Astrophysical and Theoretical Physics Implications from Multimessenger Neutron Star Observations.

The Neutron Star Interior Composition Explorer (NICER) recently measured the mass and equatorial radius of the isolated neutron star PSR J0030+0451. We use these measurements to infer the moment of inertia, the quadrupole moment, and the surface eccentricity of an isolated neutron star for the first time, using relations between these quantities that are insensitive to the unknown equation of state of supranuclear matter. We also use these results to forecast the moment of inertia of neutron star A in the double pulsar binary J0737-3039, a quantity anticipated to be directly measured in the coming decade with radio observations. Combining this information with the measurement of the tidal Love number with LIGO/Virgo observations, we propose and implement the first theory-agnostic and equation-of-state-insensitive test of general relativity. Specializing these constraints to a particular modified theory, we find that consistency with general relativity places the most stringent constraint on gravitational parity violation to date, surpassing all other previously reported bounds by 7 orders of magnitude and opens the path for a future test of general relativity with multimessenger neutron star observations.

Guía de referencia para investigadores no expertos en el uso de estadística multivariada / Reference guide for non-expert researchers in multivariate statistics

Quienes se inician en la investigación suelen encontrarse con dificultades en el análisis estadístico de los datos para la verificación de su hipótesis de trabajo, particularmente en la selección de la técnica estadística apropiada, su aplicación e interpretación. Se plantea que lo anterior resulta de una actitud negativa hacia el análisis cuantitativo, relacionado con dificultades percibidas en clases de estadística y metodología de la investigación en educación superior. El objetivo del presente artículo es ofrecer una guía de referencia para investigadores no expertos en el uso de algunas técnicas estadísticas con amplia aplicación en la generación de conocimiento. Se define cada técnica multivariada presentada y se especifican las condiciones en las cuales es posible su aplicación enumerando los supuestos mínimos que debe cumplir. Adicionalmente, se presentan tres ejemplos que muestran las inconsistencias estadísticas que resultan de no considerar algunos supuestos en el análisis de los datos.

New researchers often face difficulties in the statistical analysis of data for verification of the working hypotheses, particularly in the selection of an appropriate statistical technique, its application and interpretation. It is often argued that the foregoing of a negative attitude toward the quantitative analysis related to perceived difficulties in statistics classes and research methodology in education. The purpose of this article is to provide a reference guide for non-expert researchers in the use of some statistical techniques with broad applications in the generation of knowledge. Each multivariate technique is defined and the conditions under which it is possible its application are enumerated, presenting the minimum conditions to be met. In addition, three examples are presented showing inconsistencies resulting from a wrong use of statistics and assumptions in analyzing the data.