We present a thorough analysis of the electromagnetic response of strongly
coupled neutral plasmas described by the gauge/gravity correspondence. The
coupling of the external electromagnetic field with the tower of quasi-normal
modes of the plasmas supports the presence of various electromagnetic modes
with different properties. Among them we underline the existence of negative
refraction with low dissipation for a transverse non-hydrodynamical mode.
Previous hydrodynamical approaches have shown the ubiquitous character of
negative refraction in charged plasmas and the absence thereof in neutral
plasmas. Our results here extend the analysis for neutral plasmas beyond the
hydrodynamical regime. As an application of these new insights we briefly
discuss the case of the quark gluon plasma in the temperature dominated regime.Comment: 29 pages, 15 figure