2017-04-24

UTAPwiki/セミナー/初期宇宙・相対論速報
Speaker: Kazufumi Takahashi (RESCEU)
Title: Field transformation and mimetic gravity
Abstract:
In our recent paper arXiv:1702.01849, we proved that the number of physical degrees of freedom (DOFs) is not changed by an invertible field transformation.
On the other hand, this is not the case if the field transformation is not invertible.
In the context of scalar-tensor theories, the so-called mimetic gravity model is obtained by a noninvertible conformal transformation of the Einstein-Hilbert action, which introduces an extra scalar DOF.
In this talk, I will summarize the results of arXiv:1702.01849 on invertible transformations, and then mention mimetic gravity as an example of a theory resulting from a noninvertible transformation.