Cosmology seminar: Claudio Llinares

Cosmological simulations beyond the static approximation

Several extensions of General Relativity and high energy physics include scalar fields as extra degrees of freedom.  In the search for predictions in the non-linear regime of cosmological evolution, the community makes use of numerical simulations in which the quasi-static limit is assumed when solving the equation of motion of the scalar field.  In an effort to assess the reliability of the static approximation, I am developing new algorithms which are being incorporated into a new N-body code that was written from scratch to study modified gravities.  I will present the method, and show results obtained from non-static simulations in the context of the symmetron model.  These simulations show striking differences with respect to the commonly used quasi-static approximation. This novel procedure reveals new physical properties of the scalar field and concealed astrophysical phenomena which were hidden in the old approach.