Antipodally symmetric gauge fields and higher-spin gravity in de Sitter space

We study gauge fields of arbitrary spin in de Sitter space. These include Yang-Mills fields and gravitons, as well as the higher-spin fields of Vasiliev theory. We focus on antipodally symmetric solutions to the field equations, i.e. ones that live on "elliptic" de Sitter space dS_4/Z_2. For free fields, we find spanning sets of such solutions, including boundary-to-bulk propagators. We find that free solutions on dS_4/Z_2 can only have one of the two types of boundary data at infinity, meaning that the boundary 2-point functions vanish. In Vasiliev theory, this property persists order by order in the interaction, i.e. the boundary n-point functions in dS_4/Z_2 all vanish. This implies that a higher-spin dS/CFT based on the Lorentzian dS_4/Z_2 action is empty. For more general interacting theories, such as ordinary gravity and Yang-Mills, we can use the free-field result to define a well-posed perturbative initial value problem in dS_4/Z_2.
Comment: 37 pages; v3: major rewrite - added boundary-to-bulk propagators, concluded that all higher-spin n-point functions in dS/Z_2 are singular, retracted the CFT model accordingly; v4: JHEP version, slightly expanded presentation; v5: corrected some propagator normalizations; v6: standardized normalization conventions between papers; v7: further correction to propagator normalizations