Fast Bayesian gravitational wave parameter estimation using convolutional neural networks

The determination of the physical parameters of gravitational wave events is a fundamental pillar in the analysis of the signals observed by the current ground-based interferometers. Typically, this is done using Bayesian inference approaches which, albeit very accurate, are very computationally expensive. We propose a convolutional neural network approach to perform this task. The convolutional neural network is trained using simulated signals injected in a Gaussian noise. We verify the correctness of the neural network's output distribution and compare its estimates with the posterior distributions obtained from traditional Bayesian inference methods for some real events. The results demonstrate the convolutional neural network's ability to produce posterior distributions that are compatible with the traditional methods. Moreover, it achieves a remarkable inference speed, lowering by orders of magnitude the times of Bayesian inference methods, enabling real-time analysis of gravitational wave signals. Despite the observed reduced accuracy in the parameters, the neural network provides valuable initial indications of key parameters of the event such as the sky location, facilitating a multi-messenger approach

Determination of the light exposure on the photodiodes of a new instrumented baffle for the Virgo input mode cleaner end-mirror

As part of the upgrade program of the Advanced Virgo interferometer, the installation of new instrumented baffles surrounding the main test masses is foreseen. As a demonstrator, and to validate the technology, the existing baffle in the area of the input mode cleaner end-mirror will be first replaced by a baffle equipped with photodiodes. This paper presents detailed simulations of the light distribution on the input mode cleaner baffle, with the aim to determine the light exposure of the photodiodes under different scenarios of the interferometer operation.Comment: 9 pages and 8 figure

Determination of the light exposure on the photodiodes of a new instrumented baffle for the Virgo input mode cleaner end-mirror

As part of the upgrade program of the advanced Virgo interferometer, the installation of new instrumented baffles surrounding the main test masses is foreseen. As a demonstrator, and to validate the technology, the existing baffle in the area of the input mode cleaner end-mirror will be first replaced by a baffle equipped with photodiodes. This paper presents detailed simulations of the light distribution on the input mode cleaner baffle. They served to validate the proposed layout of the sensors in the baffle, and determine the light exposure of the photodiodes under different scenarios of the interferometer operations, in order to define mitigation strategies for preserving the detector integrity

A study of top polarization in single-top production at the LHC

This paper complements the study of single top production at the LHC aiming to estimate the sensitivity of different observables to the magnitude of the effective couplings. In a previous paper the dominant $W$-gluon fusion mechanism was considered, while here we extend the analysis to the subdominant (10% with our set of experimental cuts) s-channel process. In order to distinguish left from right effective couplings it is required to consider polarized cross-sections and/or include $m_b$ effects. The spin of the top is accessible only indirectly by measuring the angular distribution of its decay products. We show that the presence of effective right-handed couplings implies necessarily that the top is not in a pure spin state. We discuss to what extent quantum interference terms can be neglected in the measurement and therefore simply multiply production and decay probabilities clasically. The coarsening involved in the measurement process makes this possible. We determine for each process the optimal spin basis where theoretical errors are minimized and, finally, discuss the sensitivity in the s-channel to the effective right-handed coupling. The results presented here are all analytical and include $m_b$ corrections. They are derived within the narrow width approximation for the top.Comment: 30 pages, 14 figure

Measurement of the Stray Light in the Advanced Virgo Input Mode Cleaner Cavity using an instrumented baffle

A new instrumented baffle was installed in Spring 2021 at Virgo surrounding the suspended mirror in the input mode cleaner triangular cavity. It serves as a demonstrator of the technology designed to instrument the baffles in the main arms in the near future. We present, for the first time, results on the measured scattered light distribution inside the cavity as determined by the new device using data collected between May and July 2021, with Virgo in commissioning phase and operating with an input laser power in the cavity of 28.5~W. The sensitivity of the baffle is discussed and the data is compared to scattered light simulations.Comment: 4 pages, 5 figures, 1 tabl

Revisión bibliográfica de implantología bucofacial del año 2009. 2ª parte

Debido al amplio número de publicaciones que existen sobre Implantología Bucofacial, resulta difícil para el odontólogo seleccionar y leer de forma crítica una cantidad suficiente de artículos que puedan aportarle una información útil para su praxis diaria. En este artículo pretendemos sintetizar la información más relevante que se encuentra en las revistas indexadas de la especialidad publicadas el año 2009

Revisión bibliográfica de implantología bucofacial del año 2009. 1ª parte

Debido al amplio número de publicaciones que existen sobre Implantología Bucofacial, resultadifícil para el odontólogo seleccionar y leer de forma crítica una cantidad suficiente de artículos que puedan aportarle una información útil para su praxis diaria. En este artículo se pretende sintetizar la información más relevante que se encuentra en las revistas indexadas de la especialidad publicadas durante el año 2009

Revisión bibliográfica de implantología bucofacial del año 2009. 2ª parte

Debido al amplio número de publicaciones que existen sobre Implantología Bucofacial, resulta difícil para el odontólogo seleccionar y leer de forma crítica una cantidad suficiente de artículos que puedan aportarle una información útil para su praxis diaria. En este artículo pretendemos sintetizar la información más relevante que se encuentra en las revistas indexadas de la especialidad publicadas el año 2009