Related papers: The Current Status of Primary Distance Indicators
The extremes of a stationary time series typically occur in clusters. A primary measure for this phenomenon is the extremal index, representing the reciprocal of the expected cluster size. Both a disjoint and a sliding blocks estimator for…
By observing the transits of exoplanets, one may determine many fundamental system parameters. I review current techniques and results for the parameters that can be measured with the greatest precision, specifically, the transit times, the…
The popularity of pulsating stars resides in their capacity of determining several crucial and relevant parameters such as heliocentric distances, ages, metallicity gradients and reddening. RR Lyrae stars are old stellar tracers and have…
Over the last few decades, exhaustive surveys of extra Galactic globular clusters (EGGCs) have become feasible. Only recently, kinematical information of globular clusters (GCs) were available through Gaia DR2 spectroscopy and also proper…
The reversible spreading processes with repeated infection widely exist in nature and human society, such as gonorrhea propagation and meme spreading. Identifying influential spreaders is an important issue in the reversible spreading…
To investigate non-linear dynamical systems, like for instance artificial satellites, Solar System, exoplanets or galactic models, it is necessary to have at hand several tools, such as a reliable dynamical indicator. The aim of the present…
A model for the mass in and around the Local Group previously used to fit redshifts of dwarf galaxies to their distances between 50 kpc and 2.6 Mpc under the condition of small and growing primeval departures from homogeneity is shown to…
Purpose: RR Lyrae stars are important distance indicators. They are usually present in globular clusters where they were first discovered. The study of their properties and distribution in our Galaxy and external galaxies constitutes a…
Pulsar astronomy is currently enjoying one of the most productive phases in its history. In this review, I outline some of the basic observational aspects and summarise some of the latest results of searches for pulsars in the disk of our…
We consider a family of periodic SEIRS epidemic models with a fairly general incidence rate and it is shown the basic reproduction number determines the global dynamics of the models and it is a threshold parameter for persistence.…
Numerical simulations of star cluster formation have advanced greatly during the past decade, covering increasingly massive gas clouds while accounting for more and more complex physics. In this review, I discuss the present state of the…
In the era of precision cosmology the Virgo cluster takes on a new role in the cosmic distance scale. Its traditional role of testing the consistency of secondary distance indicators is replaced by an ensemble of distance measurements…
Our knowledge of the dynamics and masses of galaxies in the Local Group has long been limited by the fact that only line-of-sight velocities were observationally accessible. This introduces significant degeneracies in dynamical models,…
Conformational transitions are ubiquitous in biomolecular systems, have significant functional roles and are subject to evolutionary pressures. Here we provide a first theoretical framework for topological transition, i.e. conformational…
We measure the half-light radii of globular clusters (GCs) in 43 galaxies from the ACS Fornax Cluster Survey (ACSFCS). We use these data to extend previous work in which the environmental dependencies of the half-light radii of GCs in early…
High precision trigonometric parallaxes from the HIPPARCOS satellite and accurate metal abundances ([Fe/H], [O/Fe], and [alpha/Fe]) from high resolution spectroscopy for about 30 local subdwarfs have been used to derive distances and ages…
We use masses, radii, and luminosities of the detached eclipsing binary OGLEGC17 derived from photometric and spectroscopic observations to calculate the age and distance of the globular cluster omega Cen. Age versus turnoff mass and age…
The construction of a radar coordinate system about the world line of an observer is discussed. Radar coordinates for a hyperbolic observer as well as a uniformly rotating observer are described in detail. The utility of the notion of radar…
How to evaluate the importance of nodes is essential in research of complex network. There are many methods proposed for solving this problem, but they still have room to be improved. In this paper, a new approach called local volume…
Urban mobility models are essential tools for understanding and forecasting how people and goods move within cities, which is vital for transportation planning. The spatial scale at which urban mobility is analysed is a crucial determinant…