Cosmological perturbations in SFT inspired non-local scalar field models

We study cosmological perturbations in models with a single non-local scalar field originating from the string field theory description of the rolling tachyon dynamics. We construct the equation for the energy density perturbations of the non-local scalar field and explicitly prove that for the free field it is identical to a system of local cosmological perturbation equations in a particular model with multiple (maybe infinitely many) local free scalar fields.Comment: 21 pages, no figures, v3: presentation improved, results unchanged, references adde

Solving Singular Control from Optimal Switching

Singular stochastic control, Optimal switching, Dynkin’s game, Reversible investment, Smooth fit principle,

Anyone for higher speed limits? – Self-interested and adaptive political preferences

Swedish survey-evidence indicates that variables reflecting self-interest are important in explaining people’s preferred speed limits, and that political preferences adapt to technological development. Drivers who believe they drive better than the average driver as well as drivers of cars that are newer (and hence safer), bigger, and with better highspeed characteristics, prefer higher speed limits. In contrast, elderly people prefer lower speed limits. Furthermore, people report that they themselves vote more sociotropically than they believe others vote on average, indicating that we may vote less sociotropically than we believe ourselves. One possible reason for such self-serving biases is that people desire to see themselves as socially responsible. Copyright Springer Science + Business Media, Inc. 2005

Review of Particle Physics

This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 1900 new measurements from 700 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. © 1996 The American Physical Society