18 research outputs found
Search for subsolar-mass black hole binaries in the second part of Advanced LIGOâs and Advanced Virgoâs third observing run
We describe a search for gravitational waves from compact binaries with at least one component with mass 0.2âMââ1.0âMâ and mass ratio q â„ 0.1 in Advanced LIGO and Advanced Virgo data collected between 1 November 2019, 15:00 UTC and 27 March 2020, 17:00 UTC. No signals were detected. The most significant candidate has a false alarm rate of 0.2yrâ1
â . We estimate the sensitivity of our search over the entirety of Advanced LIGOâs and Advanced Virgoâs third observing run, and present the most stringent limits to date on the merger rate of binary black holes with at least one subsolar-mass component. We use the upper limits to constrain two fiducial scenarios that could produce subsolar-mass black holes: primordial black holes (PBH) and a model of dissipative dark matter. The PBH model uses recent prescriptions for the merger rate of PBH binaries that include a rate suppression factor to effectively account for PBH early binary disruptions. If the PBHs are monochromatically distributed, we can exclude a dark matter fraction in PBHs fPBH âłâ0.6 (at 90% confidence) in the probed subsolar-mass range. However, if we allow for broad PBH mass distributions we are unable to rule out fPBH = 1. For the dissipative model, where the dark matter has chemistry that allows a small fraction to cool and collapse into black holes, we find an upper bound fDBH < 10â5 on the fraction of atomic dark matter collapsed into black holes
AnĂĄlisis Plural, segundo semestre 2021: A medio trecho, AMLO y la 4T
Con este nĂșmero termina la primera Ă©poca de la colecciĂłn AnĂĄlisis Plural y se ofrece un artĂculo especial para reflexionar sobre lo que ha significado esta publicaciĂłn desde su fundaciĂłn, hace 33 años. En lo correspondiente al anĂĄlisis del segundo semestre del 2021, los artĂculos llevan a la reflexiĂłn sobre los aspectos positivos y negativos de la gestiĂłn presidencial de AndrĂ©s Manuel LĂłpez Obrador; se abordan tambiĂ©n los rasgos de la polĂtica educativa y econĂłmica; el caso de los Papeles de Pandora y los resultados de la iniciativa que eliminĂł el outsourcing; ante la decisiĂłn de cerrar las escuelas por la pandemia se analizan los dilemas de la enseñanza remota; se plasman las causas de la migraciĂłn y las estrategias que miles de familias aplican para garantizar su trĂĄnsito por MĂ©xico; con relaciĂłn al cambio climĂĄtico se expone la poca relevancia que el gobierno de la 4T ha manifestado sobre esta problemĂĄtica y, para cerrar el anĂĄlisis se ofrece una crĂłnica de la resistencia de TemacapulĂn, Acasico y Palmarejo, para salvar su territorio ante la construcciĂłn de la presa El Zapotillo que amenazĂł con inundar sus pueblos.ITESO, A.C
Study and modeling of high-density polyethylene coalescence under the extrussion conditions
Enhancing self-regulation and approaches to learning in first-year college students: a narrative-based programme assessed in the Iberian Peninsula
A programme to enhance first-year college studentsâ self-regulated learning
strategies is proposed and assessed in two samples, one from the University of Oviedo
(Spain) and the other from the University of Minho (Portugal). Each sample was
divided into two groups (experimental and control). The Spanish sample comprised 44
students in the experimental group and 40 in the control group, whereas in the
Portuguese sample, the number of students was 48 and 44, respectively. The narrativebased
intervention programme is organised around a set of fictional letters from a first-year college student in which he reports his own academic experiences. Each letter
focuses on a learning strategy as an opportunity to teach and enhance the studentsâ deep
approaches to learning and their self-regulated learning processes. In both samples,
findings confirm the programme efficacy to teach efficient learning strategies and to
promote self-regulation. Implications for college students and for teaching are discussed