H.V. Ragavendra, Anjan Kumar Sarkar and Shiv K. Sethi
{"title":"利用宇宙学数据集制约超慢速滚动膨胀","authors":"H.V. Ragavendra, Anjan Kumar Sarkar and Shiv K. Sethi","doi":"10.1088/1475-7516/2024/07/088","DOIUrl":null,"url":null,"abstract":"In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during inflationary epoch. We constrain excess power over small scales within the framework of such models using cosmological datasets, particularly of CMB anisotropies and Lyman-α. We parameterize the USR phase in terms of the e-fold at the onset of USR (counted from the end of inflation) N̅1 and the duration of USR phase Δ N. The former dictates the scale of enhancement in the primordial power spectrum, while the latter determines the amplitude of such an enhancement. From a joint dataset of CMB and galaxy surveys, we obtain N̅1 ≲ 45 with no bound on Δ N. This in turn implies that the scales over which the power spectrum can deviate significantly from the nearly scale invariant behavior of a typical slow-roll model is k ≳1 Mpc-1. On the other hand, the Lyman-α data is sensitive to baryonic power spectrum along the line of sight. We consider a semi-analytic theoretical method and high spectral-resolution Lyman-α data to constrain the model. The Lyman-α data limits both the USR parameters: N̅1 ≲ 41 and Δ N ≲ 0.4. This constrains the amplitude of the power spectrum enhancement to be less than a factor of hundred over scales 1 ≲ k/ Mpc-1≲ 100, thereby considerably improving the constraint on power over these scales as compared to the bounds arrived at from CMB spectral distortion.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Constraining ultra slow roll inflation using cosmological datasets\",\"authors\":\"H.V. Ragavendra, Anjan Kumar Sarkar and Shiv K. Sethi\",\"doi\":\"10.1088/1475-7516/2024/07/088\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during inflationary epoch. We constrain excess power over small scales within the framework of such models using cosmological datasets, particularly of CMB anisotropies and Lyman-α. We parameterize the USR phase in terms of the e-fold at the onset of USR (counted from the end of inflation) N̅1 and the duration of USR phase Δ N. The former dictates the scale of enhancement in the primordial power spectrum, while the latter determines the amplitude of such an enhancement. From a joint dataset of CMB and galaxy surveys, we obtain N̅1 ≲ 45 with no bound on Δ N. This in turn implies that the scales over which the power spectrum can deviate significantly from the nearly scale invariant behavior of a typical slow-roll model is k ≳1 Mpc-1. On the other hand, the Lyman-α data is sensitive to baryonic power spectrum along the line of sight. We consider a semi-analytic theoretical method and high spectral-resolution Lyman-α data to constrain the model. The Lyman-α data limits both the USR parameters: N̅1 ≲ 41 and Δ N ≲ 0.4. This constrains the amplitude of the power spectrum enhancement to be less than a factor of hundred over scales 1 ≲ k/ Mpc-1≲ 100, thereby considerably improving the constraint on power over these scales as compared to the bounds arrived at from CMB spectral distortion.\",\"PeriodicalId\":15445,\"journal\":{\"name\":\"Journal of Cosmology and Astroparticle Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2024-07-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Cosmology and Astroparticle Physics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1088/1475-7516/2024/07/088\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Cosmology and Astroparticle Physics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1475-7516/2024/07/088","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Constraining ultra slow roll inflation using cosmological datasets
In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during inflationary epoch. We constrain excess power over small scales within the framework of such models using cosmological datasets, particularly of CMB anisotropies and Lyman-α. We parameterize the USR phase in terms of the e-fold at the onset of USR (counted from the end of inflation) N̅1 and the duration of USR phase Δ N. The former dictates the scale of enhancement in the primordial power spectrum, while the latter determines the amplitude of such an enhancement. From a joint dataset of CMB and galaxy surveys, we obtain N̅1 ≲ 45 with no bound on Δ N. This in turn implies that the scales over which the power spectrum can deviate significantly from the nearly scale invariant behavior of a typical slow-roll model is k ≳1 Mpc-1. On the other hand, the Lyman-α data is sensitive to baryonic power spectrum along the line of sight. We consider a semi-analytic theoretical method and high spectral-resolution Lyman-α data to constrain the model. The Lyman-α data limits both the USR parameters: N̅1 ≲ 41 and Δ N ≲ 0.4. This constrains the amplitude of the power spectrum enhancement to be less than a factor of hundred over scales 1 ≲ k/ Mpc-1≲ 100, thereby considerably improving the constraint on power over these scales as compared to the bounds arrived at from CMB spectral distortion.
期刊介绍:
Journal of Cosmology and Astroparticle Physics (JCAP) encompasses theoretical, observational and experimental areas as well as computation and simulation. The journal covers the latest developments in the theory of all fundamental interactions and their cosmological implications (e.g. M-theory and cosmology, brane cosmology). JCAP''s coverage also includes topics such as formation, dynamics and clustering of galaxies, pre-galactic star formation, x-ray astronomy, radio astronomy, gravitational lensing, active galactic nuclei, intergalactic and interstellar matter.