INSTITUTO DE INVESTIGACIONES FISICAS DE MAR DEL PLATA
Unidad Ejecutora - UE
Primordial magnetic fields from a non-singular bouncing cosmology
FEDERICO AGUSTIN, MEMBIELA
NUCLEAR PHYSICS B
ELSEVIER SCIENCE BV
Lugar: Amsterdam; Año: 2014 vol. 885 p. 196 - 196
Although inflation is a natural candidate to generate the lengths of coherence of magnetic fields needed to explain current observations, it needs to break conformal invariance of electromagnetism to obtain significant magnetic amplitudes. Of the simplest realizations are the kinetically-coupled theories f^2(ϕ)FμνFμν (or IFF theories). However, these are known to suffer from electric fields backreaction or the strong coupling problem. In this work we shall confirm that such class of theories are problematic to support magnetogenesis during inflationary cosmology. On the contrary, we show that a bouncing cosmology with a contracting phase dominated by an equation of state with p>−ρ/3 can support magnetogenesis, evading the backreaction/strong-coupling problem. Finally, we study safe magnetogenesis in a particular bouncing model with an ekpyrotic-like contracting phase. In this case we found that f^2(ϕ)F^2-instabilities might arise during the final kinetic-driven expanding phase for steep ekpyrotic potentials.