東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Theoretical and Observational Develo...

Chakraborty, Priyesh,

FindBook

Google Book

Amazon

博客來

Theoretical and Observational Developments of Inflation in Cosmology /

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Theoretical and Observational Developments of Inflation in Cosmology // Priyesh Chakraborty.
作者:	Chakraborty, Priyesh,
面頁冊數:	1 electronic resource (237 pages)
附註:	Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
Contained By:	Dissertations Abstracts International86-12B.
標題:	Physics. -
電子資源:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=32041047
ISBN:	9798280710054

Theoretical and Observational Developments of Inflation in Cosmology /
Chakraborty, Priyesh,

Theoretical and Observational Developments of Inflation in Cosmology /Priyesh Chakraborty. - 1 electronic resource (237 pages)

Source: Dissertations Abstracts International, Volume: 86-12, Section: B.

This thesis takes modest steps towards the goal of understanding the earliest period in the history of the universe-inflation. In the first leg, we focus on loop effects in de Sitter space. Therein we explain the physical meaning of anomalous dimensions and demonstrate how to compute them systematically for a broad class of scalar theories. Ultimately focusing on phenomenology, we highlight how otherwise undetectable light scalars can be visible in the cosmological collider signal of sufficiently heavy particles via its anomalous dimension. Moreover, we demonstrate how strong infrared effects in de Sitter lead to an enhancement of this quantity.Then, we focus on a special class of light scalars called axions, or compact scalar fields. Such particles are very theoretically well motivated as they can resolve several problems within the standard model of particle physics, one of which is the strong CP problem. Being field theoretic analogues of the quantum mechanical particle on a circle, we show that the quantization of these scalars crucially depends on their gauge constraint, or periodicity, unlike their behavior in flat-space. We further illustrate that taking care for their quantization, in addition, has phenomenological consequences which could aid their detection through a cosmological collider channel as well.We also point out that strong infrared effects qualitatively change their primordial signal from the naive expectation for a light scalar in inflation. In the process, we organize the primordial bispectrum generated by a broad class of higher-loop processes into a novel and useful form.In the second leg, we turn our focus towards the late universe. We specifically utilize a careful compression of the three-point correlation function, known as the skew-spectrum, in order to eﬀiciently extract the non- Gaussian information in late-universe tracers of the dark matter density. It is well known that tracers of the matter density in the late universe are highly non-Gaussian, and extracting this information using traditional means can quickly become highly expensive. The skew-spectra due to its compressed nature enables access to this non-Gaussian information with a dramatic improvement in speed. We first test the skew-spectra on simulations of lensing and galaxy cross-correlation analyses in order to estimate the galaxy bias parameters. Finally, we apply the skew-spectrum to the SDSS-BOSS galaxy catalog in order to measure f equil NL, finding no evidence of primordial non-Gaussianity.

English

ISBN: 9798280710054Subjects--Topical Terms:

516296
Physics.
Subjects--Index Terms:

Cosmology

Theoretical and Observational Developments of Inflation in Cosmology /
LDR:04018nmm a22004573i 4500 001 2433861
005 20250905091029.5
006 m o d
007 cr|nu||||||||
008 261011s2025 miu||||||m |||||||eng d
020 $a 9798280710054
035 $a (MiAaPQD)AAI32041047
035 $a AAI32041047
040 $a MiAaPQD $b eng $c MiAaPQD $e rda
100 1 $a Chakraborty, Priyesh, $e author. $0 (orcid)0000-0003-2844-9515 $3 3823634
245 1 0 $a Theoretical and Observational Developments of Inflation in Cosmology / $c Priyesh Chakraborty.
264 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2025
300 $a 1 electronic resource (237 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
500 $a Advisors: Dvorkin, Cora; Reece, Matthew Committee members: Kovac, John.
502 $b Ph.D. $c Harvard University $d 2025.
520 $a This thesis takes modest steps towards the goal of understanding the earliest period in the history of the universe-inflation. In the first leg, we focus on loop effects in de Sitter space. Therein we explain the physical meaning of anomalous dimensions and demonstrate how to compute them systematically for a broad class of scalar theories. Ultimately focusing on phenomenology, we highlight how otherwise undetectable light scalars can be visible in the cosmological collider signal of sufficiently heavy particles via its anomalous dimension. Moreover, we demonstrate how strong infrared effects in de Sitter lead to an enhancement of this quantity.Then, we focus on a special class of light scalars called axions, or compact scalar fields. Such particles are very theoretically well motivated as they can resolve several problems within the standard model of particle physics, one of which is the strong CP problem. Being field theoretic analogues of the quantum mechanical particle on a circle, we show that the quantization of these scalars crucially depends on their gauge constraint, or periodicity, unlike their behavior in flat-space. We further illustrate that taking care for their quantization, in addition, has phenomenological consequences which could aid their detection through a cosmological collider channel as well.We also point out that strong infrared effects qualitatively change their primordial signal from the naive expectation for a light scalar in inflation. In the process, we organize the primordial bispectrum generated by a broad class of higher-loop processes into a novel and useful form.In the second leg, we turn our focus towards the late universe. We specifically utilize a careful compression of the three-point correlation function, known as the skew-spectrum, in order to eﬀiciently extract the non- Gaussian information in late-universe tracers of the dark matter density. It is well known that tracers of the matter density in the late universe are highly non-Gaussian, and extracting this information using traditional means can quickly become highly expensive. The skew-spectra due to its compressed nature enables access to this non-Gaussian information with a dramatic improvement in speed. We first test the skew-spectra on simulations of lensing and galaxy cross-correlation analyses in order to estimate the galaxy bias parameters. Finally, we apply the skew-spectrum to the SDSS-BOSS galaxy catalog in order to measure f equil NL, finding no evidence of primordial non-Gaussianity.
546 $a English
590 $a School code: 0084
650 4 $a Physics. $3 516296
650 4 $a Astrophysics. $3 535904
650 4 $a Astronomy. $3 517668
650 4 $a Theoretical physics. $3 2144760
653 $a Cosmology
653 $a Skew-spectrum
653 $a Compact scalar fields
653 $a Dark matter
653 $a Non-Gaussian information
690 $a 0605
690 $a 0596
690 $a 0753
690 $a 0606
710 2 $a Harvard University. $b Physics. $e degree granting institution. $3 3765677
720 1 $a Dvorkin, Cora $e degree supervisor.
720 1 $a Reece, Matthew $e degree supervisor.
773 0 $t Dissertations Abstracts International $g 86-12B.
790 $a 0084
791 $a Ph.D.
792 $a 2025
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=32041047