scholarly journals Brans-Dicke theory in Bondi-Sachs form: Asymptotically flat solutions, asymptotic symmetries, and gravitational-wave memory effects

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Shammi Tahura ◽  
David A. Nichols ◽  
Alexander Saffer ◽  
Leo C. Stein ◽  
Kent Yagi
Keyword(s):  
Gravitational Wave ◽  
Memory Effects ◽  
Asymptotically Flat ◽  
Asymptotic Symmetries

scholarly journals BMS flux algebra in celestial holography

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Laura Donnay ◽  
Romain Ruzziconi
Keyword(s):  
Solution Space ◽  
Coadjoint Representation ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Asymptotically Flat ◽  
Flat Spacetime ◽  
Stress Energy ◽  
Momentum Fluxes ◽  
Non Local ◽  
Asymptotic Symmetries

Abstract Starting from gravity in asymptotically flat spacetime, the BMS momentum fluxes are constructed. These are non-local expressions of the solution space living on the celestial Riemann surface. They transform in the coadjoint representation of the extended BMS group and correspond to Virasoro primaries under the action of bulk superrotations. The relation between the BMS momentum fluxes and celestial CFT operators is then established: the supermomentum flux is related to the supertranslation operator and the super angular momentum flux is linked to the stress-energy tensor of the celestial CFT. The transformation under the action of asymptotic symmetries and the OPEs of the celestial CFT currents are deduced from the BMS flux algebra.

scholarly journals Asymptotic symmetry of four dimensional Einstein-Yang-Mills and Einstein-Maxwell theory

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Nabamita Banerjee ◽  
Tabasum Rahnuma ◽  
Ranveer Kumar Singh
Keyword(s):  
Asymptotic Symmetry ◽  
Maxwell Theory ◽  
Asymptotically Flat ◽  
Yang Mills ◽  
Alternative Approach ◽  
Pure Gravity ◽  
Asymptotic Symmetries ◽  
Symmetry Algebras

Abstract Asymptotic symmetry plays an important role in determining physical observables of a theory. Recently, in the context of four dimensional asymptotically flat pure gravity and $$ \mathcal{N} $$ N = 1 supergravity, it has been proposed that OPEs of appropriate celestial amplitudes can be used to find their asymptotic symmetries. In this paper we find the asymptotic symmetry algebras of four dimensional Einstein-Yang-Mills and Einstein-Maxwell theories using this alternative approach, namely using the OPEs of their respective celestial amplitudes. The algebra obtained here are in agreement with the known results in the literature.

scholarly journals Asymptotic symmetries at null-infinity for the Rarita-Schwinger field with magnetic term

2021 ◽  
Author(s):  
Bilyana Lyudmilova Tomova
Keyword(s):  
Magnetic Charge ◽  
Flat Space ◽  
Space Time ◽  
Boundary Term ◽  
Null Infinity ◽  
Dimensional Algebra ◽  
Asymptotically Flat ◽  
Yang Mills ◽  
Infinite Dimensional ◽  
Asymptotic Symmetries

Abstract In this paper we study the magnetic charges of the free massless Rarita-Schwinger field in four dimensional asymptotically flat space-time. This is the first step towards extending the study of the dual BMS charges to supergravity. The magnetic charges appear due to the addition of a boundary term in the action. This term is similar to the theta term in Yang-Mills theory. At null-infinity an infinite dimensional algebra is discovered, both for the electric and magnetic charge.

scholarly journals Gravitational breathing memory and dual symmetries

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ali Seraj
Keyword(s):  
General Relativity ◽  
Gauge Theory ◽  
Scalar Field ◽  
Memory Effects ◽  
Balance Equations ◽  
Symmetry Principle ◽  
Dual Formulation ◽  
Physical Role ◽  
Asymptotic Symmetries

Abstract Brans-Dicke theory contains an additional propagating mode which causes homogeneous expansion and contraction of test bodies in transverse directions. This “breathing” mode is associated with novel memory effects in addition to those of general relativity. Standard tensor mode memories are related to a symmetry principle: they are determined by the balance equations corresponding to the BMS symmetries. In this paper, we show that the leading and subleading breathing memory effects are determined by the balance equations associated with the leading and “overleading” asymptotic symmetries of a dual formulation of the scalar field in terms of a two-form gauge field. The memory effect causes a transition in the vacuum of the dual gauge theory. These results highlight the significance of dual charges and the physical role of overleading asymptotic symmetries.

scholarly journals Explorations of the infinite regions of spacetime

2020 ◽  
Vol 29 (10) ◽  
pp. 2030007
Author(s):  
Florian Beyer ◽  
Jörg Frauendiener ◽  
Jörg Hennig
Keyword(s):  
Gravitational Wave ◽  
Current Knowledge ◽  
Sufficient Conditions ◽  
Einstein Equations ◽  
Material System ◽  
Null Infinity ◽  
Numerical Work ◽  
Asymptotically Flat ◽  
Outgoing Radiation ◽  
Flat Spacetimes

An important concept in Physics is the notion of an isolated system. It is used in many different areas to describe the properties of a physical system which has been isolated from its environment. The interaction with the “outside” is then usually reduced to a scattering process, in which incoming radiation interacts with the system, which in turn emits outgoing radiation. In Einstein’s theory of gravitation, isolated systems are modeled as asymptotically flat spacetimes. They provide the appropriate paradigm for the study of gravitational waves and their interaction with a material system or even only with themselves. In view of the emerging era of gravitational wave astronomy, in which gravitational wave signals from many different astrophysical sources are detected and interpreted, it is necessary to have a foundation for the theoretical and numerical treatments of these signals. Furthermore, from a purely mathematical point of view, it is important to have a full understanding of the implications of imposing the condition of asymptotic flatness onto solutions of the Einstein equations. While it is known that there exists a large class of asymptotically flat solutions of Einstein’s equations, it is not known what the necessary and sufficient conditions at infinity are that have to be imposed on initial data so that they evolve into regular asymptotically flat spacetimes. The crux lies in the region near spacelike infinity [Formula: see text] where incoming and outgoing radiation “meet”. In this paper, we review the current knowledge and some of the analytical and numerical work that has gone into the attempt to understand the structure of asymptotically flat spacetimes near spacelike and null-infinity.

scholarly journals Asymptotically Flat Boundary Conditions for the U(1)3 Model for Euclidean Quantum Gravity

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 68
Author(s):  
Sepideh Bakhoda ◽  
Hossein Shojaie ◽  
Thomas Thiemann
Keyword(s):  
General Relativity ◽  
Gauge Theory ◽  
Quantum Gravity ◽  
Boundary Conditions ◽  
Crucial Role ◽  
Test Laboratory ◽  
Asymptotically Flat ◽  
Generally Covariant ◽  
Asymptotic Symmetries

A generally covariant U(1)3 gauge theory describing the GN→0 limit of Euclidean general relativity is an interesting test laboratory for general relativity, specially because the algebra of the Hamiltonian and diffeomorphism constraints of this limit is isomorphic to the algebra of the corresponding constraints in general relativity. In the present work, we the study boundary conditions and asymptotic symmetries of the U(1)3 model and show that while asymptotic spacetime translations admit well-defined generators, boosts and rotations do not. Comparing with Euclidean general relativity, one finds that the non-Abelian part of the SU(2) Gauss constraint, which is absent in the U(1)3 model, plays a crucial role in obtaining boost and rotation generators.

Real and complex asymptotic symmetries in quantum gravity, irreducible representations, polygons, polyhedra, and the A, D, E series

1992 ◽  
Vol 338 (1650) ◽  
pp. 271-299 ◽  
Keyword(s):  
General Relativity ◽  
Quantum Gravity ◽  
Irreducible Representations ◽  
Symmetry Groups ◽  
Regular Polygons ◽  
Lorentzian Space ◽  
Asymptotically Flat ◽  
Irreducible Unitary Representations ◽  
The Common ◽  
Asymptotic Symmetries

The Bondi-Metzner-Sachs group B is the common asymptotic group of all asymptotically flat (lorentzian) space-times, and is the best candidate for the universal symmetry group of general relativity. However, in quantum gravity, complexified or euclidean versions of general relativity are frequently considered, and the question arises: Are there similar symmetry groups for these versions of the theory? In this paper it is shown that there are such analogues of B and a variety of further ones, either real in any signature, or complex. The relationships between these various groups are described. Irreducible unitary representations (IRS) of the complexification CB of B itself are analysed. It is proved that all induced IRS of CB arise from IRS of compact 'little groups’. It follows that some IRS of CB are controlled by the IRS of the ‘ A,D,E ' series of finite symmetry groups of regular polygons and polyhedra in ordinary euclidean 3-space. Possible applications to quantum gravity are indicated.

scholarly journals General null asymptotics and superrotation-compatible configuration spaces in d ≥ 4

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
F. Capone
Keyword(s):  
Einstein Equations ◽  
Time Dependent ◽  
Boundary Structure ◽  
Configuration Spaces ◽  
Two Dimensional ◽  
General Boundary Conditions ◽  
Cross Sectional ◽  
Asymptotically Flat ◽  
The Relationship ◽  
Asymptotic Symmetries

Abstract We address the problem of consistent Campiglia-Laddha superrotations in d > 4 by solving Bondi-Sachs gauge vacuum Einstein equations at the non-linear level with the most general boundary conditions preserving the null nature of infinity. We discuss how to generalise the boundary structure to make the configuration space compatible with supertanslation-like and superrotation-like transformations. One possibility requires the time-independent boundary metric on the cuts of "Image missing" to be non-Einstein, while the other sticks to Einstein but time-dependent metrics. Both are novel features with respect to the four dimensional case, where time-dependence of the two-dimensional cross-sectional metric is not required and the Einstein condition is trivially satisfied. Other cases are also discussed. These conditions imply that the configuration spaces are not asymptotically flat in the standard sense. We discuss the implications on the construction of the phase space and the relationship with soft scattering theorems. We show that in even spacetime dimensions, the initial data compatible with such asymptotic symmetries produce maximally polyhomogeneous expansions of the metric and we advance a potential interpretation of this structure in terms of AdS/CFT and realizations of Ricci-flat holography.

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