Lectures on the Infrared Structure of Gravity and Gauge Theory

By Andrew Strominger. 2017

994 citations recorded by the source corpus.

This is a redacted transcript of a course given by the author at Harvard in spring semester 2016. It contains a pedagogical overview of recent developments connecting the subjects of soft theorems, the memory effect and asymptotic symmetries in four-dimensional QED, nonabelian gauge theory and gravity with applications to black holes. The lectures may be viewed online at this https URL. Please send typos or corrections to strominger@physics.this http URL.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6050c92929c9da0362fbf115c88d0b0b582266ee

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Citations in the corpus

Islands outside the horizon (2019, background): “If this setup is obtained from approximating a near-extremal black hole in flat space, it is probably necessary to include also a discussion of the soft gravitons [44].”
The cosmological bootstrap: inflationary correlators from symmetries and singularities (2018, neutral): “Indeed, even some first hints for such a description, seen in perturbation theory, involve much more alien combinatorial, geometric and number-theoretic ideas [9–16], from which the physics of spacetime and quantum mechanics—locality and unitarity—emerge as derivative notions, with a huge amount lef”
Celestial amplitudes and conformal soft theorems (2019, background): “The relationship between energetic soft limits and asymptotic symmetries of gauge theory and gravity is well-established (see [41, 48, 49]).”
Conformally soft photons and gravitons (2018, background): “Combining Jw with its I− counterpart gives the soft photon current [8, 20].”
Celestial operator products of gluons and gravitons (2019, neutral): “This symmetry acts on the celestial sphere at null infinity, with Lorentz transformations generating the global SL(2,C) subgroup [3].”
Lectures on celestial amplitudes (2021, background): “For recent reviews on how infrared physics leads to celestial holography see [20,21,24].”
Conformally soft theorem in gauge theory (2019, background): “Recently there has been interest in and explicit construction of amplitudes in a conformal basis on the celestial sphere [1–16], in which the conformal action is trivial but translation invariance is hidden.”
Classical and quantum results on logarithmic terms in the soft theorem in four dimensions (2018, background): “Soft theorems [1–12] have been analyzed recently from different perspectives, both using asymptotic symmetries [13–36] and also by direct analysis of amplitudes in field theory and string theory [37–87].”
Carrollian physics at the black hole horizon (2019, background): “The symmetry group of asymptotically flat spacetimes is the Bondi-Metzner-Sachs (BMS) group; it is an infinite-dimensional extension of the Poincaré group, and its connection with soft theorems has shead a new light on the infrared structure of gravitational theories [8].”
Scattering of spinning black holes from exponentiated soft factors (2018, methodology): “iew of soft theorems. Finally, it would be also interesting to see a link between the exponentiation presented here and the exponentiation of IR divergences that has been known in QED for a long time [2,10,55]. The latter one has recently appeared in the computation of tail eects from the EFT perspe”
Bridging Carrollian and celestial holography (2022, methodology): “In this section, we review how to construct boundary operators by performing a large-r expansion around I + and I − [14].”
Modular Hamiltonians on the null plane and the Markov property of the vacuum state (2017, background): “It would be interesting to explore the relations between asymptotic symmetries at infinity that have been studied in the literature (see [40] for a recent review) with the infinite number modular symmetries for regions with future horizon lying on a common null cone that we are studying here.”
Infrared Divergences in QED, Revisited (2017, positive): “1 Introduction Recently it has been shown [1–5] (see [6] for a review) that the infrared (IR) sector of all abelian gauge theories, including QED, is governed by an infinite-dimensional symmetry group.”
Celestial Holography (2021, background): “In particular, the Ward identities for asymptotic symmetries manifest as soft theorems of the S-matrix (see [8] and references therein) 〈out|QS−SQ|in〉 = 0 ⇔ 〈out|a(ω)S|in〉 ∝ ω→0 〈out|S|in〉.”
Soft limits of Yang-Mills amplitudes and conformal correlators (2019, background): “This result confirms conclusions reached by using Yang-Mills theory formulated in curvilinear coordinates, as pioneered by Strominger.”
Conformal basis for flat space amplitudes (2017, background): “See [24] for a comprehensive review of this subject.”
Superboost transitions, refraction memory and super-Lorentz charge algebra (2018, background): “du d2z spuN^zzD3 zY z uN^zzD3 zY zq (5.64) where we keep YAB A Yzpz;zqB z Yzpz;zqB z arbitrary. In the case of meromorphic superLorentz tranformations, this reproduces equation (5.3.17) of [12] (up to a conventional global sign). This concludes our checks with the literature. It shows that the Ward”