Emergence of inflationary perturbations in the CSL model

The inflationary paradigm is the most successful model that explains the observed spectrum of primordial perturbations. However, the precise emergence of such inhomogeneities and the quantum-to-classical transition of the perturbations has not yet reached a consensus among the community. The Continuous Spontaneous Localization model (CSL), in the cosmological context, might be used to provide a solution to the mentioned issues by considering a dynamical reduction of the wave function. The CSL model has been applied to the inflationary universe before and different conclusions have been obtained. In this letter, we use a different approach to implement the CSL model during inflation. In particular, in addition to accounting for the quantum-to-classical transition, we use the CSL model to generate the primordial perturbations, that is, the dynamical evolution provided by the CSL model is responsible for the transition from a homogeneous and isotropic initial state to a final one lacking such symmetries. Our approach leads to results that can be clearly distinguished from preceding works. Specifically, the scalar and tensor power spectra are not time-dependent, and retains the amplification mechanism of the CSL model. Moreover, our framework depends only on one parameter (the CSL parameter) and its value is consistent with cosmological and laboratory observations.Comment: 14 pages. Final version. To be published in EPJ

Bad Apples: Political Paralysis and the Quality of Politicians

Why do elected officials often suffer from political paralysis and fail to implement thebest policies available? This paper considers a new yet intuitive explanation thatfocuses on the quality of the politicians competing to replace the incumbent. Thekey insight is that a 'good' incumbent with preferences identical to those of arepresentative voter will want to keep corrupt politicians out of office; she may do soby distorting her policy choices to signal her type and win re-election. The value ofsignalling and staying in office increases with the fraction of corrupt types in thepopulation of politicians. Electing good types may therefore not be enough to ensurethat the best policies are implemented, especially when corrupt politicians arecommon. This provides a new explanation for why political failure is particularlysevere in corrupt democracies.political agency, corruption, elections, term limits, economic reform,politician quality

Soldiers or Bureaucrats?Conflict and the Military’s Role in Policy-Making

One of the most striking institutional features of many less developed countries is that their militaries are closely involved in policy-making, potentially having a large impact on economic outcomes. This paper examines the role of the military in setting policy. For this purpose it develops one of the first models of the military, where its political involvement can take two forms: direct when the military runs the government, and indirect when it influences policy without governing directly. We focus on civilian regimes and find that war decreases the payoff to the military from both forms of involvement, but also makes staging successful coups easier. In equilibrium, an increase in the likelihood of war makes indirect involvement less likely; its impact on coups, which are aimed at establishing direct control, is non-monotonic. We show empirical evidence for this non-monotonic relationship, withcoups being least likely for low and high probabilities of war.institutions, conflict, political economy, military, war, coups

Quasi-matter bounce and inflation in the light of the CSL model

The Continuous Spontaneous Localization (CSL) model has been proposed as a possible solution to the quantum measurement problem by modifying the Schr\"{o}dinger equation. In this work, we apply the CSL model to two cosmological models of the early Universe: the matter bounce scenario and slow roll inflation. In particular, we focus on the generation of the classical primordial inhomogeneities and anisotropies that arise from the dynamical evolution, provided by the CSL mechanism, of the quantum state associated to the quantum fields. In each case, we obtained a prediction for the shape and the parameters characterizing the primordial spectra (scalar and tensor), i.e. the amplitude, the spectral index and the tensor-to-scalar ratio. We found that there exist CSL parameter values, allowed by other non-cosmological experiments, for which our predictions for the angular power spectrum of the CMB temperature anisotropy are consistent with the best fit canonical model to the latest data released by the Planck Collaboration.Comment: 27 pages, including 6 figures, 2 tables and one Appendix. Final version. Accepted in EPJ

Primordial gravitational waves and the collapse of the wave function

"The self-induced collapse hypothesis" was introduced by D. Sudarsky and collaborators to explain the origin of cosmic structure from a perfect isotropic and homogeneous universe during the inflationary regime. In this paper, we calculate the power spectrum for the tensor modes, within the semiclassical gravity approximation, with the additional hypothesis of a generic self-induced collapse of the inflaton's wave function; we also compute an estimate for the tensor-to-scalar ratio. Based on this calculation, we show that the considered proposal exhibits a strong suppression of the tensor modes amplitude; nevertheless, the corresponding amplitude is still consistent with the joint BICEP/KECK and Planck Collaboration's limit on the tensor-to-scalar ratio.Comment: 18 pages, 2 figures. Replaced to match published versio

Students and the market for schools in Haiti

Uniquely among Latin American and Caribbean countries, Haiti has a largely non-public education system. Prior to the earthquake of January 2010, just 19 percent of primary school students were enrolled in public schools, with the remainder enrolled in a mix of religious, for-profit, and non-governmental organization-funded schools. This paper examines changes in Haitian schooling patterns in the last century and shows the country experienced tremendous growth in school attainment, driven almost entirely by growth in the private sector. Additionally, it provides evidence that the private market"works"to the extent that primary school fees are higher for schools with characteristics associated with education quality. The paper also analyzes the demand and supply determinants of school attendance and finds that household wealth is a major determinant of attendance. Given these findings, the authors conclude that in the near-term paying school fees for poor students may be an effective approach to expanding schooling access in Haiti.Education For All,Tertiary Education,Primary Education,Disability,Gender and Education

Acoustic Identification of Flat Spots On Wheels Using Different Machine Learning Techniques

BMBF, 01IS18049B, ALICE III - Autonomes Lernen in komplexen Umgebungen 3 (Autonomous Learning in Complex Environments 3