Related papers: Cosmology in Portugal: The First 20 Years
A brief review is given of the present observational data in cosmology. A review of a new bimetric gravity theory with multiple light cones is presented. The physical consequences of this gravity theory for the early universe are analyzed.
One of the next decade's most exciting prospects is to explore the cosmic "dark ages," during which the first stars in the Universe formed, with the 21 cm line of neutral hydrogen. At z>6, this light redshifts into the low-frequency radio…
In recent years, by theory and observation cosmology has advanced substantially. Parameters of the concordance or $\Lambda$CDM cosmological model are given with unprecedented precision ("precision cosmology"). On the other side, 95% of the…
Astronomy provides a laboratory for extreme physics, a window into environments at extremes of distance, temperature and density that often can't be reproduced in Earth laboratories, or at least not right away. A surprising amount of the…
This article analyses the current state of Astronomy in Argentina and describes its origins. We briefly describe the institutions where astronomical research takes place, the observational facilities available, the training of staff and…
Ten years ago humankind achieved the first direct observation of gravitational waves. I give some personal recollections of that first detection. I also present an incomplete summary of what we have learned since then, and some speculations…
In the century since Einstein's anno mirabilis of 1905, our concept of the Universe has expanded from Kapteyn's flattened disk of stars only 10 kpc across to an observed horizon about 30 Gpc across that is only a tiny fraction of an…
Astroparticle physics has evolved as an interdisciplinary field at the intersection of particle physics, astronomy and cosmology. Over the last two decades, it has moved from infancy to technological maturity and is now envisaging projects…
An introductory lectures on cosmology at ITEP Winter School for students specializing in particle physics are presented. Many important subjects are not covered because of lack of time and space but hopefully the lectures may serve as a…
The AstroCamp is an academic excellence program in the field of astronomy and physics for students in the last 3 years of pre-university education, which often includes a course (or a significant part thereof) on Relativity. After an…
An attempt is made to evaluate progress of the Polish astrophysical research of stars and of the inter-stellar medium (ISM) on the basis of scientific paper citations in the ADS database. Rather modest citation levels were observed in the…
Here follow three reports covering different aspects of the early history from 1964 to 1980 of the Hipparcos satellite mission. The first report "Interviews about the creation of Hipparcos" contains interviews from 2017 with scientists…
Cosmology has come a long way from being based on a small number of observations to being a data-driven precision science. We discuss the questions "What is observable?", "What in the Universe is knowable?" and "What are the fundamental…
This review is an up-to-date account of the use of numerical relativity to study dynamical, strong-gravity environments in a cosmological context. First, we provide a gentle introduction into the use of numerical relativity in solving…
The reports from 2008: "Astrometry and optics during the past 2000 years", are available at arXiv and at my website: www.astro.ku.dk/~erik/History.pdf . Here are now further contributions to the history of astrometry related to space…
We examine astronomical observations that would be achievable over a future timeline corresponding to the documented history of human civilization so far, $\sim 10^4$ years. We examine implications for measurements of the redshift drift,…
Despite much recent theoretical and observational progress in our knowledge of the early universe, many fundamental questions remain only partially answered. Here, we review the latest achievements and persisting problems in the…
In the first part I set out some unexplored historical material about the early development of cosmic topology. In the second part I briefly comment new developments in the field since the Lachieze-Rey & Luminet report (1995), both from a…
Since the dawn of civilization, humanity has grappled with the big questions of existence and creation. Modern cosmology seeks to answer some of these questions using a combination of mathematics and measurement. The questions people hope…
Cosmology is undergoing an explosive period of activity, fueled both by new, accurate astrophysical data and by innovative theoretical developments. Cosmological parameters such as the total density of the Universe and the rate of…