초록

Abstract ▼

연구개발 목표 및 내용
최종 목표
General relativity breaks down at an extreme high energy as in the early Universe, and is expected to be superseded by quantum gravity, such as superstring theory. Superstring theory includes Einstein’s general relativity as a low energy effective theory, but it also include

연구개발 목표 및 내용
최종 목표
General relativity breaks down at an extreme high energy as in the early Universe, and is expected to be superseded by quantum gravity, such as superstring theory. Superstring theory includes Einstein’s general relativity as a low energy effective theory, but it also includes higher curvature correction terms. Studying the effects of such terms is important for understanding the phenomenology of the early Universe and also provides testbeds for superstring models. The purpose of this research project is to investigate the string theoretical corrections to primordial gravitational waves that are theoretically expected from the early Universe, and make prediction for the future observations and experiments. Theoretical study of gravitational waves is very active after the direct detection of the gravitational waves by LIGO in 2015; thus our project is very timely. Also, our study will support future experimental projects from the theoretical side. In this project, we investigate higher curvature terms from generalised Calabi-Yau compactification which is considered as a phenomenologically attractive string theoretical model.

전체 내용
In the near future, gravitational waves are expected to provide a new window to study the early Universe. Detection of gravitational waves can be made either indirectly, e.g. in the CMB B-mode, or directly, by interferometric detectors such as the LIGO and the LISA. Direct and indirect detection of gravitational waves target very different frequencies. Indirect signals are encoded in the CMB, and their frequencies are naturally in the low range, determined by the horizon-exit of the CMB scale corresponding to 50-60 e-folds before the end of inflation. In contrast, the frequencies targeted in direct detection is determined by the arm lengths of interferometers; in the cases of BBO or DECIGO, the frequencies typically correspond to 10-20 e-folds prior to reheating. Thus direct signals of primordial gravitational waves, if detected, would elucidate the physics of later stages of inflation which is not accessible by other cosmological signals.

연구개발성과
In the course of study we realized the importance of primorial blakc holes thus incorporated the study of it in the study of gravitational waves.

연구개발성과 활용계획 및 기대 효과
We have set some foundation of the theoretical study on gravitaitonal waves and primordial black holes based on string theoretical higher curvature gvavity. The results will be interesting for futrure observational develpements as well as theoretical study.

(source : 요약문 2p)

목차 Contents

• COVER ... 1
• 요 약 문 ... 2
• 목차 ... 4
• 1. 연구개발과제의 개요 ... 5
• (1) Study of higher curvature terms from generalized Calabi-Yau manifold ... 6
• (2) Study of the unitarity problem using the scattering amplitude theory ... 6
• (3) Phenomenology of higher curvature terms ... 6
• 2. 연구개발과제의 수행 과정 및 수행 내용 ... 7
• 3. 연구개발과제의 수행 결과 및 목표 달성 정도 ... 7
• 1) 연구수행 결과 ... 8
• 4. 연구개발성과의 관련 분야에 대한 기여 정도 ... 8
• 5. 연구개발성과의 관리 및 활용 계획 ... 9
• 6. 참고문헌 ... 9
• End of Page ... 9