The trace formula of GL(3)

Abstract: Trace formula is an important method to study the Langlands program. In this paper, we will give the explicit coarse trace formula of $\GL(3)$. In general case, Arthur applies the truncation operator on the two sides of trace formula such that they are convergent. In our case, we will prove that the divergent terms of the two sides of the trace formula of $\GL(3)$ are equal. We also obtain the explicit formula for ramified orbits of the geometric side of $\GL(3)$, and show it can be expressed as a limit of distributions of the unramified orbits.