Dark energy condensation
Dark energy condensation
复制标题
暗能量凝结
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
M. Pietroni
中科院分区：
文献类型：
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作者：
M. Pietroni
暗能量的两个最受欢迎的候选者，即宇宙常数和精髓，在观测上很难区分，主要是因为精髓场没有相当大的波动。我们研究了暗能量标量场模型，其中标量场在反射对称性 {phi}{yields}-{phi} 下保持不变。在一般假设下，后期会发生相变（z < 或约 0.5）。在相变之前，场表现为宇宙常数。相变后，形成与时间相关的 {phi}-凝聚体，场与暗物质耦合并产生跟踪暗物质的相当大的扰动。背景宇宙学演化与现有观测结果一致，但未来的超新星巡天可能会与宇宙学常数的演化清楚地区分开来。宇宙扰动的增长带有相变的印记，但是必须开发非线性方法才能对其进行定量研究。
The two most popular candidates for dark energy, i.e. a cosmological constant and quintessence, are very difficult to distinguish observationally, mostly because the quintessence field does not have sizable fluctuations. We study a scalar field model for dark energy in which the scalar field is invariant under reflection symmetry {phi}{yields}-{phi}. Under general assumptions, there is a phase transition at late times (z < or approx. 0.5). Before the phase transition, the field behaves as a cosmological constant. After the phase transition, a time-dependent {phi}-condensate forms, the field couples with dark matter and develops sizable perturbations tracking those of dark matter. The background cosmological evolution is in agreement with existing observations, but might be clearly distinguished from that of a cosmological constant by future Supernovae surveys. The growth of cosmological perturbations carries the imprint of the phase transition, however a nonlinear approach has to be developed in order to study it quantitatively.