BBN Constraints on $f(Q,T)$ Gravity
  $f(Q,T)$ gravity is a novel extension of the symmetric teleparallel gravity
where the Lagrangian $L$ is represented through an arbitrary function of the
nonmetricity $Q$ and the trace of the energy-momentum tensor $T$ \cite{fqt}. In
this work, we have constrained a widely used $f(Q,T)$ gravity model of the form
$f(Q,T) = Q^{n+1} + m T$ from the primordial abundances of the light elements
to understand its viability in Cosmology. We report that the $f(Q,T)$ gravity
model can elegantly explain the observed abundances of Helium and Deuterium
while the Lithium problem persists. From the constraint on the expansion factor
in the range $0.9425 \lesssim Z \lesssim1.1525$, we report strict constraints
on the parameters $m$ and $n$ in the range $-1.13 \lesssim n \lesssim -1.08$
and $-5.86 \lesssim m \lesssim12.52$ respectively.
