  The deconfined quantum critical point of a two-dimensional SU(N)
antiferromagnet is governed by an Abelian Higgs model in $d=2+1$ spacetime
dimensions featuring $N$ complex scalar fields. In this context, we derive for
$2\leq d\leq 4$ an exact formula for the central charge of the U(1) current in
terms of the gauge coupling at quantum criticality and compare it with the
corresponding result obtained using gauge-gravity duality. There is a
remarkable similarity precisely for $d=2+1$. In this case the amplitude of the
current correlation function has the same form as predicted by the
gauge-gravity duality. We also compare finite temperature results for the
charge susceptibility in the large $N$ limit with the result predicted by the
gauge-gravity duality. Our results suggest that condensed matter systems at
quantum criticality may provide interesting quantitative tests of the
gauge-gravity duality even in absence of supersymmetry.
