EAPSI: Computer simulations of dark matter with an altered gravitational attraction

EAPSI：对改变引力的暗物质进行计算机模拟

• 批准号: 1415111
• 负责人: Kevin Croker
• 金额: $ 0.51万
• 依托单位: Croker Kevin A
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1415111&HistoricalAwards=false
• 关键词: EAPSI; Computer; simulations; dark; matter

Physicists and astronomers have conclusively determined that a large percent of the matter within our universe is dark and of unknown composition. While computer simulations which model this dark matter over billions of years produce a universe in agreement with observation at sizes larger than galaxies, disagreement with data remains at the size of individual galaxies. Recent extensions to Einstein's description of gravity have produced a new type of dark matter which agrees with data at the size of individual galaxies. Through supercomputer simulations, in collaboration with Dr. Naoki Yoshida jointly at University of Tokyo and Kavli Institute on the Physics and Mathematics of the Universe (IPMU) in Japan, this study will investigate whether this form of dark matter can also produce a universe in agreement with data at sizes larger than galaxies. This study has the potential to resolve a long-standing disagreement between astronomers and astrophysicists, and could point toward more fruitful extensions to Einstein's gravity.N-body simulation of point-like dark matter agrees well with the galactic power spectrum as inferred from comprehensive sky surveys. Yet, at the scale of a single galaxy, N-body simulations predict densities that diverge toward galactic centers, while observational evidence strongly suggests constant densities. There have emerged extensions to Einstein gravity that predict a dark matter candidate with Newtonian gravitational interactions at large separation but which diminish linearly to zero at small separation. The N-body code GADGET-2 will be augmented to permit distinct gravitational interactions between particles, with focus on deviations from point-mass behavior as predicted by recent models featuring multiple metric tensors. The effect of these deviations on large-scale structure will be compared against existing sky surveys. Research outcomes will either lessen tension between large-scale and small-scale dark matter observations, or exclude these specific models. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.

物理学家和天文学家最终确定了我们宇宙中很大一部分物质是黑暗的，构成未知。尽管在数十亿年内对暗物质进行建模的计算机模拟与大于星系大小的观察结果一致，但与数据的分歧保持在单个星系的大小上。爱因斯坦对重力描述的最新扩展产生了一种新型的暗物质，该暗物质与单个星系大小的数据一致。通过超级计算机模拟，与东京大学的Naoki Yoshida博士和日本的宇宙物理学和数学研究所共同合作，本研究将调查这种形式的暗物质是否还可以与大型大型数据同一致。这项研究有可能解决天文学家和天体物理学家之间的长期分歧，并可能指出对爱因斯坦重力的更富有成果的扩展。对点状暗物质的n型模拟与全面的天空调查所推论的银河系强力谱非常吻合。然而，根据单个星系的规模，N体模拟预测了向银河中心差异的密度，而观察性证据则强烈表明恒定密度。在爱因斯坦重力上出现了扩展，该重力预测了牛顿重力相互作用的暗物质候选者，但在很大的分离下，在小分离时线性降低至零。 N体密码小工具2将被增强以允许粒子之间的明显重力相互作用，重点是与点质量行为的偏差，如最近具有多个度量张量的模型所预测的那样。这些偏差对大规模结构的影响将与现有的天空调查进行比较。研究成果将减少大规模和小规模的暗物质观察之间的张力，或者排除这些特定模型。该NSF EAPSI奖与日本促进科学学会合作。