Charge dynamics in an interacting fermionic model on a geometricallyfrustrated lattice are examined. We analyze a spinless fermion model on apaired triangular lattice, an electronic model for layered iron oxides, in zeroand finite temperatures by the exact diagonalization methods. We focus on thetwo charge ordered (CO) phases, termed CO_1/2 and CO_1/3, which, respectively,are realized by the inter-site Coulomb interaction and the quantum/thermalfluctuations. The optical spectra in CO_1/3 show multiple components and theirlow-energy weights are survived even below the ordering temperature (T_CO).Changes of the dynamical charge correlation below T_CO in CO_1/3 are weaklymomentum dependent, in sharply contrast to CO_1/2. These characteristicdynamics in CO_1/3 are attributable to the charge frustration effects, andreproduce some aspects of the recent experimental optical and x-ray scatteringspectra.
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