论文标题
$α'$ - 宇宙学及其无张力极限的完整理论
An $α'$-complete theory of cosmology and its tensionless limit
论文作者
论文摘要
我们探讨了由于Hohm，Siegel和Zwiebach（HSZ），专门针对宇宙学背景而导致双场理论的二元性不变性扩展。尽管在其原始配方中具有有限数量的衍生物，但该理论还是针对公制，B场和Dilaton进行了无限的许多$α'$校正，这些校正是在整合了某些额外的领域后获得的。我们仅根据时间的不同而进行宇宙学的减少，并显示出这种截断的一致性。我们计算一般宇宙学分类的$α'^4 $系数。作为如何处理字符串理论中所有$α'校正的可能模型，我们给出了保留额外领域的两衍生重新构造。然后，相应的弗里德曼方程是捕获所有$α'$校正的普通二阶微分方程。我们探讨了无张力的限制$α'\ rightarrow \ infty $，该$具有Sitter de Sitter vacua，我们以$ \ frac {1} {α'} $设置了扰动理论。
We explore the exactly duality invariant higher-derivative extension of double field theory due to Hohm, Siegel and Zwiebach (HSZ) specialized to cosmological backgrounds. Despite featuring a finite number of derivatives in its original formulation, this theory encodes infinitely many $α'$ corrections for metric, B-field and dilaton, which are obtained upon integrating out certain extra fields. We perform a cosmological reduction with fields depending only on time and show consistency of this truncation. We compute the $α'^4$ coefficients of the general cosmological classification. As a possible model for how to deal with all $α'$ corrections in string theory we give a two-derivative reformulation in which the extra fields are kept. The corresponding Friedmann equations are then ordinary second order differential equations that capture all $α'$ corrections. We explore the tensionless limit $α'\rightarrow \infty$, which features string frame de Sitter vacua, and we set up perturbation theory in $\frac{1}{α'}$.
