Fr\'echet completions of moderate growth old and (somewhat) new results

This article has two objectives. The first is to give a guide to the proof of the (so-called) Casselman-Wallach theorem as it appears in Real Reductive Groups II. The emphasis will be on one aspect of the original proof that leads to the new result in this paper which is the second objective. We show how a theorem of van der Noort combined with a clarification of the original argument in my book lead to a theorem with parameters (an alternative is one announced by Berstein and Kr\"otz). This result gives a new proof of the meromorphic continulation of the smooth Eisenstein series

Necessary and sufficient conditions for local manipulation of multipartite pure quantum states

Suppose several parties jointly possess a pure multipartite state, |\psi>. Using local operations on their respective systems and classical communication (i.e. LOCC) it may be possible for the parties to transform deterministically |\psi> into another joint state |\phi>. In the bipartite case, Nielsen majorization theorem gives the necessary and sufficient conditions for this process of entanglement transformation to be possible. In the multipartite case, such a deterministic local transformation is possible only if both the states in the same stochastic LOCC (SLOCC) class. Here we generalize Nielsen majorization theorem to the multipartite case, and find necessary and sufficient conditions for the existence of a local separable transformation between two multipartite states in the same SLOCC class. When such a deterministic conversion is not possible, we find an expression for the maximum probability to convert one state to another by local separable operations. In addition, we find necessary and sufficient conditions for the existence of a separable transformation that converts a multipartite pure state into one of a set of possible final states all in the same SLOCC class. Our results are expressed in terms of (1) the stabilizer group of the state representing the SLOCC orbit, and (2) the associate density matrices (ADMs) of the two multipartite states. The ADMs play a similar role to that of the reduced density matrices, when considering local transformations that involves pure bipartite states. We show in particular that the requirement that one ADM majorize another is a necessary condition but in general far from being also sufficient as it happens in the bipartite case.Comment: Published version. Abstract and introduction revised significantl