Collaborative Research: Imaging the Beginning of Time from the South Pole: Observations with the Full SPUD Array

合作研究：从南极想象时间的开始：用完整的 SPUD 阵列进行观测

• 批准号: 1145248
• 负责人: Chao-Lin Kuo
• 金额: $ 67.63万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1145248&HistoricalAwards=false
• 关键词: Collaborative; Research; Imaging; Beginning; Time

There is mounting evidence that the entire observable Universe was spawned in a dramatic superluminal "Inflation" of a subnuclear volume. This violent acceleration of matter would have produced a Cosmic Gravitational-wave Background (CGB), the amplitude of which measures the energy scale at which Inflation occurred. The CGB imprints a faint signature in the polarization of the Cosmic Microwave Background (CMB) with the amplitude parameterized by the ratio of tensor-to-scalar modes, r = T/S. Many theoretically favored models of Inflation produce this ratio between 0.01 and 0.1, corresponding to average amplitude from 30 to 100 nanoKelvins for the resulting CMB B-mode polarization patterns where they peak on scales of degrees. With this award, researchers from three U.S. institutions will focus on exploring and ultimately detecting the CGB polarization signature, which is arguably the most important goal in cosmology today. In 2005, the Community Task Force on CMB Research identified a target sensitivity of that ratio equaling to 0.02 as an immediate goal to detect the Inflationary gravitational waves imprint in the CMB polarization that pertain to the standard cosmological model. The newly installed 'Small Polarimeter Upgrades for DASI' (SPUD) reconfigured a five- receivers telescope to the "South Pole Inflationary Cosmology Experiment" (SPICE) that will: (a) Complete the CGB search in CMB B-mode polarization at 150 GHz, reaching depths which based on current sensitivity performance, that will detect the Inflationary CGB for r 0.02; (b) Prove that this signal is cosmic in origin while separately measuring the Galactic foreground contamination at its minimum; (c) Detect gravitational lensing of CMB polarization on scales of ~1 degree, probing the CGB to the lensing confusion limit for degree-scale observations (r 0.01) if the energy scale of Inflation is low; and (d) Surpass the instrumental sensitivity goals set forth for 2013 by the 2005 CMB Task Force recommendations. Detection of the CGB waves would be to Inflation what the discovery of the CMB radiation was to the Big Bang theory. Indeed, its impact may be even broader as nuclear physics had matured enough prior to the establishment of the "hot" Big Bang model, while Inflation directly bears on the current frontiers of fundamental physics: the union of general relativity and quantum mechanics, string theory, and the highest accessible energies. Cosmology and research in Antarctica both capture the public imagination, making this combination a remarkably effective vehicle for stimulating interest in science and train students.

越来越多的证据表明，整个可观测的宇宙是在一个亚核体积的戏剧性超光速“膨胀”中产生的。这种剧烈的物质加速会产生宇宙引力波背景（CGB），其振幅测量了暴胀发生时的能量尺度。CGB在宇宙微波背景（CMB）的偏振中留下了一个微弱的签名，其振幅由张量与标量模式的比值r = T/S参数化。许多理论上受欢迎的暴胀模型产生的这个比率在0.01和0.1之间，对应于所产生的CMB B模式偏振模式的平均振幅从30到100纳开尔文，其中它们在度的尺度上达到峰值。有了这个奖项，来自三个美国机构的研究人员将专注于探索并最终检测CGB偏振特征，这可以说是当今宇宙学中最重要的目标。2005年，CMB研究社区工作组确定了该比率等于0.02的目标灵敏度作为直接目标，以检测标准宇宙学模型中CMB偏振中的暴胀引力波印记。新安装的“DASI小型偏振仪升级"（SPUD）重新配置了一个五接收器望远镜，用于“南极暴胀宇宙学实验”（SPICE），该实验将：（a）在150 GHz的CMB B模式偏振中完成CGB搜索，达到基于当前灵敏度性能的深度，将检测r0.02的暴胀CGB;（B）证明这一信号起源于宇宙，同时单独测量银河前景污染的最低程度;（c）在~1度的尺度上探测CMB偏振的引力透镜效应，探测CGB的透镜效应混淆极限，以进行度尺度观测（r 0.01）如果通货膨胀的能量标度较低;以及（d）超过2005年资本市场管理局工作队建议为2013年设定的工具敏感性目标。发现CGB波对于暴胀理论的意义，就像发现CMB辐射对于大爆炸理论的意义一样。事实上，它的影响可能会更广泛，因为核物理在“热”大爆炸模型建立之前已经足够成熟，而暴胀直接关系到基础物理学的当前前沿：广义相对论和量子力学的结合，弦理论和最高可获得的能量。南极洲的宇宙学和研究都抓住了公众的想象力，使这种结合成为激发科学兴趣和培养学生的非常有效的工具。