论文标题
单型式绳子有效描述
A unimodular-like string effective description
论文作者
论文摘要
我们表明，在$ D $ g_ {μν} $中消失的Sigma-Model beta功能，反对称张量$ b_ {μν} $和$ d $ dimentor $ d $ dimensions in Tree水平的任何字符串理论模型的diLaton $φ非动力学。中央电荷赤字术语被从该动作中省略，并在场方程级别上作为集成常数。该分析以$α'$的领先顺序进行，即在有效描述中的两个衍生水平上进行。它可以扩展以结合高阶弦乐校正，Ramond-Ramond形式和模量字段。在所有情况下，非动态场的组合被证明为$ \ sqrt {-g} \，u $，其中$ u $是有效的潜力。当固定某些通量并且模量稳定时，该动作将不会出现宇宙学术语。取而代之的是，宇宙常数将作为一个集成常数，就像在整体相对论的单模型修饰中一样。
We show that vanishing of the sigma-model beta-functions for the metric $g_{μν}$, antisymmetric tensor $B_{μν}$ and dilaton $Φ$ of any string-theory model in $D$ dimensions at tree level can be obtained from a universal effective action, provided that the field combination $\sqrt{-g}e^{-2Φ}$ is non-dynamical. The central-charge deficit term is omitted from the action and appears as an integration constant at the level of the field equations. The analysis is done at leading order in $α'$, i.e. at the two-derivative level in the effective description. It can be extended to incorporate higher order string-loop corrections, Ramond-Ramond forms and moduli fields. In all cases, the non-dynamical field combination turns out to be $\sqrt{-g}\, U$, where $U$ is the effective potential. When certain fluxes are fixed and the moduli fields are stabilized, no cosmological term will arise in the action. Instead, the cosmological constant will appear as an integration constant as in unimodular modifications of general relativity.
