标题： ADM 在双度规变分形式主义框架下对引力模型的分析 显示英文标题

标题： ADM Analysis of Gravity Models within the Framework of Bimetric Variational Formalism

摘要： 双度规变分形式最近被用来构建新的双度规引力模型。在这些模型中，仿射联络由一个独立于物理度规的额外张量场生成。在这项工作中，我们演示了如何应用ADM分解来研究这类模型，并提供了一些技术性的中间细节。利用ADM分解，我们能够证明一个线性模型是不稳定的，这与之前摄动分析的结果一致。此外，我们还表明，在双度规变分形式框架内构造一个无鬼的非线性模型是非常困难甚至不可能的。然而，我们证明了沿类似思路是可以得到可行的模型的。为此，我们考虑了一种设定，其中仿射联络是黎曼联络的变化。作为原理的证明，我们构建了一个通过这种方式获得的带有无质量标量场的引力模型。 显示英文摘要

摘要： Bimetric variational formalism was recently employed to construct novel bimetric gravity models. In these models an affine connection is generated by an additional tensor field which is independent of the physical metric. In this work we demonstrate how the ADM decomposition can be applied to study such models and provide some technical intermediate details. Using ADM decomposition we are able to prove that a linear model is unstable as has previously been indicated by perturbative analysis. Moreover, we show that it is also very difficult if not impossible to construct a non-linear model which is ghost-free within the framework of bimetric variational formalism. However, we demonstrate that viable models are possible along similar lines of thought. To this end, we consider a set up in which the affine connection is a variation of the Levi-Civita one. As a proof of principle we construct a gravity model with a massless scalar field obtained this way.