Theoretical High Energy Physics

该奖项的研究主题是超弦理论，它是将自然界的四种基本力（电磁力、弱力、强力和引力）完全统一到一个符合所有已知物理原理（包括量子力学和广义相对论）的框架中的最有希望的候选者。弦是一维的延伸物体，在时间演化下，它扫过起伏的二维表面。对于弱耦合，超弦理论动力学的定量理解需要精确的数学方法来定义和计算这些波动表面的量子力学。该奖项下开展的研究展示了如何克服这些效应的定义和计算方面的某些长期困难，并得出具体而美观的定量公式。上述结果具有令人兴奋的应用，包括首次可靠地计算了一些重要的物理量。 第一个是无质量超弦的散射振幅，这是超弦理论的关键动力学量之一。 第二个是所谓的宇宙学常数，它提供了广义相对论方程的一个可能的修正，其影响与宇宙中暗物质和暗能量的存在有关。 弦理论作为量子引力理论，有望使宇宙学常数的计算成为可能。D'Hoker的结果表明平坦时空中的宇宙学常数必须为零，并提供了（更现实的）非超对称模型的一般表达式。

The research topic of this award is superstring theory, which is the most promising candidate for a complete unification of the four fundamental forces of Nature (electro-magnetic, weak, strong and gravitational) into a framework consistent with all known physical principles, including quantum mechanics and generalrelativity. Strings are one-dimensional extended objects which, under time-evolution, sweep out fluctuating two-dimensional surfaces. The quantitative understanding of the dynamics of superstring theory, for weak coupling, requires precise mathematical methods for defining and calculating the quantum mechanics of these fluctuating surfaces. The research carried out under this award demonstrates how to overcome certain longstanding difficulties with both the definition and calculation of these effects and leads to concrete and beautiful quantitative formulas.The above results have exciting applications, including the first reliable calculation, at two-loop order, of a number of physically important quantities. The first is the scattering amplitude of massless superstrings, one of the key dynamical quantities of superstring theory. The second is the so-called cosmological constant, which provides a possible modification of the equations of general relativity, and whose effects interferewith the presence in the Universe of Dark Matter and Dark Energy. String theory, being a theory of quantum gravity, is expected to make the calculation of the cosmological constant possible. D'Hoker's results show that the cosmological constant in flat space-time must vanish, and provides a general expression in(more realistic) non-supersymmetric models.