A prescription for probabilities in eternal inflation

Some of the parameters we call ``constants of Nature'' may in fact be variables related to the local values of some dynamical fields. During inflation, these variables are randomized by quantum fluctuations. In cases when the variable in question (call it $\chi$) takes values in a continuous range, all thermalized regions in the universe are statistically equivalent, and a gauge invariant procedure for calculating the probability distribution for $\chi$ is known. This is the so-called ``spherical cutoff method''. In order to find the probability distribution for $\chi$ it suffices to consider a large spherical patch in a single thermalized region. Here, we generalize this method to the case when the range of $\chi$ is discontinuous and there are several different types of thermalized region. We first formulate a set of requirements that any such generalization should satisfy, and then introduce a prescription that meets all the requirements. We finally apply this prescription to calculate the relative probability for different bubble universes in the open inflation scenario.Comment: 15 pages, 5 figure

The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies

Recent estimates of cosmological parameters derived from Cosmic Microwave Background (CMB) anisotropies are based on the assumption that we know the precise amount of energy density in relativistic particles in the universe, $\omega_{rel}$, at all times. There are, however, many possible mechanisms that can undermine this assumption. In this paper we investigate the effect that removing this assumption has on the determination of the various cosmological parameters. We obtain fairly general bounds on the redshift of equality, $z_{eq}= \omega_{m}/\omega_{rel}=3100_{-400}^{+600}$. We show that $\omega_{rel}$ is nearly degenerate with the amount of energy in matter, $\omega_m$, and that its inclusion in CMB parameter estimation also affects the present constraints on other parameters such as the curvature or the scalar spectral index of primordial fluctuations. This degeneracy has the effect of limiting the precision of parameter estimation from the MAP satellite, but it can be broken by measurements on smaller scales such as those provided by the Planck satellite mission.Comment: 9 pages, 6 figures, Submitted to MNRAS. High resolution colour pictures can be obtained on request from the author

The Effect of a Family Policy Reform on Mother’s Pay: A Natural Experiment Approach

All parents in Norway with children aged one to three, who do not attend publicly subsidised day care, are entitled to a cash-for-care (CFC) subsidy. Studies have shown that the reform has reduced mother’s labour supply. In this paper we analyse wage effects of the reform. We put forward a framework for evaluating reforms when reforms are uniformly and equally accessible nation-wide. First, running a simple Difference in differences (DD) analysis, results suggest that the CFC reform has reduced the mother’s wages. However, after controlling for “the age of the child” effect, by running a triple difference approach, we no longer find any evidence of negative wage effects. Copyright Springer Science+Business Media, Inc. 2005child care, wages, public policy, difference-in-differences-in-differences,

Observation of semileptonic charmless B meson decays

A detailed study of the lepton momentum spectrum in υ(4S) decays has been made using the ARGUS detector at the DORIS II e+e− storage ring at DESY. In the region from 2.3 to 2.6 GeV/c, which is above the endpoint for contributions from B decays via b→c transitions, we observe 41±10 events in excess of known backgrounds. These events are interpreted as a signal for b→u transitions. A model dependent value of 0.10±0.01 is obtained for the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |Vub|/|Vcv|, using the Altarelli et al. model

Search for the rare decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-)

A search for the decays Bs0→μ+μ- and B 0→μ +μ - is performed with 0.37 fb -1 of pp collisions at s=7 TeV collected by the LHCb experiment in 2011. The upper limits on the branching fractions are B(Bs0→μ+μ-)<1.6×10-8 and B(B0→μ+μ-)<3.6×10-9 at 95% confidence level. A combination of these results with the LHCb limits obtained with the 2010 dataset leads to B(Bs0→μ+μ-)<1.4×10-8 and B(B0→μ+μ-)<3.2×10-9 at 95% confidence level. © 2012 CERN