MG13 - Talk detail |
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Participant |
Merafina, Marco | |||||||
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Institution |
University of Rome "La Sapienza" - Physics Department - Piazzale Aldo Moro, 2 - Rome - - Italy | |||||||
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Session |
CM2 |
Accepted |
Yes |
Order |
5 |
Time |
20' | |
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Talk |
Oral abstract |
Title |
Polytropic equilibrium models with non-zero cosmological constant | |||||
| Co-authors | Gennady S. BISNOVATYI-KOGAN, Sergey O. TARASOV | |||||||
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Abstract |
We investigate the gravitational equilibrium and stability of polytropic spheres in presence of a non-zero cosmological constant by solving the equations of gravitational equilibrium with a polytropic equation of state of the matter and non-zero cosmological constant. We construct series of solutions with a fixed value cosmological constant. For each value of n, the non-dimensional equation of equilibrium has a family of solutions, instead of the unique solution of the Lane-Emden equation in absence of cosmological constant. The equilibrium state exists only for central densities larger than a critical value. Also, we investigate the stability of equilibrium solutions and show that dark energy reduces the dynamic stability of the configuration. |
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