An outstanding open issue in our quest for physics beyond Einstein is the unification of general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading approach toward this goal. At its heart is the central lesson of GR: gravity is a manifestation of spacetime geometry. Thus, the approach emphasizes the quantum nature of geometry and focuses on its implications in extreme regimes—near the big bang and inside black holes—where Einstein’s smooth continuum breaks down. We present a brief overview of the main ideas underlying LQG and highlight a few recent advances. This report is addressed to non-experts.

中文翻译：

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圈量子引力的简短回顾

在我们寻求超越爱因斯坦的物理学时，一个悬而未决的悬而未决的问题是广义相对论 (GR) 和量子物理学的统一。圈量子引力（LQG）是实现这一目标的主要方法。它的核心是 GR 的核心教训：引力是时空几何的一种表现形式。因此，该方法强调几何的量子性质，并关注其在极端情况下的影响——大爆炸附近和黑洞内部——爱因斯坦的平滑连续体在这些情况下被破坏。我们简要概述了 LQG 的主要思想，并强调了一些最近的进展。本报告面向非专家。