Refining the classification of the irreps of the 1D N-Extended Supersymmetry

The linear finite irreducible representations of the algebra of the 1D $N$-Extended Supersymmetric Quantum Mechanics are discussed in terms of their "connectivity" (a symbol encoding information on the graphs associated to the irreps). The classification of the irreducible representations with the same fields content and different connectivity is presented up to $N\leq 8$.Comment: Two extra cases added. Reply to hep-th/0611060v2 comments adde

Decomposition and Oxidation of the N-Extended Supersymmetric Quantum Mechanics Multiplets

We furnish an algebraic understanding of the inequivalent connectivities (computed up to $N\leq 10$) of the graphs associated to the irreducible supermultiplets of the N-extended Supersymmetric Quantum Mechanics. We prove that the inequivalent connectivities of the N=5 and N=9 irreducible supermultiplets are due to inequivalent decompositions into two sets of N=4 (respectively, N=8) supermultiplets. "Oxido-reduction" diagrams linking the irreducible supermultiplets of the N=5,6,7,8 supersymmetries are presented. We briefly discuss these results and their possible applications.Comment: 15 pages, 5 figure

A duality of locally compact groups which does not involve the Haar measure

We present a simple and intuitive framework for duality of locally compacts groups, which is not based on the Haar measure. This is a map, functorial on a non-degenerate subcategory, on the category of coinvolutive Hopf \cst-algebras, and a similar map on the category of coinvolutive Hopf-von Neumann algebras. In the \cst-version, this functor sends $C_0(G)$ to $C^*(G)$ and vice versa, for every locally compact group $G$. As opposed to preceding approaches, there is an explicit description of commutative and co-commutative algebras in the range of this map (without assumption of being isomorphic to their bidual): these algebras have the form $C_0(G)$ or $C^*(G)$ respectively, where $G$ is a locally compact group. The von Neumann version of the functor puts into duality, in the group case, the enveloping von Neumann algebras of the algebras above: $C_0(G)^{**}$ and $C^*(G)^{**}$.Comment: To appear in Math. Scan

An example of a weighted algebra Lpw(G)L_p^w(G) on uncountable group

We construct examples of weighted algebras $L_p^w(G)$ with $1<p\le 2$ on uncountable free groups. For $p>2$ no weighted algebras exist on these groups. From the other side, we prove that an amenable group on which exist weighted algebras with $p>1$ must be sigma-compact

On continuity of measurable group representations and homomorphisms

Let G be a locally compact group, and let U be its unitary representation on a Hilbert space H. Endow the space L(H) of linear bounded operators on H with weak operator topology. We prove that if U is a measurable map from G to L(H) then it is continuous. This result was known before for separable H. To prove this, we generalize a known theorem on nonmeasuralbe unions of point finite families of null sets. We prove also that the following statement is consistent with ZFC: every measurable homomorphism from a locally compact group into any topological group is continuous. This relies, in turn, on the following theorem: it is consistent with ZFC that for every null set S in a locally compact group there is a set A such that AS is non-measurable.Comment: The previous version was not final, I update it once notice