MG13 - Talk detail |
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Participant |
van Oirschot, Pim | |||||||
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Institution |
Radboud University Nijmegen - Sint Thomashof 3 - Nijmegen - Nijmegen - Netherland | |||||||
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Session |
CM2 |
Accepted |
Yes |
Order |
7 |
Time |
15:50 - 16:05 | |
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Talk |
Oral abstract |
Title |
Another coincidence problem for $\Lambda$CDM | |||||
| Co-authors | Juliana Kwan and Geraint F. Lewis | |||||||
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Abstract |
Besides the well known coincidence problem for $\Lambda$CDM, we note that this concordance cosmological model contains another intriguing coincidence. In a universe with $\Omega_\Lambda = 0.73$, $\Omega_m = 0.27$, $w = -1$, and $h = 0.71$, and only with this choice of parameters, the time-averaged value of the deceleration parameter $\langle q \rangle$ over the age of the universe is remarkably close to zero today, and only today. Curious features like these in $\Lambda$CDM give rise to a number of alternate cosmologies being proposed to remove them, including models in which $\langle q \rangle = 0$ at all times. In this contribution we examine the validity of some of these alternate cosmologies. |
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