Enhancement of photon emission rate near QCD critical point

We compute photon emission rate enhancement near the QCD critical point using an effective theory of dynamic critical phenomena and derive a universal photon spectrum. The emission rate scales similarly to conductivity, increasing with the correlation length ($ξ$), diverging at the critical point. The spectrum exhibits $ωdN_γ/d^3k \propto ω^{-1/2}$ in the scaling regime, with the transition occurring at a frequency comparable to shear damping rate $ω\sim γ_η/ξ^2$, reflecting the nonequilibrium properties of the near-critical liquid.