast, when shift symmetry is also broken the asymptotic behaviour can radically alter. Regardless, the non-degenerate models in this work share an attractive quality; harboring low energy, late-time asymptotic states that are independent of the vacuum energy. The tadpole allows for a broader class of non-degenerate, self-tuning models than was previously realized.