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M.Braglia:Ho tension and non-minimal coupling to gravity

New postPosted: Tue 30 Jun 2020 14:53
by Maxim Khlopov
Seminar by Matteo Braglia "The H0 tension and non-minimal couplings to gravity" was given on 30.06.2020. His presentation is attached and the record
will appear soon.
The following questions and comments were put
Julié: Could you recall the difference between your work and that of Solà et al? What did you mean by 'ghost'?
Julié: but all these theories (BD) are subclasses of DHOST, so how can there be ghosts?
O.M. Lecian: what constraints are found in vacuum with the ghost case in the two frames?
Julié: I think DHOST theories are devoid of ghosts by construction
Holger: Are this kind of modified gravity involving very large couplings and how large compared to dimensional expectations?
Chiara Caprini: is there any particular physical motivation to add N_eff to conformal coupling or JBD models? do they offer some candidate for a non trivial N_eff?
O.M. Lecian: how are all the ghosts field eliminated, as from the presence of the box operator
of the $phi$ field?
Julié: Is your work encompassing BD theories with cosmological attractors towards GR (à la Damour-Nordtvedt)?
O.M. Lecian: You are meaning that the \sigma^2 is completely eliminating the ghosts?

O.M. Lecian:

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