Throwing Light on Dark Energy

  title={Throwing Light on Dark Energy},
  author={Robert P. Kirshner},
  pages={1914 - 1918}
Supernova observations show that the expansion of the universe has been speeding up. This unexpected acceleration is ascribed to a dark energy that pervades space. Supernova data, combined with other observations, indicate that the universe is about 14 billion years old and is composed of about 30%matter and 70%dark energy. New observational programs can trace the history of cosmic expansion more precisely and over a larger span of time than has been done to date to learn whether the dark… 

The Dark Age of the Universe

The Cold Dark Matter theory for structure formation predicts that the first sources formed much earlier, and the most distant sources of light known at present are galaxies and quasars at redshift z ≅ 6, and their spectra indicate that the end of reionization was occurring just at that time.

Strangeness, cosmological cold dark matter and dark energy

It is now believed that the universe is composed of a small amount of the normal luminous matter, a substantial amount of matter (cold dark matter (CDM)) which is non-luminous and a large amount of

Dark Energy And Life's Ultimate Future

The discovery of the present accelerated expansion of space changed everything regarding cosmology and life's ultimate prospects. Both the optimistic scenarios of an ever (but decelerated) expanding

Inflationary Cosmology: Exploring the Universe from the Smallest to the Largest Scales

Inflation makes several predictions about the present state of the universe—such as its overall shape, large-scale smoothness, and smaller scale structure—which are being tested to unprecedented accuracy by a new generation of astronomical measurements.

Resource Letter DEAU-1: Dark energy and the accelerating universe

This Resource Letter provides a guide to the literature on dark energy and the accelerating universe. It is intended to be of use to researchers, teachers, and students at several levels. Journal

The Short Spectacular Life of a Superstar

Supernovae are spectacular events--the death throes of stars that can be seen across the universe--and they can leave behind puzzling remnants in the form of neutron stars or black holes. In his

Resource Letter : Dark Energy and the Accelerating Universe

This Resource Letter provides a guide to the literature on dark energy and the accelerating universe. It is intended to be of use to researchers, teachers, and students at several levels. Journal

Hubble’s Law and the expanding universe

  • N. Bahcall
  • Physics
    Proceedings of the National Academy of Sciences
  • 2015
In one of the most famous classic papers in the annals of science, Edwin Hubble’s 1929 PNAS article on the observed relation between distance and recession velocity of galaxies—the Hubble



A theoretician's analysis of the supernova data and the limitations in determining the nature of dark energy

Current cosmological observations show a strong signature of the existence of a dark energy component with negative pressure. The most obvious candidate for this dark energy is the cosmological

Do Type Ia Supernovae Provide Direct Evidence for Past Deceleration of the Universe?

Observations of SN 1997ff at z ~ 1.7 favor the accelerating universe interpretation and provide some direct evidence that the universe was once decelerating. We show that the strength of this

Discovery of a supernova explosion at half the age of the Universe

The ultimate fate of the Universe, infinite expansion or a big crunch, can be determined by using the redshifts and distances of very distant supernovae to monitor changes in the expansion rate. We

Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant

We present spectral and photometric observations of 10 Type Ia supernovae (SNe Ia) in the redshift range 0.16 ≤ z ≤ 0.62. The luminosity distances of these objects are determined by methods that

Age Estimates of Globular Clusters in the Milky Way: Constraints on Cosmology

The 95% confidence level lower limit on the age of the Universe of 11.2 billion years means that the three fundamental observables in cosmology now independently support the case for a dark energy–dominated Universe.

Cosmological imprint of an energy component with general equation of state

We examine the possibility that a significant component of the energy density of the Universe has an equation of state different from that of matter, radiation, or cosmological constant ({Lambda} ).

Dark energy and the preposterous universe

A brief review is offered of the theoretical background concerning dark energy: what is required by observations, what sort of models are being considered, and how they fit into particle physics and

Type Ia Supernovae: Influence of the Initial Composition on the Nucleosynthesis, Light Curves, and Spectra and Consequences for the Determination of ΩM and Λ

The influence of the initial composition of the exploding white dwarf on the nucleosynthesis, light curves, and spectra of Type Ia supernovae has been studied in order to evaluate the size of

High-Redshift Supernovae in the Hubble Deep Field

Two supernovae detected in the Hubble Deep Field (HDF) using the original 1995 December epoch and data from a shorter (63,000 s in F814W) 1997 December visit with HST are discussed. The supernovae

The Expanding Universe

It is conjectured that the initial impulse which started the expansion may have arisen in the process of the condensation of the primeval chaotic gases into nebulæ, and some two million nebulae lie within a distance of 140,000,000 light-years.