New Physics with three-photon events at LEP

The effect of the most general \z3gt vertex in the reaction e^+e^- \ra 3\gamma is studied with a particular attention to LEP searches. We give exact analytical expressions including realistic cuts for the signal and present a detailed analysis based on a Monte Carlo that includes the effect of the irreducible $3\gamma$ QED cross section. As special applications we discuss the effect of heavy scalars, fermions and gauge bosons and comment on the ``monopole" connection.Comment: No changes made from previous version, 34 pages, LateX, uses epsf, 11 .eps figs., full paper (including figs) is also available via WWW at http://lapphp0.in2p3.fr/preplapp/psth/lastee3g.ps.gz or via anonymous ftp at ftp:///lapphp0.in2p3.fr/pub/preprints-theorie/ftpee3g.u

An Empirical Examination of Compensation of REIT Managers

Principal-agent literature finds that manager and owner incentives can be aligned with performance contingent contracts. We investigate the compensation of Real Estate Investment Trust (REIT) industry executives. The competitive nature of mortgage and equity markets, in conjunction with the corporate tax exemption available when REITs distribute most of their earnings as dividends, is likely to influence the compensation of REIT managers. Executive compensation is modeled as a function of revenues and unexpected profit. After transforming the model to reduce collinearity and heteroskedasticity, we find compensation to be generally positively related to revenue. We also find unexpected profit to be generally insignificantly related to compensation, but positively related in those cases where it is significant.

Mortgage Lenders' Market Response to a Landmark Regulatory Decision Based on Fair Lending Compliance

Regulation of real estate lending has substantially increased in the past decade. Government efforts to improve compliance with Community Reinvestment Act mandates are evidence of increased emphasis on racial equal opportunity in loan origination. To investigate the impact of these efforts, this paper examines the Federal Reserve Bank rejection of Shawmut National Corporation's application to buy New Dartmouth Bank. Rejection was based on Shawmut's poor compliance with fair-lending guidelines. Testing finds significant negative abnormal stock returns for samples of mortgage lenders on the announcement day of Shawmut's application rejection. In addition, cross-sectional analysis reveals an inverse relationship between national banks' cumulative abnormal returns (CARs) and a measure of fair lending.

Rethinking Breast Self-Examinations: Are We Asking the Right Questions?

There are a myriad of studies on the efficacy of BSE, with mixed results. Research also highlights growing health disparities and continuing limited access to technology in underserved communities. Results from a pilot study with rural teens suggest that successful skill mastery and sustained practice can be learned. Perhaps most importantly, BSE offers a technology-free method for self-assessment that can be taught at the community level and provides an opportunity for women to gain a measure of self-control over their bodies and themselves

Discussions on "Riemann manifold Langevin and Hamiltonian Monte Carlo methods"

This is a collection of discussions of `Riemann manifold Langevin and Hamiltonian Monte Carlo methods" by Girolami and Calderhead, to appear in the Journal of the Royal Statistical Society, Series B.Comment: 6 pages, one figur

Harold Jeffreys's Theory of Probability Revisited

Published exactly seventy years ago, Jeffreys's Theory of Probability (1939) has had a unique impact on the Bayesian community and is now considered to be one of the main classics in Bayesian Statistics as well as the initiator of the objective Bayes school. In particular, its advances on the derivation of noninformative priors as well as on the scaling of Bayes factors have had a lasting impact on the field. However, the book reflects the characteristics of the time, especially in terms of mathematical rigor. In this paper we point out the fundamental aspects of this reference work, especially the thorough coverage of testing problems and the construction of both estimation and testing noninformative priors based on functional divergences. Our major aim here is to help modern readers in navigating in this difficult text and in concentrating on passages that are still relevant today.Comment: This paper commented in: [arXiv:1001.2967], [arXiv:1001.2968], [arXiv:1001.2970], [arXiv:1001.2975], [arXiv:1001.2985], [arXiv:1001.3073]. Rejoinder in [arXiv:0909.1008]. Published in at http://dx.doi.org/10.1214/09-STS284 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Quantum Gravity and Inflation

Using the Ashtekar-Sen variables of loop quantum gravity, a new class of exact solutions to the equations of quantum cosmology is found for gravity coupled to a scalar field, that corresponds to inflating universes. The scalar field, which has an arbitrary potential, is treated as a time variable, reducing the hamiltonian constraint to a time-dependent Schroedinger equation. When reduced to the homogeneous and isotropic case, this is solved exactly by a set of solutions that extend the Kodama state, taking into account the time dependence of the vacuum energy. Each quantum state corresponds to a classical solution of the Hamiltonian-Jacobi equation. The study of the latter shows evidence for an attractor, suggesting a universality in the phenomena of inflation. Finally, wavepackets can be constructed by superposing solutions with different ratios of kinetic to potential scalar field energy, resolving, at least in this case, the issue of normalizability of the Kodama state.Comment: 18 Pages, 2 Figures; major corrections to equations but prior results still hold, updated reference

Parameterized Inapproximability of Target Set Selection and Generalizations

In this paper, we consider the Target Set Selection problem: given a graph and a threshold value $thr(v)$ for any vertex $v$ of the graph, find a minimum size vertex-subset to "activate" s.t. all the vertices of the graph are activated at the end of the propagation process. A vertex $v$ is activated during the propagation process if at least $thr(v)$ of its neighbors are activated. This problem models several practical issues like faults in distributed networks or word-to-mouth recommendations in social networks. We show that for any functions $f$ and $\rho$ this problem cannot be approximated within a factor of $\rho(k)$ in $f(k) \cdot n^{O(1)}$ time, unless FPT = W[P], even for restricted thresholds (namely constant and majority thresholds). We also study the cardinality constraint maximization and minimization versions of the problem for which we prove similar hardness results

Influence Diffusion in Social Networks under Time Window Constraints

We study a combinatorial model of the spread of influence in networks that generalizes existing schemata recently proposed in the literature. In our model, agents change behaviors/opinions on the basis of information collected from their neighbors in a time interval of bounded size whereas agents are assumed to have unbounded memory in previously studied scenarios. In our mathematical framework, one is given a network $G=(V,E)$, an integer value $t(v)$ for each node $v\in V$, and a time window size $\lambda$. The goal is to determine a small set of nodes (target set) that influences the whole graph. The spread of influence proceeds in rounds as follows: initially all nodes in the target set are influenced; subsequently, in each round, any uninfluenced node $v$ becomes influenced if the number of its neighbors that have been influenced in the previous $\lambda$ rounds is greater than or equal to $t(v)$. We prove that the problem of finding a minimum cardinality target set that influences the whole network $G$ is hard to approximate within a polylogarithmic factor. On the positive side, we design exact polynomial time algorithms for paths, rings, trees, and complete graphs.Comment: An extended abstract of a preliminary version of this paper appeared in: Proceedings of 20th International Colloquium on Structural Information and Communication Complexity (Sirocco 2013), Lectures Notes in Computer Science vol. 8179, T. Moscibroda and A.A. Rescigno (Eds.), pp. 141-152, 201

Foreign offenders in prison and on probation in Europe: Trends from 2005 to 2015 (inmates) and situation in 2015 (inmates and probationers)

Is there really an over-representation of foreign citizens in European prisons? Is the presence of foreign inmates comparable across regions and countries of Europe? How can one explain the differences in the trends shown by the absolute numbers and the percentages of foreign inmates from 2005 to 2015? Do foreign citizens have less access than nationals to alternatives to imprisonment? Do the data available allow the research to establish whether the growth in the use of community sanctions and measures since the 1990s plays a role in the fluctuations observed in the percentage of foreign inmates? The answers to these and many other questions can be found in this book, which compiles and updates a series of specific indicators collected during eleven years through the Council of Europe Annual Penal Statistics (better known as the SPACE statistics), and accompanies the two volumes on Prisons in Europe 2005-2015 published in this collection. The volume includes maps and tables illustrating the state of prison (2005-2015) and probation agencies (2009-2015). In addition, the situation is analyzed through individual country profiles, which include key facts and graphs covering the years 2005 to 2015