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The large opacity fluctuations in the $z > 5.5$ Ly$\alpha$ forest mayindicate inhomogeneous progress of reionization. To explain the observed largescatter of the effective Ly$\alpha$ optical depth ($\tau_{\rm eff}$) of theintergalactic medium (IGM), fluctuation of UV background ($\Gamma$ model) orthe IGM gas temperature ($T$ model) have been proposed, which predict oppositecorrelations between $\tau_{\rm eff}$ and galaxy density. In order to addresswhich model can explain the large scatter of $\tau_{\rm eff}$, we search forLy$\alpha$ emitters (LAEs) around two (J1137+3549 and J1602+4228) quasarsightlines with $\tau_{\rm eff}\sim3$ and J1630+4012 sightline with $\tau_{\rmeff}\sim5.5$. Using a narrowband imaging with Subaru/Hyper Suprime-Cam, we drawLAE density maps to explore their spatial distributions. Overdensities arefound within 20 $h^{-1}$Mpc of the quasar sightlines in the low $\tau_{\rmeff}$ regions, while a deficit of LAEs is found in the high $\tau_{\rm eff}$region. Although the $\tau_{\rm eff}$ of the three quasar sightlines areneither high nor low enough to clearly distinguish the two models, theseobserved $\tau_{\rm eff}$-galaxy density relations all consistently support the$\Gamma$ model rather than the $T$ model in the three fields, along with theprevious studies. The observed overdensities near the low $\tau_{\rm eff}$sightlines may suggest that the relic temperature fluctuation does not affectreionization that much. Otherwise, these overdensities could be attributed toother factors besides the reionization process, such as the nature of LAEs aspoor tracers of underlying large-scale structures.

The physical origin for spatially large scatter of IGM opacity at the end of reionization: the IGM Ly$\alpha$ opacity-galaxy density relation