Quintessence in a quandary: prior dependence in dark energy models
The archetypal theory of dark energy is quintessence: a minimally coupled scalar field with a canonical kinetic energy and potential. By studying random potentials we show that quintessence imposes a restricted set of priors on the equation of state of dark energy. Focusing on the commonly-used para...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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American Physical Society
2014
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| _version_ | 1797060584095612928 |
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| author | Marsh, D Bull, P Ferreira, P Pontzen, A |
| author_facet | Marsh, D Bull, P Ferreira, P Pontzen, A |
| author_sort | Marsh, D |
| collection | OXFORD |
| description | The archetypal theory of dark energy is quintessence: a minimally coupled scalar field with a canonical kinetic energy and potential. By studying random potentials we show that quintessence imposes a restricted set of priors on the equation of state of dark energy. Focusing on the commonly-used parametrisation, $w(a)\approx w_0+w_a(1-a)$, we show that there is a natural scale and direction in the $(w_0, w_a)$ plane that distinguishes quintessence as a general framework. We calculate the expected information gain for a given survey and show that, because of the non-trivial prior information, it is a function of more than just the figure of merit. This allows us to make a quantitative case for novel survey strategies. We show that the scale of the prior sets target observational requirements for gaining significant information. This corresponds to a figure of merit FOM$\gtrsim 200$, a requirement that future galaxy redshift surveys will meet. |
| first_indexed | 2024-03-06T20:19:08Z |
| format | Journal article |
| id | oxford-uuid:2d334f51-cbad-46a1-8264-b98be86a9db1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:19:08Z |
| publishDate | 2014 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:2d334f51-cbad-46a1-8264-b98be86a9db12022-03-26T12:41:20ZQuintessence in a quandary: prior dependence in dark energy modelsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2d334f51-cbad-46a1-8264-b98be86a9db1EnglishSymplectic Elements at OxfordAmerican Physical Society2014Marsh, DBull, PFerreira, PPontzen, AThe archetypal theory of dark energy is quintessence: a minimally coupled scalar field with a canonical kinetic energy and potential. By studying random potentials we show that quintessence imposes a restricted set of priors on the equation of state of dark energy. Focusing on the commonly-used parametrisation, $w(a)\approx w_0+w_a(1-a)$, we show that there is a natural scale and direction in the $(w_0, w_a)$ plane that distinguishes quintessence as a general framework. We calculate the expected information gain for a given survey and show that, because of the non-trivial prior information, it is a function of more than just the figure of merit. This allows us to make a quantitative case for novel survey strategies. We show that the scale of the prior sets target observational requirements for gaining significant information. This corresponds to a figure of merit FOM$\gtrsim 200$, a requirement that future galaxy redshift surveys will meet. |
| spellingShingle | Marsh, D Bull, P Ferreira, P Pontzen, A Quintessence in a quandary: prior dependence in dark energy models |
| title | Quintessence in a quandary: prior dependence in dark energy models |
| title_full | Quintessence in a quandary: prior dependence in dark energy models |
| title_fullStr | Quintessence in a quandary: prior dependence in dark energy models |
| title_full_unstemmed | Quintessence in a quandary: prior dependence in dark energy models |
| title_short | Quintessence in a quandary: prior dependence in dark energy models |
| title_sort | quintessence in a quandary prior dependence in dark energy models |
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