ar X iv : h ep - t h / 02 03 25 9 v 1 2 7 M ar 2 00 2 SU - 4240 - 758 Quantum Spacetimes in the Year 1 1

ar X iv : h ep - t h / 07 03 25 6 v 1 2 8 M ar 2 00 7 NIKHEF / 2007 - 008 VANISHING SCALAR INVARIANT SPACETIMES IN SUPERGRAVITY

We show that the higher-dimensional vanishing scalar invariant (VSI) spacetimes with fluxes and dilaton are solutions of type IIB supergravity, and we argue that they are exact solutions in string theory. We also discuss the supersymmetry properties of VSI spacetimes. [PACS: 04.20.Jb, 04.65.+e]

ar X iv : h ep - t h / 02 11 04 8 v 1 7 N ov 2 00 2 Inflation , Quantum Cosmology and the Anthropic Principle 1

ar X iv : h ep - p h / 07 03 29 7 v 1 2 8 M ar 2 00 7 Introduction to Chiral Perturbation Theory

A brief introduction to chiral perturbation theory, the effective field theory of quantum chromodynamics at low energies, is given.

ar X iv : h ep - p h / 01 03 31 7 v 1 2 9 M ar 2 00 1 g - 2 in composite models of leptons

Based on the bound state description of muon and general relativistic covariant quantum field theory, we illustrate with a simple composite model that the observed deviation of (g − 2)μ can be a demonstration of the substructure of muon and give a constraint on the radius of muon in a light constituent model or the masses of constituents in a heavy constituent model.

ar X iv : h ep - p h / 02 03 14 6 v 1 1 5 M ar 2 00 2 GUTPA / 02 / 03 / 01 Could there be a Fourth Generation ? ∗

We investigate the possibility of incorporating a chiral fourth generation into a GUT model. We find that in order to do so, precision fits to electroweak observables demand the introduction of light (< MZ) su-persymmetric particles. This also enables us to provide decay channels to the fourth-generation quarks. Perturbative consistency sets an upper bound on the coloured supersymmetric spectru...