Unquenched Effects and Quark Mass Dependence of LatticeGluon Propagator in Infrared Region

In this paper, the gluon propagator in Landau gauge has been studiedon a lattice, including the quenched and the unquenched one. Thesmall geometry size of lattice we use is 16³×32, and thebig one is 20³×64. For the quenched approximation, we fitthe numerical results and give a little different fitting values. We also obtain unquenched effects by comparing the gluon propagator resulting from the quenched and unquenched configurations, for both the two-flavor and three-flavor cases. For the unquenchedconfigurations, an obvious quark mass dependence has not been found inthe small quark mass case, but is found in the three-flavor case when the quark mass is big.