标题： 非局域弦模型中的弹跳和加速解 显示英文标题

标题： Bouncing and Accelerating Solutions in Nonlocal Stringy Models

摘要： 研究了一类由弦场理论启发的非局部标量场驱动的宇宙学模型。在特定情况下，标量场是弦引力子或弦快子。这些模型的一个显著特征是穿越幽灵分割线。我们揭示了这一现象的本质，表明这是由于初始非局部模型与包含无限多个局部场的模型等价，其中一些场是鬼场。构建了允许精确解的模型变形。这些变形包含锁定势能，以稳定解。给出了反弹和加速解。 显示英文摘要

摘要： A general class of cosmological models driven by a non-local scalar field inspired by string field theories is studied. In particular cases the scalar field is a string dilaton or a string tachyon. A distinguished feature of these models is a crossing of the phantom divide. We reveal the nature of this phenomena showing that it is caused by an equivalence of the initial non-local model to a model with an infinite number of local fields some of which are ghosts. Deformations of the model that admit exact solutions are constructed. These deformations contain locking potentials that stabilize solutions. Bouncing and accelerating solutions are presented.