2 problems

Let $D:L^2(\widetilde M,\widetilde E)\to L^2(\widetilde M,\widetilde E)$ be a $(\Gamma,\bar\sigma)$-invariant, self-adjoint, elliptic operator on a normal covering space … of a com…

Let $W$ be an algebra over an algebraically closed field $F$ of characteristic zero satisfying a polynomial identity of degree $n$. Suppose that $W$ is nondegenerately graded by a…