2 problems

Let ${*}\text{-}\mathfrak{Alg}$ be the category of non-commutative, associative, $*$-algebras, and let $\mathfrak{Bkgr}_c$ and $\mathfrak{SpBkgr}_c$ be the categories of spacetime…

Let $C^\first$ and $C^{\first}$ be globally hyperbolic spacelike cone bundles over $M$ and $M'$, respectively, and let $\chi\colon M\to M'$ be an embedding inducing a chronological…