Effect of ammonium bisulphite and chloride on the pitting and stress corrosion cracking resistance of super duplex stainless steel pipes under combined internal pressure and axial tension

The financial support of Shell UK is acknowledged. The authors would like to thank the following technical staff, Stuart Herbert, Alistair Robertson for the machining of the mini pipes, Derek Logan, and Irene Brand for resolving several electrical issues and providing accessories, and Jim Gall for help with the test set‐up and prompt supply of tools and equipment.Peer reviewedPostprin

BPS partition functions in N = 4 Yang-Mills theory on T^4

We consider N = 4 Yang-Mills theory on a flat four-torus with the R-symmetry current coupled to a flat background connection. The partition function depends on the coupling constant of the theory, but when it is expanded in a power series in the R-symmetry connection around the loci at which one of the supersymmetries is unbroken, the constant and linear terms are in fact independent of the coupling constant and can be computed at weak coupling for all non-trivial 't Hooft fluxes. The case of a trivial 't Hooft flux is difficult because of infrared problems, but the corresponding terms in the partition function are uniquely determined by S-duality.Comment: 23 pages, v2 Minor correction

Octonionic black holes

Using algebraic tools inspired by the study of nilpotent orbits in simple Lie algebras, we obtain a large class of solutions describing interacting non-BPS black holes in N=8 supergravity, which depend on 44 harmonic functions. For this purpose, we consider a truncation E6(6) / Sp(8,R) of the non-linear sigma model describing stationary solutions of the theory, which permits a reduction of algebraic computations to the multiplication of 27 by 27 matrices. The lift to N=8 supergravity is then carried out without loss of information by using a pertinent representation of the moduli parametrizing E7(7) / SU(8) in terms of complex valued Hermitian matrices over the split octonions, which generalise the projective coordinates of exceptional special Kaehler manifolds. We extract the electromagnetic charges, mass and angular momenta of the solutions, and exhibit the duality invariance of the black holes distance separations. We discuss in particular a new type of interaction which appears when interacting non-BPS black holes are not aligned. Finally we will explain the possible generalisations toward the description of the most general stationary black hole solutions of N=8 supergravity.Comment: 90 pages, Corrected version for publication in JHE