Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

FIRST SEARCHES FOR OPTICAL COUNTERPARTS TO GRAVITATIONAL-WAVE CANDIDATE EVENTS

During the LIGO and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers showed strong evidence for being astrophysical in nature. We compare the sensitivities of these observations to several model light curves from possible sources of interest, and discuss prospects for future joint GW-optical observations of this type

On the progenitor of binary neutron star merger GW170817

On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just ∼40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of ∼2 kpc away from the galaxy's center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy's star formation history, provided the stellar populations are older than 1 Gyr

Constraints on cosmic strings using data from the first Advanced LIGO observing run

Cosmic strings are topological defects which can be formed in grand unified theory scale phase transitions in the early universe. They are also predicted to form in the context of string theory. The main mechanism for a network of Nambu-Goto cosmic strings to lose energy is through the production of loops and the subsequent emission of gravitational waves, thus offering an experimental signature for the existence of cosmic strings. Here we report on the analysis conducted to specifically search for gravitational-wave bursts from cosmic string loops in the data of Advanced LIGO 2015-2016 observing run (O1). No evidence of such signals was found in the data, and as a result we set upper limits on the cosmic string parameters for three recent loop distribution models. In this paper, we initially derive constraints on the string tension Gμ and the intercommutation probability, using not only the burst analysis performed on the O1 data set but also results from the previously published LIGO stochastic O1 analysis, pulsar timing arrays, cosmic microwave background and big-bang nucleosynthesis experiments. We show that these data sets are complementary in that they probe gravitational waves produced by cosmic string loops during very different epochs. Finally, we show that the data sets exclude large parts of the parameter space of the three loop distribution models we consider

Health Promotion And Leadership Networks [promoção Da Saúde E Redes De Lideranças]

The study of social networks has been gaining importance in health promotion because of the horizontality and synergy created by aggregating groups seeking improved living conditions. Some results of the investigation "Capela in Action and the integrated and participative management of public policies", which assessed an administrative model of the Capela do Socorro subprefecture, in southern São Paulo city, are presented. The analysis of the data addressed the relationships between local leaders, their integration into networks and how far these relationships facilitate actions seeking improved living conditions. The universe of leaders and entities was not defined a priori, but empirically from references collected in the field by the snowball technique. Semi-structured interviews identified groups, movements and entities and their relationships with local government. The data identified 247 leadership positions, 342 associations and complexities of the administrative model studied, within the perspective of the construction of social and political networks as instruments of popular participation. Analyses showed that in inter-group relationships, presented as a sociogram, diffuse connections characterized an extensive, sparse network. Changes are underway in civil society, both in organization and social transformation. Some facts pointed here provide local administration with information to create new opportunities for participation and facilitate local leaders' involvement in the implementation of public policies.231209226Biernacky, P., Walford, D., Snowball sampling: Problems and techniques of chaim referral sampling (1981) Sociol Methods Research, (2), pp. 141-163Borgatti, S.P., Everett, M.G., Freeman, L.C., (2002) Ucinet for Windows: Software for Social Network Analysis, , Harvard: Analytic TechnologiesBuss, P.M., Pellegrini Filho, A., A saúde e seus determinantes (2007) PHYSIS: Rev. Saúde Coletiva, 17 (1), pp. 77-93. , Rio de JaneiroCastells, M., (1999) A sociedade em rede, , São Paulo: Paz e TerraCastells, M., O poder da identidade (2006) Era da Informação, Sociedade e Cultura, , In: CASTELLS, M. A, V.2. São Paulo: Paz e TerraCzeresnia, D., O conceito de saúde e a diferença entre prevenção e promoção (2003) Promoção da Saúde: Conceitos, reflexões, tendências, pp. 39-53. , In: CZERESNIA, D.FREITAS, C.M. (Org.), Rio de Janeiro: FiocruzFernandez, J.C.A., Autonomia e promoção da saúde (2012) Educação e promoção da saúde: Teoria e prática, pp. 499-512. , In: PELICIONI M.C.F.MIALHE, F.L. (Ed.)., São Paulo: SantosGohn, M.G., (2005) Protagonismo da sociedade civil: Movimentos sociais, ONG's e redes solidárias, , São Paulo: Cortez, (Coleção Questões da Nossa Época, v.123)Gurza-Lavalle, A.G., Castello, G., Bichir, R.M., Quando novos atores saem de cena-continuidades e mudanças na centralidade dos movimentos sociais (2004) Política & Sociedade, 5 (2), pp. 35-54. , FlorianópolisGurza-Lavalle, A.G., Castello, G., Bichir, R.M., Protagonistas na sociedade civil: Redes e centralidades de organizações civis em São Paulo (2007) Dados, 50 (3), pp. 465-498. , Rio de JaneiroGurza-Lavalle, A.G., Castello, G., Bichir, R.M., Atores periféricos na sociedade civil: Redes, centralidades e organizações civis em São Paulo (2008) Revista Brasileira de Ciências Sociais, 23 (68), pp. 73-96Lopes, C.S., Rodrigues, L.C., Sichieri, R., The lack of selection bias in a snowball sampled case-control study on drug abuse (1996) International Journal of Epidemiology, 25 (6), pp. 1267-1270Marques, E.C., Redes sociais e institucionais na construção do Estado e da sua permeabilidade (1999) Revista Brasileira de Ciências Sociais, 14 (41), pp. 45-67. , São PauloMarteleto, R.M., Ribeiro, B., Guimarães, C., Informação em movimento: Produção e organização do conhecimento nos espaços sociais (2002) Civitas, 2 (1), pp. 69-80. , Porto AlegreConferência Mundial sobre os Determinantes Sociais da Saúde (2012) Diminuindo as diferenças: A prática das políticas sobre os determinantes sociais de saúde, , http://www.who.int/sdhconference/discussion_paper/Discussion_Paper_PT.pdf, ORGANIZAÇÃO MUNDIAL DA SAÚDE, Documento para discussão. Rio de Janeiro, out 2011. Disponível em:. Acesso em: 16 novScherer-Warren, I., (1996) Redes de movimentos sociais, , 2a ed. São Paulo: LoyolaScherer-Warren, I., Redes de movimentos sociais na América Latina (2008) Caderno CRH, 21 (54), pp. 505-517. , set-dezStoz, E.N., Redes sociais e saúde (2009) Informação, saúde e redes sociais: Diálogos de conhecimentos nas comunidades da Maré, pp. 27-42. , In: MARTELETO, R.M. (Org)., Rio de Janeiro: FiocruzWestphal, M.F., (2008) Capela em ação e a gestão integrada e participativa de políticas públicas, p. 205. , Relatório Técnico. São Paulo: FapespWhitaker, F., Rede: Uma estrutura alternativa de organização (2002) Revista Mutações sociais, (3). , Rio de Janeiro, s/