%0 Journal Article %T $L^p$ spectral theory and heat dynamics of locally symmetric spaces %A Lizhen Ji %A Andreas Weber %J Mathematics %D 2008 %I arXiv %X In this paper we first derive several results concerning the $L^p$ spectrum of arithmetic locally symmetric spaces whose $\Q$-rank equals one. In particular, we show that there is an open subset of $\C$ consisting of eigenvalues of the $L^p$ Laplacian if $p <2$ and that corresponding eigenfunctions are given by certain Eisenstein series. On the other hand, if $p>2$ there is at most a discrete set of real eigenvalues of the $L^p$ Laplacian. These results are used in the second part of this paper in order to show that the dynamics of the $L^p$ heat semigroups for $p<2$ is very different from the dynamics of the $L^p$ heat semigroups if $p\geq 2$. %U http://arxiv.org/abs/0810.0209v2