权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Cosmic Strings from Simulation to Observation

宇宙弦从模拟到观测

基本信息

批准号：
1820902
负责人：
Ken Olum
金额：
$ 6万
依托单位：
Tufts University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1820902&HistoricalAwards=false
关键词：
Cosmic Strings Simulation Observation

项目摘要

This award funds research activities of Professor Ken D. Olum in the Tufts Institute of Cosmology at Tufts University.Cosmic strings are microscopically thin or even fundamental objects of cosmological length, which may or may not exist in our universe. Detection of cosmic strings would provide a window into fundamental physics at energies beyond the reach of any accelerator. Observation of a cosmic superstring network could provide a confirmation of the correctness of string theory. In addition to the bursts of gravitational waves that have recently been discovered by the LIGO and VIRGO observatories, there is likely to be a "background" of gravitational waves that is always present. Loops of cosmic strings are one of the sources that may contribute to this background, and observation of the background is an important way in which cosmic strings might be discovered. Professor Olum will study how the shape and motion of cosmic string loops changes during their lives and how this affects their emission of gravitational waves that become part of this background. If and when the gravitational wave background is discovered, this research will help us to distinguish whether it comes from cosmic strings or some other source, and to determine the properties of the cosmic string network if it is the source of the background. As such, research in this direction advances the national interest by further the development of basic sciences in the United States. Professor Olum will also involve graduate students in his work and thereby train future generations of research physicists. This work will also connect studies of the universe with studies of the fundamental laws of nature.More technically, Professor Olum will analyze gravitational back-reaction on cosmic string loops, to see how features such as cusps and kinks are modified by back-reaction. He will simulate realistic populations of cosmic string loops to see how their shapes evolve under back-reaction and compute the resulting gravitational emission spectrum for comparison with observations. He will also study the velocities acquired by loops in reaction to anisotropic gravitational wave emission, the so-called "rocket effect".This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这个奖项资助了塔夫茨大学塔夫茨宇宙学研究所肯·D·奥勒姆教授的研究活动。宇宙弦是微观上很细的物体，甚至是宇宙学长度的基本物体，它可能存在于我们的宇宙中，也可能不存在。对宇宙弦的探测将提供一扇了解基本物理的窗口，其能量超出任何加速器所能及的范围。对宇宙超弦网络的观察可以证实弦理论的正确性。除了LIGO和处女座天文台最近发现的引力波爆发外，很可能还有一个始终存在的引力波“背景”。宇宙弦的环路可能是造成这一背景的来源之一，而对背景的观察是发现宇宙弦的重要途径。奥勒姆教授将研究宇宙弦环的形状和运动在它们的生命过程中如何变化，以及这如何影响它们发出的引力波，引力波成为这一背景的一部分。如果引力波背景被发现，这项研究将有助于我们区分它是来自宇宙弦还是其他来源，并确定宇宙弦网络的性质，如果它是背景的来源。因此，这一方向的研究通过进一步促进美国基础科学的发展来促进国家利益。奥勒姆教授还将让研究生参与他的工作，从而培养未来几代研究物理学家。这项工作还将把对宇宙的研究与对自然基本定律的研究联系起来。更技术性的是，奥勒姆教授将分析宇宙弦环上的引力反反应，看看尖点和扭结等特征是如何被反反应修改的。他将模拟真实的宇宙弦环群体，以了解它们的形状在反反应下是如何演变的，并计算产生的引力发射光谱，以便与观测结果进行比较。他还将研究环路对各向异性引力波发射的反应速度，即所谓的“火箭效应”。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。