  We show that liquids and certain holographic models are strikingly similar in
terms of several detailed and specific properties related to their energy
spectra. We consider two different holographic models and ascertain their
similarity with liquids on the basis of emergence of the gap in transverse
momentum space and the functional form of the dispersion relation. Furthermore,
we find that the gap increases with temperature, the relaxation time governing
the gap decreases with temperature and, finally, the gap is inversely
proportional to the relaxation time as in liquids. On this basis, we propose
that Maxwell-Frenkel approach to liquids can be used to understand holographic
models and their strongly-coupled field theory counterparts in a
non-perturbative way.
