ar X iv : 0 90 2 . 36 42 v 1 [ he p - th ] 2 0 Fe b 20 09 Classification of IIB backgrounds with 28 supersymmetries

ar X iv : 0 90 2 . 03 00 v 2 [ he p - th ] 1 3 Fe b 20 09 Calculable membrane theory

The key to membrane theory is to enlarge the diffeomorphism group until 4D gravity becomes almost topological. Just one ghost survives and its central charges can cancel against matter. A simple bosonic membrane emerges, but its flat D = 28 target space is unstable. Adding supersym-metry ought to give calculable (2,2) membranes in 12 target dimensions, but (2,1) membranes won't work.

ar X iv : 0 90 2 . 41 09 v 1 [ he p - ph ] 2 4 Fe b 20 09 pp̄ → Λ c Λ̄ c within a Handbag Picture – Cross

We study the process pp̄ → ΛcΛ̄c within the generalized parton picture. Our starting point is the double handbag diagram which factorizes into soft generalized parton distributions and a hard subprocess amplitude for uū → cc̄. Our cross-section predictions may become interesting in view of forthcoming experiments at FAIR in Darmstadt.

ar X iv : 0 90 2 . 17 29 v 1 [ m at h . N T ] 1 0 Fe b 20 09 ON THE DIMENSION OF AG TRACE CODES

We determine the dimension of certain q-ary algebraic-geometric codes, extending previous results of Van Der Vlugt for p-ary algebraic-geometric trace codes.

ar X iv : 0 90 2 . 17 91 v 1 [ he p - ph ] 1 1 Fe b 20 09 The Origin of Mass 1 Alfredo Raya

Dynamical chiral symmetry breaking and confinement are two crucial features of Quantum Chromodynamics responsible for the nature of the hadron spectrum. These phenomena, presumably coincidental, can account for 98% of the mass of our visible universe. In this set of lectures, I shall present an introductory review of them in the light of the Schwinger-Dyson equations.

ar X iv : 0 90 2 . 39 12 v 1 [ m at h . G R ] 2 3 Fe b 20 09 Brent Everitt The Combinatorial Topology