Cosmological dynamics of multifield dark energy
Cosmological dynamics of multifield dark energy
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DOI：
10.1103/physrevd.106.023512
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发表时间：
2022-01
影响因子：
5
通讯作者：
J. R. Eskilt;Yashar Akrami;A. Solomon;V. Vardanyan
中科院分区：
文献类型：
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作者：
J. R. Eskilt;Yashar Akrami;A. Solomon;V. Vardanyan
我们用数值和分析方法探索了具有高度非测地线或“旋转”场空间轨迹的多场暗能量的背景宇宙学动力学。这些标准单场精萃的扩展具有吸引人的理论特征和与宇宙学标准模型的可观察到的差异。在宇宙背景的水平上，我们进行了相空间分析，并在广泛的初始条件下确定了具有晚时加速度的近似吸引子。关注两类场空间几何，我们通过要求可行的晚时加速和梯度不稳定性的缺失，以及从de Sitter沼泽猜想中推导出参数空间的界。
We numerically and analytically explore the background cosmological dynamics of multifield dark energy with highly nongeodesic or “spinning” field-space trajectories. These extensions of standard single-field quintessence possess appealing theoretical features and observable differences from the cosmological standard model. At the level of the cosmological background, we perform a phase-space analysis and identify approximate attractors with late-time acceleration for a wide range of initial conditions. Focusing on two classes of field-space geometry, we derive bounds on parameter space by demanding viable late-time acceleration and the absence of gradient instabilities, as well as from the de Sitter swampland conjecture.