This collection of seminal papers from PRD highlights research that remains central to developments today in particle physics, quantum field and string theory, gravitation, cosmology, and particle astrophysics.

Collection

The author studies a family of two-dimensional Jackiw–Teitelboim (JT) supergravites, and, by using string theory techniques, he gives them a complete definition to all orders in the topological expansion. This construction provides a non–perturbative formulation for the JT supergravity that is well–defined and stable. Furthermore, by using a combination of analytical and numerical methods, the author shows explicitly how non–perturbative physics can be extracted for JT gravity within this framework.

Clifford V. Johnson
Phys. Rev. D 103, 046013 (2021)

The authors discuss in detail a popular scenario to alleviate the current Hubble tension (different measurements of the expansion rate of the Universe show a 4.4 $\sigma$ discrepancy), namely “early dark energy”. Hereby a false vacuum early on acts as an additional repulsive force (dark energy) but decays quickly enough to remain consistent with numerous other observational data. Contrary to the usual approach, a first order phase transition is considered, allowing in a minimal model a reduction of the tension to 2.5 $\sigma$.

The authors construct stationary solutions of magnetized, viscous, thick accretion disks around a Schwarzschild black hole, that are not self-gravitating and have a constant angular momentum. They provide a detailed analysis of these tori (the Polish donut model) and shed light on the dynamical stability of these tori, which, absent viscosity, are known to exhibit runaway instability. Given the importance of accretion disks in astrophysical phenomena, this is a timely study.

Behind the obvious goal of finding a consistent quantum theory of gravity lingers a question, namely if gravity is “quantized” at all. The authors work out in detail a recent proposal to detect quantum noise induced by gravitons in LIGO, and add another example, decoherence of massive particles induced by gravitons. Both concepts would prove the existence of quantum gravity and gravitons, the latter potentially in a tabletop experiment.

Juan Maldacena and Douglas Stanford present a thorough analysis of the Sachdev-Ye-Kitaev model.

Juan Maldacena and Douglas Stanford
Phys. Rev. D 94, 106002 (2016)

Collection

The LIGO and Virgo collaborations establish the interpretation of the detector signal GW150914 as a gravitational-wave event generated by the merger of astrophysical binary black holes.

B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration)
Phys. Rev. D 93, 122003 (2016)

B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration)
Phys. Rev. D 93, 122004 (2016)

Collection

Following the discovery of the Higgs boson, experimental collaborations carefully study its decays to test the properties of the new particle against predictions.

S. Chatrchyan et al. (CMS Collaboration)
Phys. Rev. D 89, 092007 (2014)

G. Aad et al. (ATLAS Collaboration)
Phys. Rev. D 90, 052004 (2014)

Collection

APS Editor in Chief, Michael Thoennessen, discusses a new opportunity for communicating authors to include their pronouns together with their contact email in order to promote a more respectful, inclusive, and equitable environment.

The authors provide a detailed analysis of conjectured properties and symmetries of quantum gravity.

Tom Banks and Nathan Seiberg
Phys. Rev. D 83, 084019 (2011)

Collection

The Muon (g-2) Collaboration reports the final results of the measurement of the muon anomalous magnetic moment.

G. W. Bennett et al. (Muon g-2 Collaboration)
Phys. Rev. D 73, 072003 (2006)

Collection

From nature’s tiniest particles to waves that traverse the Universe—physicists remember resounding finds from the last half-century.

Special Feature in Physics