Results 71 to 80 of about 2,908,412 (339)
Tree-level scattering amplitudes in nonlocal field theories
Journal of High Energy Physics, 2021 We prove in two ways that, for a special class of nonlocal field theories consistent with linear and non-linear stability at the classical level, and with unitarity and super-renormalizability or finiteness at the quantum level, the n-point tree-level ...
Leonardo Modesto, Gianluca Calcagni
doaj +1 more source
On scalar and vector fields coupled to the energy-momentum tensor
Journal of High Energy Physics, 2018 We consider theories for scalar and vector fields coupled to the energy-momentum tensor. Since these fields also carry a non-trivial energy-momentum tensor, the coupling prescription generates self-interactions. In analogy with gravity theories, we build
Jose Beltrán Jiménez +2 more
doaj +1 more source
Field theory for gravity at all scales [PDF]
Proceedings of the MG15 Meeting on General Relativity 2018 (2022)
1017, 2019 We review here the main advances made by using effective field theories (EFTs) in classical gravity, with notable focus on those unique to the EFTs of post-Newtonian (PN) gravity. We then proceed to overview the various prospects of using field theory to study the real-world gravitational wave (GW) data, as well as to ameliorate our fundamental ...
arxiv +1 more source
Quantum gravity fluctuations in the timelike Raychaudhuri equation
Journal of High Energy Physics, 2023 We consider a timelike geodesic congruence in the presence of perturbative quantum fluctuations of the spacetime metric. We calculate the change in the volume of a bundle of geodesics due to such fluctuations and thereby obtain a quantum-gravitationally ...
Sang-Eon Bak +3 more
doaj +1 more source
On Classical Equivalence Between Noncritical and Einstein Gravity : The AdS/CFT Perspectives [PDF]
, 2012 We find that noncritical gravity, a special class of higher derivative gravity, is classically equivalent to Einstein gravity at the full nonlinear level. We obtain the viscosity-to-entropy ratio and the second order transport coefficients of the dual fluid of noncritical gravity to all orders in the coupling of higher derivative terms. We also compute
arxiv +1 more source
Corners of gravity: the case of gravity as a constrained BF theory
Journal of High Energy Physics, 2021 Following recent works on corner charges we investigate the boundary structure in the case of the theory of gravity formulated as a constrained BF theory.
Remigiusz Durka, Jerzy Kowalski-Glikman
doaj +1 more source
Null infinity as an open Hamiltonian system
Journal of High Energy Physics, 2021 When a system emits gravitational radiation, the Bondi mass decreases. If the Bondi energy is Hamiltonian, it can thus only be a time-dependent Hamiltonian. In this paper, we show that the Bondi energy can be understood as a time-dependent Hamiltonian on
Wolfgang Wieland
doaj +1 more source
How unimodular gravity theories differ from general relativity at quantum level [PDF]
, 2015 We investigate path integral quantization of two versions of unimodular gravity. First a fully diffeomorphism-invariant theory is analyzed, which does not include a unimodular condition on the metric, while still being equivalent to other unimodular ...
R. Bufalo +3 more
semanticscholar +1 more source
A Macroscopically Effective Lorentz Gauge Theory of Gravity [PDF]
Classical and Quantum Gravity, 33 (2016) 235006, 2016 Following the ideas of effective field theories, we derive classically effective field equations of recently developed Lorentz gauge theory of gravity. It is shown that Newton's gravitational constant emerges as an effective coupling parameter if an extremely small length is integrated out of the underlying theory.
arxiv +1 more source
Gravitational SL(2, ℝ) algebra on the light cone
Journal of High Energy Physics, 2021 In a region with a boundary, the gravitational phase space consists of radiative modes in the interior and edge modes at the boundary. Such edge modes are necessary to explain how the region couples to its environment.
Wolfgang Wieland
doaj +1 more source