  The pairing of two electrons on a Fermi surface due to an infinitesimal
attraction between them always results in a superconducting instability at zero
temperature ($T=0$). The equivalent question of pairing instability on a
Luttinger surface (LS) -- a contour of zeros of the propagator -- instead leads
to a quantum critical point (QCP) that separates a non-Fermi liquid (NFL) and
superconductor. A surprising and little understood aspect of pair fluctuations
at this QCP is that their thermodynamics maps to that of the Sachdev-Ye-Kitaev
(SYK) model in the strong coupling limit. Here, we offer a simple justification
for this mapping by demonstrating that (i) LS models share the
reparametrization symmetry of the $q\rightarrow \infty$ SYK model with $q$-body
interactions \textcolor{black}{close to the LS}, and (ii) the enforcement of
gauge invariance results in a $\frac{1}{\sqrt{\tau}}$ ($\tau\sim T^{-1}$)
behavior of the fluctuation propagator near the QCP, as is a feature of the
fundamental SYK fermion.
