论文标题
连接条件和广义耦合理论中的尖锐梯度
Junction conditions and sharp gradients in generalized coupling theories
论文作者
论文摘要
在本文中，我们使用差异方法开发了奇异性高空和连接条件的形式主义。然后，我们利用这种形式主义来检查广义耦合理论中尖锐物质密度梯度的行为。我们发现，这种梯度不一定会导致其他具有辅助场的重力理论中存在的病理。还提供了一个详细的示例，该示例基于称为模型模型的广义耦合理论的简单实例。在静态情况下，我们表明，尽管存在辅助场，但锐利边界并未在动态框架中产生奇异性。取而代之的是，如果具有一般轮廓的球形密度分布崩溃，则额外的力会压缩过度密度并扩大不足。这些结果也可以用于推断该模型参数的其他约束。
In this article, we develop the formalism for singular hypersurfaces and junction conditions in generalized coupling theories using a variational approach. We then employ this formalism to examine the behavior of sharp matter density gradients in generalized coupling theories. We find that such gradients do not necessarily lead to the pathologies present in other theories of gravity with auxiliary fields. A detailed example, based on a simple instance of a generalized coupling theory called the MEMe model, is also provided. In the static case, we show that sharp boundaries do not generate singularities in the dynamical frame despite the presence of an auxiliary field. Instead, in the case of a collapsing spherical density distribution with a general profile an additional force compresses over-densities and expands underdensities. These results can also be used to deduce additional constraints on the parameter of this model.
