Technion Analysis seminar Speaker: Eyal Subag (Technion) Title: A New Perspective on the Inonu-Wigner Contractions Date: Thursday June 7 at 2:30 p.m. Place: Amado 919. Cookies: 10 minutes before the talk Abstract: Many physical theories approximate other theories under certain limits. Segal, Inonu and Wigner were the first to consider what are the implications of these limits on the corresponding symmetry groups. Contraction is a formal way of applying these limits to Lie groups, Lie algebras and their representations. In recent work we have shown that any contraction of Lie algebra representations is intrinsically a direct limit construction. Moreover, for any Inonu-Wigner contraction of a real three dimensional Lie algebra, we obtained the corresponding contractions of the irreducible representations in a canonical way by pointwise convergence of differential operators. In this talk I'll review contraction of Lie algebras and their representations focusing on the methods of Inonu and Wigner. I will present several examples, some of which are new and show how the direct limit construction arises naturally. This work was done in collaboration with E. M. Baruch, J. L. Birman and A. Mann. Seminar webpage: <http://www.technion.ac.il/%7Etamarzr/analysis.html> --------------------------------------------------------- Technion Math. Net (TECHMATH) Editor: Michael Cwikel <techm@math.technion.ac.il> Announcement from: Tamar Ziegler <tamarzr@tx.technion.ac.il>