String compactification, generalized geometry, and 4D physics

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。提出了一个广泛的研究计划，以阐明构成弦理论内部维度的几何结构，并克服从该几何中提取四维粒子物理的关键障碍。将研究的两个主要领域是翘曲紧化和广义几何。另外三个领域包括粒子物理局部模型的全局嵌入，弦理论LHC逆问题，以及传统弦理论真空从过去更对称的阶段产生的宇宙学模型。智力优势：目前研究的弦理论几乎所有紧化都是扭曲紧化。提出了利用弦对偶性推导扭曲对四维化的精确影响，并检验扭曲紧化的非微扰修正。第一个项目对于可靠地计算弦理论模型中的微扰质谱至关重要。第二项将增加对最近的模稳定和产生小马约拉纳中微子质量和mu项的非摄动机制的信心。模稳定和暴胀情景的另一个关键因素是内部磁通，现在推广到非几何磁通。非几何通量通过破坏额外维度作为流形的通常6D解释，从根本上改变了我们对内部几何的理解。在此背景下，提出了一套更精确地表征广义通量紧化的策略，并提取了d膜的四维物理。在剩下的三个拟议项目中，有两个进一步推进了将弦理论与四维物理联系起来的目标，其规模很快将在大型强子对撞机上进行探索。最后一个项目提供了一个长期推测的想法的具体实现，即传统弦理论真空描述了一个更对称的基础理论的对称破缺阶段。更广泛的影响：PI为布林莫尔学院带来了令人兴奋的弦理论和基本粒子物理学的前沿。有监督的研究将促进科学和工程领域的多样性，通过建立布林莫尔对有才华的本科女性（其中四分之一是有色人种学生）和男女同校的研究生进行个性化研究指导的强大传统，并具有良好的招聘和留住记录。博士项目，作为对地区文理学院院系的补充，扩大了高能物理的研究活动。该计划利用了现有的基础设施：部门讨论会，三学院PACT研讨会，以及与宾夕法尼亚大学的联系。PI将在蓬勃发展的文理学院开展适合高能理论课程需要的理论午餐和访客计划。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).A broad program of research is proposed to elucidate the geometrical structure that underlies the internal dimensions of string theory, and to overcome key obstacles to extracting 4D particle physics from this geometry. The two main areas that will be investigated are warped compactifications and generalized geometry. Three additional areas include global embeddings of local models of particle physics, the string theory LHC inverse problem, and a cosmological model in which conventional string theory vacua arise from a more symmetric phase in the past. Intellectual Merit: Nearly all compactifications of string theory currently under sudy are warped compactifications. It is proposed to apply string duality to derive the precise effect of warping in the reduction to 4D, and to check nonperturbative corrections to warped compactifications. The first project is essential for reliably computing perturbative mass spectra in string theory models. The second will increase confidence in recent nonperturbative mechanisms for moduli stabilization and for the generation of hierarchically small Majorana neutrino masses and mu-terms. Another critical ingredient in moduli stabilization and inflationary scenarios is internal magnetic flux, now generalized to nongeometric flux. The nongeometric flux radically alters our understanding of the internal geometry by destroying the usual 6D interpretation of the extra dimensions as a manifold. A set of strategies is outlined to more precisely characterize compactifications with generalized flux, and to extract the 4D physics of D-branes in this background. Of the remaining three proposed projects, two further advance the goal of connecting string theory to 4D physics at the scale soon to be probed at the LHC. The last project provides a concrete realization of a long speculated idea that conventional string theory vacua describe a symmetry breaking phase of a more symmetric underlying theory. Broader Impacts: The PI brings the exciting frontiers of string theory and elementary particle physics to Bryn Mawr College. Supervised research will foster diversity in science and engineering, by building on Bryn Mawr's strong tradition of individualized research mentoring of talented undergraduate women (a quarter of whom are students of color) and coeducational graduate students, with a proven track record of recruitment and retention. The Ph.D. program, as a feeder to the faculties of regional liberal arts colleges, expands research activity in high energy physics. The plan exploits existing infrastructure: departmental colloquia, the Tri-College PACT seminar, and connections to the University of Pennsylvania. The PI will initiate a Theory Lunch and a visitor program tailored to the needs of a high energy theory program at a thriving liberal arts college.