Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation
Recent analyses of cosmic microwave background surveys have revealed hints that there may be a non-trivial running of the running of the spectral index. If future experiments were to confirm these hints, it would prove a powerful discriminator of inflationary models, ruling out simple single field mode...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-03-01
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| Series: | Universe |
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| Online Access: | http://www.mdpi.com/2218-1997/3/1/17 |
| _version_ | 1798040673672232960 |
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| author | Chris Longden |
| author_facet | Chris Longden |
| author_sort | Chris Longden |
| collection | DOAJ |
| description | Recent analyses of cosmic microwave background surveys have revealed hints that there may be a non-trivial running of the running of the spectral index. If future experiments were to confirm these hints, it would prove a powerful discriminator of inflationary models, ruling out simple single field models. We discuss how isocurvature perturbations in multi-field models can be invoked to generate large runnings in a non-standard hierarchy, and find that a minimal model capable of practically realising this would be a two-field model with a non-canonical kinetic structure. We also consider alternative scenarios such as variable speed-of-light models and canonical quantum gravity effects and their implications for runnings of the spectral index. |
| first_indexed | 2024-04-11T22:10:49Z |
| format | Article |
| id | doaj.art-7c3687c62a3642f8a4e95e1ea74e80a0 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-04-11T22:10:49Z |
| publishDate | 2017-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-7c3687c62a3642f8a4e95e1ea74e80a02022-12-22T04:00:34ZengMDPI AGUniverse2218-19972017-03-01311710.3390/universe3010017universe3010017Non-Standard Hierarchies of the Runnings of the Spectral Index in InflationChris Longden0School of Mathematics and Statistics, University of Sheffield, Sheffield S10 2TN, UKRecent analyses of cosmic microwave background surveys have revealed hints that there may be a non-trivial running of the running of the spectral index. If future experiments were to confirm these hints, it would prove a powerful discriminator of inflationary models, ruling out simple single field models. We discuss how isocurvature perturbations in multi-field models can be invoked to generate large runnings in a non-standard hierarchy, and find that a minimal model capable of practically realising this would be a two-field model with a non-canonical kinetic structure. We also consider alternative scenarios such as variable speed-of-light models and canonical quantum gravity effects and their implications for runnings of the spectral index.http://www.mdpi.com/2218-1997/3/1/17early universe cosmologytesting inflationmulti-field inflation |
| spellingShingle | Chris Longden Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation Universe early universe cosmology testing inflation multi-field inflation |
| title | Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation |
| title_full | Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation |
| title_fullStr | Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation |
| title_full_unstemmed | Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation |
| title_short | Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation |
| title_sort | non standard hierarchies of the runnings of the spectral index in inflation |
| topic | early universe cosmology testing inflation multi-field inflation |
| url | http://www.mdpi.com/2218-1997/3/1/17 |
| work_keys_str_mv | AT chrislongden nonstandardhierarchiesoftherunningsofthespectralindexininflation |