Observational Signatures of Cosmic Strings

宇宙弦的观测特征

• 批准号: 2111738
• 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: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2111738&HistoricalAwards=false
• 关键词: Observational; Signatures; Cosmic; Strings

This award funds some of the research activities of Professor Ken D. Olum 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, which is our current best theory for unifying the physics of gravity with the physics that governs the subatomic world. The best hope for discovering a cosmic string network is through observation of gravitational waves. The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has detected a signal that is likely be the first sign of a gravitational wave background formed by many sources throughout the universe. These sources could be pairs of giant black holes in the centers of galaxies, but they could also be cosmic string loops. Professor Olum will study the gravitational waves that would be emitted by cosmic strings and compare them with current and forthcoming NANOGrav observations. Professor Olum will also involve graduate students in this work and thereby train future generations of research physicists --- an activity which is in the national interest. The work will further connect studies of the universe with studies of the fundamental laws of nature.More technically, Professor Olum will simulate the evolution of cosmic string loops under the effects of gravitational self-interaction to see how their shapes and their gravitational wave spectra change over time. He will use a realistic population of cosmic string loops taken from his previous cosmic string network simulations. By combining the spectra from these loops, he will generate a gravitational wave background spectrum to be expected from cosmic strings and compare it with pulsar timing observations from the NANOGrav collaboration, of which he is a member. He will also study the velocities acquired by loops in reaction to anisotropic gravitational wave emission, the so-called "rocket effect", which is important for determining the degree of clustering of cosmic string loops in galaxies, and thus their potential observability.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.

该奖项资助了Ken D教授的一些研究活动。宇宙弦是非常细的，甚至是宇宙长度的基本物体，它可能存在于我们的宇宙中，也可能不存在。宇宙弦的探测将提供一个窗口，让我们了解任何加速器都无法到达的能量下的基础物理学。对宇宙超弦网络的观测可以证实弦理论的正确性，弦理论是我们目前统一引力物理学和支配亚原子世界的物理学的最佳理论。 发现宇宙弦网络的最大希望是通过观测引力波。 北美纳赫兹引力波天文台（NANOGrav）探测到了一个信号，这可能是整个宇宙中许多源形成的引力波背景的第一个迹象。 这些来源可能是星系中心的一对巨大黑洞，但它们也可能是宇宙弦环。 Olum教授将研究宇宙弦发出的引力波，并将其与当前和即将到来的NANOGrav观测进行比较。 奥伦教授还将让研究生参与这项工作，从而培养未来几代的研究物理学家-这是一项符合国家利益的活动。 这项工作将进一步将宇宙研究与自然基本定律的研究联系起来。更技术性的是，Olum教授将模拟宇宙弦环在引力自相互作用作用作用下的演化，看看它们的形状和引力波谱如何随时间变化。 他将使用从他以前的宇宙弦网络模拟中获得的宇宙弦环的现实人口。 通过结合这些环的光谱，他将产生一个预期来自宇宙弦的引力波背景光谱，并将其与NANOGrav合作的脉冲星计时观测进行比较，他是其中的一员。 他还将研究各向异性引力波发射的反应，即所谓的“火箭效应”，这对确定星系中宇宙弦环的聚集程度以及潜在的可观测性非常重要。该奖项反映了NSF的法定使命，并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，被认为值得支持。

项目成果

The NANOGrav 15 yr Data Set: Search for Signals from New Physics

• DOI: 10.3847/2041-8213/acdc91
• 发表时间: 2023-06
• 期刊: The Astrophysical Journal Letters
• 作者: A. Afzal;G. Agazie;A. Anumarlapudi;A. Archibald;Z. Arzoumanian;P. Baker;B. B'ecsy;J. Blanco-Pillado;L. Blecha;K. Boddy;A. Brazier;P. Brook;S. Burke-Spolaor;R. Burnette;R. Case;M. Charisi;S. Chatterjee;K. Chatziioannou;B. Cheeseboro;Siyuan Chen;T. Cohen;J. Cordes;N. Cornish;F. Crawford;H. Cromartie;K. Crowter;C. Cutler;M. DeCesar;D. DeGan;P. Demorest;Heling Deng;T. Dolch;B. Drachler;R. V. Eckardstein;E. Ferrara;W. Fiore;E. Fonseca;G. Freedman;N. Garver-Daniels;P. Gentile;K. A. Gersbach;J. Glaser;D. Good;Lydia Guertin;K. Gultekin;J. Hazboun;S. Hourihane;K. Islo;R. Jennings;A. Johnson;Megan L. Jones;A. Kaiser;D. Kaplan;L. Kelley;M. Kerr;J. Key;N. Laal;M. Lam;W. Lamb;T. Lazio;Vincent S. H. Lee;N. Lewandowska;Rafael R. Lino dos Santos;T. Littenberg;Tianyu Liu;D. Lorimer;Jing Luo;R. Lynch;Chung-Pei Ma;D. Madison;A. McEwen;J. McKee;M. Mclaughlin;N. McMann;B. W. Meyers;P. Meyers;C. Mingarelli;A. Mitridate;J. Nay;P. Natarajan;C. Ng;D. Nice;S. Ocker;K. Olum;T. Pennucci;B. Perera;P. Petrov;N. Pol;H. Radovan;S. Ransom;P. Ray;J. Romano;S. C. Sardesai;A. Schmiedekamp;C. Schmiedekamp;K. Schmitz;T. Schroder;L. Schult;B. Shapiro-Albert;X. Siemens;J. Simon;M. Siwek;I. Stairs;D. Stinebring;K. Stovall;Peter Stratmann;Jerry P. Sun;A. Susobhanan;J. Swiggum;Jacob M. Taylor;S. Taylor;T. Trickle;J. E. Turner;C. Unal;M. Vallisneri;Sonali Verma;S. Vigeland;H. Wahl;Qiaohong Wang;C. Witt;Davis Wright;O. Young;K. Zurek

Nambu-Goto dynamics of field theory cosmic string loops

场论宇宙弦环的南部-后岛动力学

• DOI: 10.1088/1475-7516/2023/05/035
• 发表时间: 2023
• 期刊: Journal of Cosmology and Astroparticle Physics
• 影响因子: 6.4
• 作者: Blanco-Pillado, Jose J.;Jiménez-Aguilar, Daniel;Lizarraga, Joanes;Lopez-Eiguren, Asier;Olum, Ken D.;Urio, Ander;Urrestilla, Jon
• 通讯作者: Urrestilla, Jon

The NANOGrav Search for Signals from New Physics: MCMC chains

NANOGrav 从新物理中寻找信号：MCMC 链

• DOI: 10.5281/zenodo.8083620
• 发表时间: 2023
• 期刊: Zenodo
• 作者: NANOGrav, The Collaboration