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Related papers: Ultra Long-Term Cosmology and Astrophysics

200 papers

We explore the dynamics and evolution of the Universe at early and late times, focusing on both dark energy and extended gravity models and their astrophysical and cosmological consequences. Modified theories of gravity not only provide an…

In the next few years, the 21cm line will enable direct observations of the Dark Ages, Cosmic Dawn, and Reionization, which represent previously unexplored periods in our cosmic history. With a combination of sky-averaged global signal…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Adrian Liu , H. Cynthia Chiang , Abigail Crites , Jonathan Sievers , Renée Hložek

The exploration of the redshift drift, a direct measurement of cosmological expansion, is expected to take several decades of observation with stable, sensitive instruments. We introduced a new method to probe cosmology which bypasses the…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Chengyi Wang , Krzysztof Bolejko , Geraint F. Lewis

In the past decade, observational cosmology has had one of the most exciting periods in the past century. The precision with which we have been able to measure cosmological parameters has increased tremendously, while at the same time, we…

Astrophysics · Physics 2009-11-07 Lawrence M. Krauss

Direct measurement of acceleration is a key scientific goal for both cosmology and exoplanets. For cosmology, the concept of redshift drift (more than 60 years old by the 2020s) could directly establish the…

Abridged: The golden age of astrophysics is upon us with both grand discoveries (extra-solar planets, dark matter, dark energy) and precision cosmology. Fundamental understanding of the working of stars and galaxies is within reach, thanks…

The most exciting future observation in cosmology will feature a monitoring of the cosmic expansion in real time, unlike anything that has ever been attempted before. This campaign will uncover crucial physical properties of the various…

General Relativity and Quantum Cosmology · Physics 2022-12-14 Fulvio Melia

We show that some primary special relativity effects, which are believed to be hardly detectable in everyday life, such as time dilation, relativistic Doppler effect, and length contraction, should tangibly and spectacularly show up here on…

General Physics · Physics 2022-04-12 Germano D'Abramo

Recent observations of distant supernovae imply, in defiance of expectations, that the universe growth is accelerating, contrary to what has always been assumed that the expansion is slowing down due to gravity. In this paper a…

Astrophysics · Physics 2007-05-23 M. Carmeli , S. Behar

We present explicit expressions for the calculation of cosmological look back time, for zero cosmological constant and arbitrary density parameter $\Omega$, which, in the limit as redshift becomes infinite, give the age of the universe. The…

Astrophysics · Physics 2007-05-23 Kevin Krisciunas

Breakthroughs in physics and astrophysics are often driven by technological advances, with the recent detection of gravitational waves being one such example. This white paper focuses upon how improved astrometric and spectroscopic…

The mood at this conference is summarized in David Hughes' comment, ``this decade will be amazing.'' We've just had a pretty good ten years of advances in cosmology and extragalactic astronomy; why should we expect a repeat, another decade…

Astrophysics · Physics 2017-03-29 P. J. E. Peebles

The current state of cosmology is easy to summarize: a very successful standard model -- the hot big-bang cosmology -- that accounts for the evolution of the Universe from 10^{-2} sec until the present; bold ideas based upon early-Universe…

Astrophysics · Physics 2009-10-30 Michael S. Turner

This paper outlines astrophysical issues related to the long term fate of the universe. We consider the evolution of planets, stars, stellar populations, galaxies, and the universe itself over time scales which greatly exceed the current…

Astrophysics · Physics 2008-11-26 Fred C. Adams , Gregory Laughlin

The main argument that Universe is currently expanding is observed redshift increase by distance. However, this conclusion may not be correct, because cosmological redshift depends only on the scaling factors, the change in the size of the…

General Physics · Physics 2012-07-05 Branislav Vlahovic

The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$\alpha$ absorption lines), that might be directly observed by future ultra…

Astrophysics · Physics 2009-11-13 A. Balbi , C. Quercellini

Galaxy redshift surveys have achieved significant progress over the last couple of decades. Those surveys tell us in the most straightforward way what our local universe looks like. While the galaxy distribution traces the bright side of…

Astrophysics · Physics 2015-06-24 Ofer Lahav , Yasushi Suto

The observed late-time acceleration of the Universe may be the result of unknown physical processes involving either modifications of gravitation theory or the existence of new fields in high energy physics. In the former case, such…

Astrophysics · Physics 2008-11-26 N. Pires , Zong-Hong Zhu , J. S. Alcaniz

We study cosmological constraints on the various accelerating models of the universe using the time evolution of the cosmological redshift of distant sources. The important characteristic of this test is that it directly probes the…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Deepak Jain , Sanjay Jhingan

In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the…

Astrophysics · Physics 2009-11-11 Gabriela Barenboim , Olga Mena Requejo , Chris Quigg