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Orientador(es)
Resumo(s)
The latest cosmological observations by the Planck collaboration (and combined with
others) are compatible with a phantom-like behaviour (w < − 1) for the dark energy equation of state
that drives the current acceleration of the Universe. With this mindset, we look into models where
dark energy is described by a 3-form field minimally coupled to gravity. When compared to a scalar
field, these models have the advantage of more naturally accommodating a cosmological-constant and
phantom-like behaviours. We show how the latter happens for a fairly general class of positive-valued
potentials, and through a dynamical system approach, we find that in such cases the 3-form field
leads the Universe into a Little Sibling of the Big Rip singular event into the future. In this work, we
explore the possibility of avoiding such singularity via an interaction in the dark sector between cold
dark matter and the 3-form field. For the kind of interactions considered, we deduce a condition for
replacing the LSBR by a late time de Sitter phase. For specific examples of interactions that meet this
condition, we look for distinctive imprints in the statefinder hierarchy { S 3 ( 1 ) ; S 4 ( 1 ) } , { S 3 ( 1 ) ; S 5 ( 1 ) } ,
and in the growth rate of matter, e ( z ) , through the composite null diagnostic (CND).
Descrição
Palavras-chave
Dark energy 3-forms DM-DE interaction Dark energy 3-forms Future singularities Cosmography Statefinders approach Growth rate Dynamical systems
Contexto Educativo
Citação
Editora
MDPI