2021/04/09 by Abhay Ashtekar, Eugenio Bianchi · 1 voice · 3 citations
Physics and Astronomy · #gr-qc #hep-th
paper · pdf · doi:10.1088/1361-6633/abed91
published as Rep. Prog. Phys. 84, 042001 (2021) · 35 pages, 6 figures; Key Issues Review commissioned by the Journal
arxiv created 2021/04/09 · arxiv published 2021/04/09 · arxiv updated 2021/04/12
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.