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

RUI: WoU-MMA: Studies in Numerical Relativity

RUI：WoU-MMA：数值相对论研究

基本信息

批准号：
2010394
负责人：
Thomas Baumgarte
金额：
$ 24.47万
依托单位：
Bowdoin College
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2010394&HistoricalAwards=false
关键词：
RUI WoU MMA Studies Numerical

项目摘要

Einstein’s theory of general relativity describes all gravitational interactions in the universe, ranging from the force that pulls a falling apple to the Earth, to the expansion of the Universe itself. The equations of general relativity - called Einstein’s equations - are quite complicated and can be solved exactly, i.e. with pencil and paper, only under very special and unrealistic circumstances. Modeling more general scenarios requires computer simulations. Ongoing research efforts supported by this award aim at developing methods and approaches for such computer simulations, and to use these simulations to explore processes in relativistic astrophysics and general relativity. In the next few years this will include unresolved questions pertaining to the nature of general relativity — can arbitrarily small black holes form? — as well as effects of radiation in newly formed neutron stars and on black-hole accretion. Undergraduate students will participate in these activities, providing them with a “hands-on” research experience, and generating a research-enriched learning environment at Bowdoin College.The scientific goals of these research efforts include the development and implementation of numerical algorithms for the solution of Einstein's equations of general relativity, as well as their application in the numerical modeling of relativistic objects, in particular neutron stars and black holes. In the next funding period these activities will focus on projects in two main areas, namely critical phenomena in the gravitational collapse to black holes, and dynamical effects of radiation. With regard to the former, the focus will be on situations in which the critical solution cannot be spherically symmetric. Building on experience and insights from previous work on critical collapse, these phenomena will be explored for the collapse of gravitational waves in vacuum spacetimes, an important problem that remains poorly understood even 25 years after it was first tackled. With regard to the latter, an approximate treatment of radiation transfer will be implemented and used to explore several scenarios in which radiation may play an important dynamical role. Examples include the evolution of supermassive stars up to the onset of radial instability, possible non-axisymmetric instabilities triggered by cooling in proto-neutron stars, and an exploration of super-Eddington flows in accretion onto black holes.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.

爱因斯坦的广义相对论描述了宇宙中所有的引力相互作用，从将掉落的苹果拉向地球的力，到宇宙本身的膨胀。广义相对论的方程--爱因斯坦方程--相当复杂，只有在非常特殊和不现实的情况下，才能用铅笔和纸精确地解出来。模拟更一般的场景需要计算机模拟。该奖项支持的正在进行的研究工作旨在开发此类计算机模拟的方法和途径，并使用这些模拟来探索相对论天体物理学和广义相对论中的过程。在接下来的几年里，这将包括与广义相对论的性质有关的未解决的问题-任意小的黑洞可以形成吗？- 以及辐射对新形成的中子星和黑洞吸积的影响。本科生将参与这些活动，为他们提供“动手”的研究经验，并在鲍登学院创造一个研究丰富的学习环境。这些研究工作的科学目标包括发展和实施爱因斯坦广义相对论方程的数值算法，以及它们在相对论物体数值建模中的应用，特别是中子星和黑洞。在下一个资助期内，这些活动将集中在两个主要领域的项目上，即引力坍缩到黑洞的关键现象和辐射的动力学效应。关于前者，重点将放在临界解不能是球对称的情况。基于以前临界坍缩工作的经验和见解，这些现象将被探索为真空时空中引力波的坍缩，这是一个重要的问题，即使在首次解决后25年仍然知之甚少。关于后者，将对辐射转移进行近似处理，并用于探讨辐射可能发挥重要动力作用的几种情况。例子包括超大质量恒星的演化到径向不稳定性的开始，可能的非轴对称不稳定性引发的冷却在原中子星，并探索超爱丁顿流吸积到黑洞。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。