Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations
We investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (...
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doaj-d11125b8056b4413855694e51fdf762e2020-11-24T22:54:18ZengHindawi LimitedAdvances in Astronomy1687-79691687-79772012-01-01201210.1155/2012/528243528243Constraints on a Vacuum Energy from Both SNIa and CMB Temperature ObservationsRiou Nakamura0E. P. Berni Ann Thushari1Mikio Ikeda2Masa-Aki Hashimoto3Department of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka City 812-8581, JapanDepartment of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka City 812-8581, JapanDepartment of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka City 812-8581, JapanDepartment of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka City 812-8581, JapanWe investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (SNIa) by Union-2 compilation and the cosmic microwave background (CMB) temperature at the range of the redshift 0.01<z<3. From SNIa, we find that the effects of a decaying vacuum energy on the cosmic expansion rate should be very small but could be possible for z<1.5. On the other hand, we obtain the severe constraints for parameters from the CMB temperature observations. Although the temperature can be still lower than the case of the standard cosmological model, it should only affect the thermal evolution at the early epoch.http://dx.doi.org/10.1155/2012/528243 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Riou Nakamura E. P. Berni Ann Thushari Mikio Ikeda Masa-Aki Hashimoto |
spellingShingle |
Riou Nakamura E. P. Berni Ann Thushari Mikio Ikeda Masa-Aki Hashimoto Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations Advances in Astronomy |
author_facet |
Riou Nakamura E. P. Berni Ann Thushari Mikio Ikeda Masa-Aki Hashimoto |
author_sort |
Riou Nakamura |
title |
Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations |
title_short |
Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations |
title_full |
Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations |
title_fullStr |
Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations |
title_full_unstemmed |
Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations |
title_sort |
constraints on a vacuum energy from both snia and cmb temperature observations |
publisher |
Hindawi Limited |
series |
Advances in Astronomy |
issn |
1687-7969 1687-7977 |
publishDate |
2012-01-01 |
description |
We investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (SNIa) by Union-2 compilation and the cosmic microwave background (CMB) temperature at the range of the redshift 0.01<z<3. From SNIa, we find that the effects of a decaying vacuum energy on the cosmic expansion rate should be very small but could be possible for z<1.5. On the other hand, we obtain the severe constraints for parameters from the CMB temperature observations. Although the temperature can be still lower than the case of the standard cosmological model, it should only affect the thermal evolution at the early epoch. |
url |
http://dx.doi.org/10.1155/2012/528243 |
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AT riounakamura constraintsonavacuumenergyfrombothsniaandcmbtemperatureobservations AT epberniannthushari constraintsonavacuumenergyfrombothsniaandcmbtemperatureobservations AT mikioikeda constraintsonavacuumenergyfrombothsniaandcmbtemperatureobservations AT masaakihashimoto constraintsonavacuumenergyfrombothsniaandcmbtemperatureobservations |
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