TY - JOUR
T1 - Analysing dissipative effects in the ΛcDM model
AU - Cruz, Norman
AU - González, Esteban
AU - Lepe, Samuel
AU - Gómez, DIego Sáez Chillón
N1 - Funding Information:
is funded by the grant No. IT956-16 (Basque Government, Spain) and by MINECO (Spain), project FIS2016-76363-P.
Funding Information:
N. C. acknowledges the support of CONICYT (Chile) through the grant Fondecyt N◦ 1140238. E.G. is supported by the CONICYT-PCHA/Doctorado Nacional/2016-21160331. D.S-C.G.
Funding Information:
N. C. acknowledges the support of CONICYT (Chile) through the grant Fondecyt N? 1140238. E.G. is supported by the CONICYT-PCHA/Doctorado Nacional/2016-21160331. D.S-C.G. is funded by the grant No. IT956-16 (Basque Government, Spain) and by MINECO (Spain), project FIS2016-76363-P.
Publisher Copyright:
© 2018 IOP Publishing Ltd and Sissa Medialab.
PY - 2018/12/11
Y1 - 2018/12/11
N2 - In the present paper, the effects of viscous dark matter are analysed within the ΛCDM model. Here we consider bulk viscosity through the Israel-Stewart theory approach, leading to an effective pressure term in the continuity equation that accomplishes for the dissipative effects of the dark matter fluid. Then, the corresponding equation for viscosity is solved and a general equation for the Hubble parameter is obtained with the presence of a cosmological constant. The existence of de Sitter solutions is discussed, where a wider range of solutions is found in comparison to the ΛCDM model. Also the conditions for the near thermodynamical equilibrium of the fluid is analysed. Finally, a qualitative analysis provides some constraints on the model by using Supernovae Ia data which reveals the possible importance of causal thermodynamics in cosmology.
AB - In the present paper, the effects of viscous dark matter are analysed within the ΛCDM model. Here we consider bulk viscosity through the Israel-Stewart theory approach, leading to an effective pressure term in the continuity equation that accomplishes for the dissipative effects of the dark matter fluid. Then, the corresponding equation for viscosity is solved and a general equation for the Hubble parameter is obtained with the presence of a cosmological constant. The existence of de Sitter solutions is discussed, where a wider range of solutions is found in comparison to the ΛCDM model. Also the conditions for the near thermodynamical equilibrium of the fluid is analysed. Finally, a qualitative analysis provides some constraints on the model by using Supernovae Ia data which reveals the possible importance of causal thermodynamics in cosmology.
KW - dark energy theory
KW - dark matter theory
UR - http://www.scopus.com/inward/record.url?scp=85059893755&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2018/12/017
DO - 10.1088/1475-7516/2018/12/017
M3 - Article
AN - SCOPUS:85059893755
VL - 2018
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 12
M1 - 017
ER -