ar X iv : 0 80 1 . 08 75 v 2 [ m at h . D S ] 2 6 Ja n 20 08 GROUPS NOT ACTING ON MANIFOLDS

ar X iv : 0 80 1 . 25 00 v 1 [ co nd - m at . o th er ] 1 6 Ja n 20 08 Making , probing and understanding ultracold Fermi

ar X iv : 0 80 1 . 36 64 v 1 [ co nd - m at . m tr l - sc i ] 2 3 Ja n 20 08 Universality behind Basquin ’ s law of fatigue

F. Kun, H. A. Carmona, J. S. Andrade Jr., and H. J. Herrmann Department of Theoretical Physics, University of Debrecen, P. O. Box:5, H-4010 Debrecen, Hungary 2 Computational Physics, IfB, HIF, E12, ETH, Hönggerberg, 8093 Zürich, Switzerland 3 Centro de Ciências e Tecnologia, Universidade Estadual do Ceará, 60740-903 Fortaleza, Ceará, Brazil 4 Departamento de F́ısica, Universidade Federal do Cear...

ar X iv : 0 80 1 . 35 64 v 1 [ as tr o - ph ] 2 3 Ja n 20 08 Local Phase Space - Shaped by Chaos ?

ar X iv : 0 80 6 . 42 65 v 1 [ he p - th ] 2 6 Ju n 20 08 Relation Between Holonomy Groups in Superstrings , M and F - theories

We consider manifolds with special holonomy groups SU(3), G2 and Spin(7) as suitable for compactification of superstrings, M-theory and F-theory (with only one time) respectively. The relations of these groups with the octonions are discussed, reinforcing their role in the physics of string theory and duality. We also exhibit three triple exact sequences explaining the connections between the m...

ar X iv : 0 80 2 . 38 39 v 1 [ m at h . G R ] 2 6 Fe b 20 08 Quadratic equations over free groups are NP - complete

We prove that the problems of deciding whether a quadratic equation over a free group has a solution is NP-complete

ar X iv : 0 80 6 . 44 99 v 1 [ m at h . G N ] 2 7 Ju n 20 08 Aronszajn Compacta ∗

We consider a class of compacta X such that the maps from X onto metric compacta define an Aronszajn tree of closed subsets of X.