Generalized disformal Horndeski theories: consistency of matter coupling and cosmological perturbations

          @misc{ scivideos_PIRSA:24070088,
            doi = {10.48660/24070088},
            url = {https://pirsa.org/24070088},
            author = {Takahashi, Kazufumi},
            keywords = {},
            language = {en},
            title = {Generalized disformal Horndeski theories: consistency of matter coupling and cosmological perturbations},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2024},
            month = {jul},
            note = {PIRSA:24070088 see, \url{https://scivideos.org/pirsa/24070088}}
          }
          

Abstract

Invertible disformal transformations are a useful tool to investigate ghost-free scalar-tensor theories. By performing a higher-derivative generalization of the invertible disformal transformation on Horndeski theories, we construct a novel class of ghost-free scalar-tensor theories, which we dub generalized disformal Horndeski theories. In the talk, I will clarify the basic idea for constructing the invertible disformal transformation with higher derivatives. I will also discuss some aspects of the generalized disformal Horndeski theories, including the consistency of matter coupling and cosmological perturbations.