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Galaxy Surveys as Probes of the Primordial Universe Opportunities and Challenges
Galaxy Surveys as Probes of the Primordial Universe Opportunities and Challenges
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152123
- ISBN
- 9798342728539
- DDC
- 530
- 서명/저자
- Galaxy Surveys as Probes of the Primordial Universe Opportunities and Challenges
- 발행사항
- [Sl] : State University of New York at Stony Brook, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 110 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-05, Section: B.
- 주기사항
- Advisor: Loverde, Marilena;Essig, Roven.
- 학위논문주기
- Thesis (Ph.D.)--State University of New York at Stony Brook, 2024.
- 초록/해제
- 요약Observations of the Large-Scale Structure (LSS) of the universe have emerged as a powerful probe of the physics of cosmic inflation. Upcoming LSS surveys can be particularly useful in constraining primordial non-Gaussianity (PnG) which is an important signature of all but the simplest models of cosmic inflation. Constraints on PnG can potentially distinguish between different inflationary models and provide invaluable insight into the generation of primordial fluctuations which seed the rich structure of the universe. On the other hand, the non-linear nature of structure-formation makes it harder to fully exploit the data collected by LSS surveys.A robust detection of a non-trivial local PnG (LPnG) implies the existence of an additional massless degree of freedom during inflation. LPnG is particularly amenable to detection by large-scale galaxy surveys as its observable signal peaks at the largest scales, where galaxy clustering can be adequately described by a linear/perturbative bias expansion and is modulated predominantly by inflationary effects. However, post-inflationary effects can also modulate galaxy clustering on the largest observable scales, and serve as important theoretical systematics. Although sub-dominant to their inflationary counterparts, they can significantly bias constraints on LPnG obtained from large-scale galaxy surveys.In this dissertation, we explore the potential of upcoming large-scale galaxy surveys to constrain LPnG. We begin by exploring the constraining power of the upcoming SPHEREx all-sky survey in constraining LPnG beyond the simplest scenario of a non-trivial primordial bispectrum. We obtain a Markov Chain Monte Carlo (MCMC) forecast to assess how well the SPHEREx all-sky survey can constrain LPnG parameters fNL, gNL and τNL from galaxy power spectra. We then proceed to investigate the effect of some post-inflationary systematics that can affect constraints on LPnG. Using Separate Universe simulations, we model the large-scale modulation of galaxy clustering by the free-streaming of light relics. We then analyse how the free-streaming of light relics and fluctuations in the background of ionising radiation can bias forecast constraints on fNL obtained from galaxy power spectra. In this way, we quantify their importance as theoretical systematics relevant for large-scale galaxy surveys seeking to constrain LPnG.
- 일반주제명
- Physics
- 일반주제명
- Theoretical physics
- 일반주제명
- Astronomy
- 일반주제명
- Astrophysics
- 기타저자
- State University of New York at Stony Brook Physics
- 기본자료저록
- Dissertations Abstracts International. 86-05B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■006m o d
■007cr#unu||||||||
■020 ▼a9798342728539
■035 ▼a(MiAaPQ)AAI31481915
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aShiveshwarkar, Charuhas Waman.
■24510▼aGalaxy Surveys as Probes of the Primordial Universe Opportunities and Challenges
■260 ▼a[Sl]▼bState University of New York at Stony Brook▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a110 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-05, Section: B.
■500 ▼aAdvisor: Loverde, Marilena;Essig, Roven.
■5021 ▼aThesis (Ph.D.)--State University of New York at Stony Brook, 2024.
■520 ▼aObservations of the Large-Scale Structure (LSS) of the universe have emerged as a powerful probe of the physics of cosmic inflation. Upcoming LSS surveys can be particularly useful in constraining primordial non-Gaussianity (PnG) which is an important signature of all but the simplest models of cosmic inflation. Constraints on PnG can potentially distinguish between different inflationary models and provide invaluable insight into the generation of primordial fluctuations which seed the rich structure of the universe. On the other hand, the non-linear nature of structure-formation makes it harder to fully exploit the data collected by LSS surveys.A robust detection of a non-trivial local PnG (LPnG) implies the existence of an additional massless degree of freedom during inflation. LPnG is particularly amenable to detection by large-scale galaxy surveys as its observable signal peaks at the largest scales, where galaxy clustering can be adequately described by a linear/perturbative bias expansion and is modulated predominantly by inflationary effects. However, post-inflationary effects can also modulate galaxy clustering on the largest observable scales, and serve as important theoretical systematics. Although sub-dominant to their inflationary counterparts, they can significantly bias constraints on LPnG obtained from large-scale galaxy surveys.In this dissertation, we explore the potential of upcoming large-scale galaxy surveys to constrain LPnG. We begin by exploring the constraining power of the upcoming SPHEREx all-sky survey in constraining LPnG beyond the simplest scenario of a non-trivial primordial bispectrum. We obtain a Markov Chain Monte Carlo (MCMC) forecast to assess how well the SPHEREx all-sky survey can constrain LPnG parameters fNL, gNL and τNL from galaxy power spectra. We then proceed to investigate the effect of some post-inflationary systematics that can affect constraints on LPnG. Using Separate Universe simulations, we model the large-scale modulation of galaxy clustering by the free-streaming of light relics. We then analyse how the free-streaming of light relics and fluctuations in the background of ionising radiation can bias forecast constraints on fNL obtained from galaxy power spectra. In this way, we quantify their importance as theoretical systematics relevant for large-scale galaxy surveys seeking to constrain LPnG.
■590 ▼aSchool code: 0771.
■650 4▼aPhysics
■650 4▼aTheoretical physics
■650 4▼aAstronomy
■650 4▼aAstrophysics
■653 ▼aCosmological forecasts
■653 ▼aInflationary cosmology
■653 ▼aLarge-Scale Structure
■653 ▼aPrimordial non-Gaussianity
■690 ▼a0605
■690 ▼a0753
■690 ▼a0606
■690 ▼a0596
■71020▼aState University of New York at Stony Brook▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g86-05B.
■790 ▼a0771
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17163006▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.


