Open AccessDark Energy and Cosmological Constant
Author(s) -
Louise Rebecca,
C. Sivaram,
Kenath Arun
Publication year - 2018
Publication title -
mapana journal of sciences
Language(s) - English
Resource type - Journals
ISSN - 0975-3303
DOI - 10.12723/mjs.44.3
Subject(s) - dark energy , physics , metric expansion of space , cosmological constant , phantom energy , de sitter universe , astrophysics , cosmic microwave background , big rip , universe , age of the universe , cosmology , particle horizon , flatness problem , zero energy universe , theoretical physics , astronomy , quantum mechanics , anisotropy
One of the unresolved problems in cosmology is that the measured mass density of the universe has revealed a value that was about 30% of the critical density. Since the universe is very nearly spatially flat, as is indicated by measurements of the cosmic microwave background, about 70% of the energy density of the universe was left unaccounted for. Another observation seems to be connected to this mystery. Generally one would expect the rate of expansion to slow down once the universe started expanding. The measurements of Type Ia supernovae have revealed that the expansion of the universe is actually accelerating. This accelerated expansion is attributed to the so-called dark energy (DE).Here we give a brief overview on the observational basis for DE hypothesis and how cosmological constant, initially proposed by Einstein to obtain a static universe, can play the role of dark energy.