近日，加拿大圆周研究所的Johanna Borissova及其研究团队取得一项新进展。经过不懈努力，他们对四维洛伦兹单纯形量子引力中的尖刺和棘刺进行研究。相关研究成果已于2024年10月22日在国际知名学术期刊《高能物理杂志》上发表。

该研究团队研究了四维洛伦兹量子雷吉计算中的尖刺和棘刺构型。研究人员发现体边长度的任意幂的期望值都是有限的。为此，研究人员探索了雷吉振幅的新型渐近区域，其中部分边远大于其余边。在这种渐近区域中，振幅大大简化，所得表达式的几何解释涉及降维，这可能在全息术中有应用前景。

据悉，诸如量子雷吉计算和自旋泡沫等简化的量子引力方法，包含了一些体边可以变得任意大而边界边保持较小的构型。尖刺和棘刺是这种构型的典型例子。这些构型对期望的连续极限构成了重大挑战，因为在连续极限中，边的平均长度应该变得非常小。

附：英文原文

Title: Spikes and spines in 4D Lorentzian simplicial quantum gravity

Author: Borissova, Johanna, Dittrich, Bianca, Qu, Dongxue, Schiffer, Marc

Issue&Volume: 2024-10-22

Abstract: Simplicial approaches to quantum gravity such as quantum Regge calculus and spin foams include configurations where bulk edges can become arbitrarily large while the boundary edges are kept small. Spikes and spines are prime examples for such configurations. They pose a significant challenge for a desired continuum limit, for which the average lengths of edges ought to become very small. Here we investigate spike and spine configurations in four-dimensional Lorentzian quantum Regge calculus. We find that the expectation values of arbitrary powers of the bulk length are finite. To that end, we explore new types of asymptotic regimes for the Regge amplitudes, in which some of the edges are much larger than the remaining ones. The amplitudes simplify considerably in such asymptotic regimes and the geometric interpretation of the resulting expressions involves a dimensional reduction, which might have applications to holography.

DOI: 10.1007/JHEP10(2024)150

Source: https://link.springer.com/article/10.1007/JHEP10(2024)150