About this Research Topic
The discovery in 1998 that the expansion of the universe is accelerating instead of slowing down (Nobel Prize for Physics in 2011), driven by a previously unknown component labeled dark energy, has opened a new chapter in cosmology and also in fundamental physics.
Dark energy appears to be the dominant component in the mass-energy budget of the universe, but its nature remains completely unknown. Theoretical attempts to explain dark energy range from departures from the predictions of general relativity on large scales to new fields acting on a cosmological scale to the cosmological constant. Considerable effort is devoted, on the other hand, to the observational exploration of dark energy, based on diverse approaches (supernovae, baryon acoustic oscillations, weak lensing, formation of large scale structure, cosmic microwave background radiation) and mobilizing all kinds of resources, both on the ground and in upcoming space missions.
Moreover, the recent detections of gravitational wave (GW) signals by the LIGO and VIRGO collaborations have opened an entire new window in the universe. GW astronomy will greatly help understand the nature of dark energy by measuring the distance of the sources and how much space has expanded during the time the wave was travelling towards us.
GW events through the measurement at which the GWs move in relation to the speed of light allow to discard or confirm modified gravity models, which depart from general relativity and produce acceleration of the universe without invoking a cosmological constant. This has been done recently with GW170817 which has been able to discard a large variety of modified gravity proposals.
Frontiers in Astronomy and Space Sciences aims to play an important role in this fundamental and rapidly growing area of research, through the publication of relevant articles, theoretical and observational.
This Research Topic aims to gather contributions on the latest developments in understanding the nature of dark energy from both a theoretical and an observational point of view. We welcome both state-of-the-art reviews and original articles, as well as perspectives on this exciting field of research.
Keywords: Dark energy, cosmology, modified gravity, cosmological constant
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.